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By M. Mirzazadeh

Air cooled crackable and conventional forged steel specimens were tested under reversed push-pull conditions to examine the effect of shot-peening on their high cycle fatigue behaviour (-106 cycles). The steels were tested in the normalized as well as shot-peened conditions. The results showed that shot-peening smooth specimens had little effect on the fatigue limit of the air cooled forged steels and the detrimental effect of the rougher peened surface was not apparent. Microhardness profiles indicated that the shot peening produced a gradient of compressive residual stresses that was greater than that of the loading stresses, suppressing the anticipated beneficial effect on fatigue life. Crack initiation was more likely to occur below the surface. The results indicate that the surface roughness was not a significant factor in controlling the fatigue lives, since they were essentially the same for the non shot-peened and shot-peened steels.

Jan 1, 2010

By Donald MacFadgen

Since 1950, a total of 164 miles of levels and rooms have been roof-bolted in the collieries of the Dominion Coal Company. Roof bolting is an efficient and economic method of sup-port where heavy timber sets or steel booms are necessary for temporary roof support, or where conventional methods of support interfere with the passage of mechanical mining equipment. This paper discusses present roof bolting practices and special bolting applications. THE practice of roof bolting in be collieries of the Dominion Coal Company dates from 1950, when preliminary studies and experiments were carried out in a mechanized room and pillar section of Dominion No. 20 Colliery. These studies were made in close liaison with members of the United States Bureau of Mines who were conducting similar studies. Following the successful application of roof bolting in No. 20 Colliery, this method of roof support was introduced into other collieries

Jan 1, 1963

By W. J. Przybylowicz, V. M. Prozesky, D. de Bruin

"The common style of gold mineralization in the Basal Reef and other auriferous conglomerates of the Witwatersrand Supergroup comprises clusters of gold grains occurring interstitially to quartz and pyrite pebbles as well as gold accumulations attached to the surface of and infilling hairline cracks and fractures in round, compact, detrital pyrite. The latter textural association is generally interpreted as a result of remobilization of originally detrital gold during regional metamorphism and related hydrothermal fluid circulation. There is general agreement that, although gold solubility was low, ore modification occurred during the metahydrothermal event, but uncertainty exists about the magnitude and scale of gold remobilization.Micro-textural and chemical investigation of compact round pyrite and associated gold accumulation has established that gold is preferentially deposited on chemically heterogeneous pyrite surfaces. Combinations of alternating high- and low-As zones in pyrite result in mixed np-type conductivity accompanied by electron exchange and the reduction-driven deposition of gold at the cathode. This model does not explain gold accumulations which are not immediately linked to chemical heterogeneities and it is inferred that an additional control on the deposition of gold was exerted by physical defects which lead to zones of increased charge density and/or areas of focussed conductivity. The inferred precipitation mechanisms suggest that submicrocopic physical and chemical controls are the important factors that determined the sites of gold nucleation and that precipitation mechanisms based on physicochemical changes of the hydrothermal system were not involved. The Basal Reef contains on average close to 5OJo of round, detrital, chemically zoned pyrite which provides a large number of electrochemically active pyrite surfaces. The extremely effective electrochemical precipi- . tation mechanism together with the low solubility of gold in Witwatersrand fluids is the main reason for the spatially restricted remobilization of gold in the conglomerate reefs."

Jan 1, 1994

By J. G. Cullain

In conjunction with the over-all goals of energy conservation at Inco Metals Company, a program of improvement in compressed air utilization was established. Air flows were monitored and compared to calculated requirements to establish efficiency by area. With the cooperation of area management, measures were implemented to reduce nonproductive usage. At the operation, annual savings in power consumption alone were 80,000 dollars. The program is being extended to other mine areas within the Division.

Jan 1, 1979

By Muhammad Zaka Emad

Cemented rockfill (CRF) is a mixture of rock aggregate and binder slurry. It is a stiff backfill, it is fast curing, its operation is simple, placement rate is reasonably high and no drainage is required. The main demerit of CRF is failure of exposed faces causing ore dilution, which can be associated with the fill placement method. This paper discusses the effects of two placement methods being practiced by mines and numerical modelling is used as a tool to evaluate stability of the backfill column. In the first method, practiced in longitudinal retreat mining of a narrow vein deposit, the rockfill is hauled and dumped into the stope with a LHD scooptram. Once dumped, cement slurry is sprayed into the stope. In the second method, a raise situated centrally above the mined stope is used to convey already mixed CRF into the stope. Stopes are mined out transversely in primary and secondary blocks in a sublevel stoping system. Problems of poor mixing in combination with both placement methods are discussed. The two backfill placement methods are analyzed for blast induced vibration damage using the dynamic Flac3D modelling technique accounting for rock mass and fill damping characteristics, and a pressure wave is used to simulate the blast vibrations. Fill heterogeneity has also been considered for the two cases and results are compared.

Jun 1, 2012

By G. F. Trainor

The complex ore body at CNRL?s Horizon mine presents some unique challenges in managing ore and waste delivery. With 25m x 25m ore blocks shovels often take bucket loads from multiple blocks to fill one truck load. With CNRL monitoring 22 different qualities per material a precise calculation of the blended quality of ore on the back of each individual truck is essential to meet the daily blend requirements at the plant. Additionally, one of these qualities must be closely monitored and controlled at a singular level as delivery of certain grade and quantities can cause serious disruptions at the plant. The waste material also requires special handling and delivery for its use in dyke construction for tailings impoundment. Shale materials used in the construction contain high levels of saline that must be contained to prevent seepage into ground water. This paper will discuss how the use of Wenco?s survey-grade GNSS system on shovels, its dispatching algorithm, and fleet management applications give CNRL the ability and confidence to control and report on these three issues.

May 1, 2013

By E. J. Burrough

Coal Reserves The Crowsnest Pass coal fields form part of a greater area which comprises the Inner Foothills belt of the Alberta coal fields and the southeastern coal fields of British Columbia. The most valuable and most extensive reserves of the bituminous coals of Canada are concentrated in this?area, of which the Crowsnest Pass fields form an important part. The extent of these coal reserves together with those of the rest of Canada were recently studied by the Geological Survey of Canada for the Royal Commission on Coal of 1946 (1). Quotin from the report, it is of interest to note that, prior to this work, the most widely known, and in fact the only Canadian-wide estimates of, coal reserves of Canada available to the Commission were those prepared by Dr. Dowling in 1913 (2). At that time it was estimated that Canada's reserves of coal were over twelve hundred billion tons. The more recent estimates of mineable coal for the whole of Canada are of the order of 10 per cent of that figure and are reported. as 99 billion tons, which is further reduced to 40 billion tons on the basis of the estimation of recoverable coal. This considerable divergence in estimated reserves is explained in part by the big difference in the bases of measurements. For example, in the original report, seams of one foot occurring at a depth of 4,000 feet were included in the estimates.

Jan 1, 1951

By R. D. Brown

Higher metal prices have resulted not only in increased exploration and production, but also increased activity in the purchase of mining properties and mines. This article discusses some of the basic income tax considerations to be taken into account on the disposal of an interest in a mining claim or an active mining operation. It notes the importance ofan appropriate allocation of the purchase price amongst the various categories of assets, and discusses the tax implications to both vendor and purchaser of the transfer of the comm on types ofassets involved in mining operations. In the space available, the article can only outline the basic tax considerations, and point to areas where both vendor and purchaser need to be o

Jan 1, 1980

By E. J. Wade

The general location, climatic conditions and access of the Tasu mine are covered briefly, with comments on the Jack of conventional transportation and communication facilities. The Haïda story of Tasu and early at-tempts at production are presented, together with a discussion of the government legislation which throttled exploration and production in the late fifties. General and specific details of local geology, mineralogy and current ore reserves are also covered.

Jan 1, 1968

By B. Dyck, C. Rodgers

ABSTRACT Cameco Corporation is revitalizing its Key Lake Operation uranium mill in northern Saskatchewan. The mill currently uses ammonia stripping in solvent extraction (SX) and ammonia yellowcake precipitation. As part of the revitalization, the company considered installing strong acid stripping in solvent extraction (used at its Rabbit Lake Operation), which would lead to using hydrogen peroxide for uranium precipitation. As part of the process evaluation, tests were carried out to study how the drying temperature in indirect fired dryers would affect the uranium peroxide yellowcake precipitate properties. This paper discusses the test work results, including the relationships between drying temperature and product reactivity with water, product colour, product grade, and energy input requirements.

Jan 1, 2012

By Fritz F. Prugger

In August, 1970, during routine shaft grouting, a major water source was intersected. Water and quicksand under very high pressure entered the shaft at a rate of 65 m3 per minute. The mine and both shafts were flooded. The breach was sealed simultaneously from within the shaft and through a relief hole drilled from surface. The mine was dewatered, rehabilitated and the equipment was restored. Production resumed two years after the accident.

Jan 1, 1979

"In the past year, mining at the Doyon Mine has shifted entirely from open pit to underground. The mine produced 234 692 ounces of gold in 1989 and is expected to produce 225000 ounces in 1990. The Doyon Mill has been running slightly above design capacity, and recovery has increased 3%.IntroductionThe Doyon Mine is located 25 miles east of Rouyn-Noranda, Quebec (Figure I).It is a joint venture owned by Lac Minerals and Cambior, with each holding a 50% interest. Lac Minerals operates the mine under the direction of a management committee.Production at the Doyon Mine began in 1980 with the start up of the Main Zone pit. Shortly thereafter the Doyon Mine became the largest open pit gold producer in Canada.In 1983, a ramp leading to the fourth level and exploration drifts were driven. Results were very encouraging, therefore the decision was made to sink a 2150-foot deep shaft, which was completed in 1986.In mid-1986, production began in the West pit, while underground mining of the West Zone started shortly thereafter, at the end of the same year.In 1987 the mill capacity was increased to 3300 tons per day and the Main Zone underground operations commenced."

Jan 1, 1990

By Paul Johnston

or is it? Mining Automated Loader Technology Application ? Intelligent software mounted in hardware on a remotely controlled scoop. ? Led by INCO, Sudbury, with ? C-CORE, St. John?s ? Automated Mining Systems, Aurora ? Bell Canada, Sudbury ? Laurentian University, Sudbury ? University of Western Ontario, London Completed: March 2000

May 1, 2008

By A. Galibois, H. Monette, J. L. Collins

This paper deals with the problem of caving, which occurs in varying degrees in blast holes before loading. It is shown that the distribution of the amount of caving in materials may be described by a gamma density function. A decision model to determine the optimal depth of over-drilling 'in order to minimize the expected additional cost per hole is described. Two different policies are discussed. In addition, charts which permit the mine operator to realize significant savings have been drawn for different actual situations.

Jan 1, 1971

By C. Desmeules

"Carbon addition in the oxide pelletizing process is a big concern at the Sidbec-Normines pelletizing plant since 1976.Laboratory pot-grate testing carried out before the initial start-up of the Port-Cartier plant indicated that the nominal pelletizing grate capacity could be increased by fifteen per cent with a suitable carbon addition. Also an improved induration cycle offered the possibility of a significant energy reduction within the process with no adverse effect on pellet quality. A one-month plant scale program duplicated the lab test results and confirmed the anticipated cost saving by using these techniques. Since March 1980, Sidbec-Normines used coke addition as a current operation.This paper reviews briefly earlier laboratory and in-plant test work carried out to investigate the effects of adding carbon materials to the Fire Lake hematite concentrate, and presents operation techniques and plant results of carbon addition in the Port -Cattier pellet plant.IntroductionThe Sidbec-Normines pelletizing plant at Port-Cartier, Quebec, is designed to produce six million ton s per year of oxide pellet s. It is a Dravo-built two-line plant; one line to produce three million s tons per year of blast furnace grade pellets averaging 5.5 per cent silica, and another line of three million ton s to produce direct reduction grade pellets of about 2.0 percent silica.The laboratory pot-grate test program was conducted in 1977 at the British Steel Corporation Research Laboratories in England, with the assistance of J .E. Appleby, consultant to British Steel Corporation (overseas services) Limited.The purpose of that test program was to determine the optimum energy saving cycle and to study the physical and metallurgical effects on blast furnace and direct reduction pellets."

Jan 1, 1983

By G. H. Montgomery

THE PROPERTY of Aunor Gold Mines, Limited, consists of eleven claims, located in Deloro township, approximately three miles southeast of the town of Timmins. Production began in 1940 and currently the mine is operating at a rate of 485 tons per day. GEOLOGY AND MINE DEVELOPMENT The ore zone at Aunor occurs in altered lavas bounded on either side by soft talc-chlorite schist, locally known as 'soapstone'. The zone has a strike of N.80°E, dips 60° North, and varies in width from 0 to 250 feet. Within this zone the main orebody has a westerly plunge, away from the No. 1 shaft area (Figure 1). The mine is developed by a vertical three-compartment shaft from surface to the 3,082-foot horizon. Working levels are spaced at 125- foot intervals from the 625-foot to the 1,625-foot horizon, from which to tl1e 2,125-foot level the interval is 250 feet.

Jan 1, 1957

By T. C. Murphy, W. Taciuk

In 1966, the Iron Ore Company of Canada commissioned a wet magnetic scavanging plant for the recovery of fine magnetite values p.resent in spiral tailings discharged from a spiral gravity separation process. The plant includes dewatering, grinding, classification, thickening, mini-wedge screening, and primary, secondary and tertiary wet magnetic separation stages. The source of feed varies in quantity and quality, so the original design included variable operational procedures to deal with these conditions.

Jan 1, 1972

By Bennett McLaughlin, Gille Brousseau, John F. Cook

"La Mine Bousquet commenced operations in October 1979. Mining has been by underground methods from two main zones which dip steeply to the south , Sub-level stoping methods with following fill are used.The orebody and immediate country rocks are sericitic and highly schistose. The intensity of schistosity varies significantly and poor ground conditions prevail, especially within the orebody,Initially few mining problems were encountered but in May 1981, significant damage occurred. A system of stabilizing pillars was introduced with improved support systems. Predevelopment in ore and pre-drilling of blastholes were reduced with extra footwall development.Damage has continued to occur on a regular basis particularly during the spring thaw. Generally, the adverse conditions have been successfully overcome.IntroductionMost of the mining problems that have been experienced at Bousquet have been caused by poor ground conditions . This pa per describes these conditions, considers the cause and describes the ways in which the conditions have been dealt with . Despite the problems, Bousquet is a successful operation which in 1983 produced 95,000 ozs of gold from 514,000 tons of ore."

Jan 1, 1985

By W. A. Bain

"AbstractProduction from the Excelsior Reservoir has amounted to approximately one million barrels. This production has caused a 'Pressure •drop of 10 p.s.i. from the original pressure of 1,245 p.s.i.g. Volumetric balance calculations indicate that the pool as being produced by a water drive whose strength is •probably unsurpassed in Western Canada. It has also been shown by 'unsteady state' calculations that the reservoir will still be above the saturation pressure of 915 p.s.i.g. at the time of depletion. The average permeability of the producing formation is approximately 1,000 millidarcys and, consequently, well draw-downs are very low. The field is essentially a bottom-water drive and calculations have shown that gravity drainage will greatly assist the recovery of oil. Water flooding data on several cores •have placed the flushing efficiency at •approximately 50 per cent, which indicates a recoverable oil-in-place of 17.7 million stock tank barrels. Calculations and field data indicate that the MER for the early life of this field is probably as high as 8,000 to 10,000 stock tank barrels per day.IntroductionTHE EXCELSIOR NISKU oil reservoir is located about twenty miles northeast of Edmonton. The field was discovered in November, 1949, by Imperial Excelsior N.o.1 well, in Lsd. 13, Sec. 3, Twp. 56, R. 22, W. 4, at a depth of 3,850 feet.Since discovery, development has continued on a 40~acre spacing pattern. At the end of 1951, drilling over approximately 80 per cent of the estimated productive area of 1,680 acres had established 32 we1ls capable •of production. The field •has been fairly well delineated by dry holes on all but the eastern flank ."

Jan 1, 1952

By Jacques Nantel

Mechanical-electrical personnel are present in all phases of the mining industry; the coverage is broad and diversified. Concepts of energy accounting are reviewed to pinpoint the sectors with a large energy consumption. Four sectors are reviewed: underground hard-rock mines, underground soft-rock mines, open-pit mines and mineral processing. In each sector, five or six technical innovations are analyzed as to their contribution to a more efficient use of energy.

Jan 1, 1979