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By H. W. Wevers

Fatigue failure and accompanying brittle failure occurs frequently in heavy mining equipment. This paper discusses how fracture mechanics can be applied as a tool for crack control and crack management. Information is provided to determine if particular components are prone to brittle failure. By using existing fracture mechanics formulae, an estimation of the critical crack size can then be made. It is explained that for a successful application of fracture mechanics, both the actual engineering stress in the component and the mechanical properties of the applied material must be known. The importance of toughness at low temperatures is quantitatively illustrated by calculating critical crack sizes at room temperature and at below-zero temperatures. Understanding the possibilities of fracture mechanics will also produce a climate in which the purchaser of equipment can more precisely analyze the relative quality of components with respect to crack tolerance and failure prevention. In this manner, communication between the user and manufacturer of equipment may also become more precise and effective, leading to improved design.

Jan 1, 1977

By Wm. D. Jr. Sheldon

THIS paper presents practical data to aid in the selection of a mine ventilating fan, and outlines considerations to be made to ensure satisfactory operation and optimum efficiency of the fan. Much has been published on the general subject of mine ventilation, but the writer has found few specific data on factors and considerations which govern the selection of a fan-data which should be available to the operator if his fan is to give satisfactory service within the range of the high-efficiency portion of its performance curve and deliver the specified air capacity when operating against the anticipated range of resistance of the mine. The total quantity of fresh air furnished by the ventilation system must be adequate to provide, and to ensure at all times, safe and healthful working conditions in the mine. It is assumed that the mine operator is able to determine the air quantities required for the various parts of the mine.

Jan 1, 1941

By K. T. Audt

The Yayoi period, from about 300 B.C. to A.O. 300, represents a time of important changes in Japanese history. During this period the advanced rice culture of the Asian continent was introduced to Japan, along with the techniques of animal husbandry, spinning, bronze casting and metal working(1) . As was the case in the Jomon period (11000 B.C. to 300 B.C.), the Yayoi period is traditionally defined by a particular type of pottery, characterized by the use of the potter's wheel and an extreme simplicity of decoration and form(2) . Pieces of this pottery were found in 1884 in a district of Tokyo, known as Yayoi-Cho, not far from Tokyo University. Within a decade the name Yayoi had come to be used for the period which also saw the first casting of metals in Japan121. During the Yayoi period, the foundation of the ancient Japanese state was laid as the individual small communities were unified and as labour specialization and social levels developed. In fact, the Yayoi may be the true ancestral culture of Japan(3) . However, the origin of the Yayoi is not definitely known. One theory indicates that the Yayoi people may have been driven from the Asian mainland (via Korea) by the dynastic wars that accompanied the unification of China under the Ch'in and Han and that these settlers rapidly displaced the Jomon. Bronze objects and the cultivation of rice may have arrived about the same time - in the third century B.C. Iron was in Japan within another century, but since it rusts badly and disintegrates, only a few small pieces are known from such an early date(4) . After about 50 B.C., the Yayoi cultures of western Japan were in fairly close and regular contact with the continent via Korea(5)

Jan 1, 1999

By R. Bashir, J. F. Hatley

ABSTRACT Northern Saskatchewan boasts some of the world’s largest known high-grade uranium deposits. The successful mining of these deposits cannot be accomplished without overcoming technical challenges, however, which include high grade of the uranium ore, specialized mining methods to deal with groundwater at high pressures, and poor ground conditions. This paper discusses the various mechanisms of inflows at three of Cameco Corporation’s sites in northern Saskatchewan. The risk of inflows is quantified in terms of unique challenges due to hydrogeological conditions, rock mass integrity, and uncertainty in geological conditions. Strategies in the case of an inflow are also briefly described.

Jan 1, 2013

By O. A. Ojo, E. Anisimov, A. K. Khan

Electro-spark deposition (ESD) has recently generated a great deal of interest in processing aerospace materials. This is due to its potential for joining and repairing difficult-to-weld precipitation strengthened nickel-based superalloys without having problems of welding cracking that often plaque these materials. The short duration of current pulses involved in the process combined with the intermittent contact results in extremely rapid thermal cycle that produces nearly no heat affected zone in the substrate material. The microstructure of electro-spark deposited superalloy was meticulously studied in this work by scanning electron microscopy (SEM) and analytical transmission electron microscopy (TEM). The results show that in contrast to general assumption, the extreme rapid cooling rates involved in the ESD process did not produce partition-less solidification that is devoid of second phase microconstituents in the material. The secondary microconstituents were found formed along the intercellular regions of the solidification microstructure. The nature of these particles and the possible implication of their formation on mechanical properties of ESD processed material are reported and discussed.

Jan 1, 2015

By C. E. Smith, R. J. Inglis, M. I. Brittan, J. H. Schoeman

"AbstractA number of plant-scale cyanidation tests were carried out in an attempt to uncover the causes of fluctuations in gold recovery efficiency. Computer analysis of the results verified that the treatment of reclaimed waste rock material along with normal run-of-mine ore was having an adverse effect on metallurgical efficiency. Mineralogical examinations showed that the free gold particles in the dump material were heavily tarnished or coated (predominantly by hydrated iron oxide), accounting for the lower recoveries. The indications were that the effect could be counteracted somewhat by using higher than normal cyanide and lime reagent concentrations and adequate leaching times. Analysis of the results showed further that leach pulp density was an important operating parameter affecting extraction efficiency. A variable activation energy leaching model provided an extremely good characterization of individual batch leach runs.IntroductionFLUCTUATING METALLURGICAL EFFICIENCY at the gold concentrator of the S.A. Land and Exploration Company Limited (""Sallies"") prompted some plant-scale cyanide leach studies in an endeavour to uncover the causes of the variations in gold recovery."

Jan 1, 1977

By D. R. E. Whitmore, J. M. Harrison

There are five logical stages in the search for orebodies in virgin territory, namely: (1) reconnaissance inventory of geology, and related investigations; (2) development of broad concepts as a basis for selecting regions of potential mineral deposits; (3) assessment of criteria leading to specific localities within these regions; (4) geo-physical and geochemical studies that will delineate small anomalous areas; and (5) stripping, drilling or other means of locating ore. In addition, the development of new means of extracting mineral resources and the finding of new uses play a vital role in our mineral industry. The continued growth of this industry will be largely governed by our ability to develop or to adapt new concepts and techniques, and to produce a greater number of scientists and engineers. It should always be remembered that more than one-third of Canada's exports are dependent upon our ability to find, develop and economic-ally exploit new orebodies.

Jan 1, 1967

By Lorne Roberts

"This paper describes: how Falconbridge's fire protection system meets the needs of the Lockerby Mine; why the system was chosen over other alternatives; how it is unique, but can be applied to any underground situation; details of the system; how it was installed; the role of a fire protection company; and general considerations when choosing afire-suppresant system.IntroductionIn May 1981, after about three years of searching for the best fire protection system for the re-opened Lockerby nickel mine at Whitefish, near Sudbury, Ontario, Falconbridge Nickel Mines Ltd. installed an AFFF type of fire suppression system. It was designed and supplied by the Fire Protection Systems Division of Levitt -Safety Ltd.The system protects against loss of life, equipment and/or production, and it complies with legislation should fire occur in a fuel storage area and/or scooptram garage and service bay at any or all of the three levels near Shaft No.2.About 18 months after Levitt-Safety began working with Falconbridge, the system was designed and installed at a cost considerably less than that which would be incurred if fire damage caused the loss of two days of production.The fire protection system, which overcomes a limited water supply, is a self-contained balanced pressure proportioning system. It senses the flow and automatically determines the correct concentration of foam to water. It is triggered by a release mechanism which operates a bank of nitrogen cylinders, which in turn pressurize a pressure vessel to expel the foam concentrate and water from the tanks. This solution is piped to sprinkler heads in the specific area."

Jan 1, 1982

By G. S. Hume

Introduction Core drilling of the bituminous sands of northern Alberta has been carried on by the Mines and Geology Branch, Department of Mines and Resources, under the supervision of the Director, W. B. Timm. This was part of the Dominion Government's wartime investigations, which included an agreement with Abasand Oils, Limited, for the study of commercial possibilities of obtaining oil from the bituminous sands. The drilling programme, commenced in 1942 by the Consolidated Mining and Smelting Company of Canada, was continued in 1943 and subsequently by Boyles Bros. under contract with the Mines and Geology Branch. Several areas have been investigated and one of these, the Mildred-Ruth Lakes area, ' herein described, is of special importance in that it contains a sufficiently rich and large deposit of bituminous sands and bitumen beds to warrant consideration of commercial developments for the production of oil. The Steepbank Area, East Side of Athabaska River The Steepbank area, on the east side of Athabaska river in township 92, about twenty-two miles north of Fort McMurray, was selected for drilling in 1942 because previous investigations by Ells indicated it was one of considerable promise both from the standpoint of having reasonably rich bituminous sands under relatively light overburden and also having an excellent tailing disposal and plant site for large-scale operations in proximity to Athabaska river. The drilling done in 1942 and 1943 was largely exploratory, and, when it was found that the southerly part of township 92 had only low-grade material, closer drilling was done in 1944-45 in the richer, more northerly part.

Jan 1, 1947

By J. M. Janssens, Van Quach Tinh, M. Ruel, R. Leblanc

"Microscopic studies of peat moss indicate a highly porous material. In view of using this natural product as an adsorbing agent for the treatment of polluted water, studies of its adsorbing power for beef extract and alkyl benzene sulphonate solution were determined. The effects of time of contact, particle size, concentration of adsorbent and concentration of pollutant were studied. In the case of beef extract, there is a COD reduction of around 27 per cent; in the case of the alkyl benzene sulphonate, the percentage reduction varied from 72 to 95 per cent. A water treatment plant based on the adsorbing power of peat moss with simultaneous recuperation of the pollutant is proposed."

Jan 1, 1971

By F. Channier

The paper provides the most recent information on the construction of the AP60 phase 1 plant of Jonquiere which is due to be commissioned and started up in the first quarter of 2013. HSE management on site by RTA, and cooperation with local equipment manufacturers and contractors of the Saguenay-Lac Saint Jean region are highlighted in this section. The AP60 phase 1 Jonquiere plant aims to demonstrate of the AP60 technology at an industrial scale and allows the further developments of the AP60 cell. The advantages of the AP60 cell technology in terms of productivity, power consumption and environmental footprint are also briefly presented in the paper.

Jan 1, 2011

By Allan F. Lawrence

"I AM SURE you do not expect from me any learned dissertation on the problems and opportunities of the mining industry. Y our program committee must have recognized my limitations when issuing the invitation to speak to you, because they very thoughtfully left the subject wide open.With the leeway thus granted, I hope that you will bear with me for a few minutes while I try to clarify the impressions of the mining industry that I have gained in the very short time I have held the Mines portfolio and some of the parts that government bas or should have in furthering its development.As I see it, it is the duty of the Mines Department, as an arm of the provincial government, to balance the proprietary rights of all the people against the interests to whom the privilege of developing our resources are, in a s e n s e, leased. To strike a fair balance is not always easy, nor is it possible always to satisfy both sides. Still, under the free enterprise democratie form of government to which I think we al! subscribe, no better way of handling the problem has yet been discovered."

Jan 1, 1968

By M. Nzotta, L. Teng, S. Seetharaman, A. Chychko

The objective of the present work is to optimize the EAF practice towards Mo alloying with maximum retention of the alloying element in molten steel. During Mo additions, there were significant losses to the dust (ca 7 %) and to the slag phase (ca 2 %), which had serious economic and environmental impacts. The present work was aimed at designing a suitable Mo precursor, an alternative to ferromolybdenum, as the Mo source and a process sequence for optimal retention of Mo in the steel. The design of the Mo source should be in such a way that low cost raw materials such as MoO3 concentrate have to be used, stable during the addition so that the vapour phase losses as MoO3 are kept minimum and the dissolution of the precursor in molten steel is easy without loss to the slag phase. After thermodynamic considerations, three precursor materials were chosen, viz. CaMoO4, MgMoO4 and Fe2MoO4. Synthetic mixtures of the component oxides in each case as well as pure MoO3 were investigated by TGA and high temperature XRD in order to find out the temperature range in which the compounds were formed. Experiments were also conducted separately where the evolved gases were analyzed. All the three precursors were formed easily and the loss of MoO3 to the vapour phase was found to be extremely low. Addition of the oxide mixtures to steel melts were conducted in three different scales, viz. 16 g, 500 g and 3 tons (induction furnacle). Initial experiments showed that MgMoO4 was not suitable since the Mo yield in the steel melt was not very high. Fe2MoO4 was found to perform best, the Mo yield reaching 98 %. Further trials were conducted in the 65 ton Electric Arc Furnace (EAF) at Uddeholms AB in Hagfors. Mixtures of mill scale, MoO3 and carbon in suitable proportions were added in a pre-determined addition sequence. It was found that, in the actual practice, the Mo yield reached 99 %, equaling in performance the addition of ferromolybdenum. The process offers an effective use of cheaper raw materials and very high Mo yield avoiding a pre-treatment step like the production of ferromolybdenum. This is both cost effective and environmentally advantageous. The process has been patented and is being currently implemented at Uddeholms AB, Hagfors, Sweden.

Jan 1, 2011

By H. Al-Kazzaz

The 2-mm butt joints of ZE41A-T5 sand castings were laser welded using 1.6 mm EZ33A-T5 filler wire and a continuous wave Nd:YAG system at a power of 4 kW, surface defocusing and various welding speeds, Compared with the base metal, the fusion zone showed significant grain refinement due to high cooling rate, No grain coarsening was observed in the heat affected zone (HAZ). The porosity area percentage and total solidification crack length in the fusion zone (FZ) were reduced as the welding speed increased from 4 to 7 m/min, Fusion zone area, total penetration depth, and weld width decreased with increased welding speed, The hardness in the FZ was similar to or higher than the base metal after a natural aging of about one year, but there was a drop in the hardness of the HAZ, The HAZ width decreased with increasing the welding speed, Tensile test showed that a joint efficiency of approximately 75 ? 90 % was obtained.

Jan 1, 2005

The Shortage of Mining and Metallurgical Engineers I N many parts of the Western World attention has recently been drawn to the acute shortage of mining and metallurgical engineers produced by the universities. Naturally, the reasons for this shortage have been discussed, and various remedies for it have been proposed. In this paper, I want to examine some of them. It is now fairly generally ac-cepted among mining men that the easy attractions of modern urban life have left the career of mining in the metaphorical as well as in the literal backwoods. The industry finds it increasingly difficult to recruit adventurous and intelligent young men; for such men now seek their intellectual, if not physical, adventure in more glamorous occupations from a safe social base in suburbia. The salaries, opportunities and security offered by the mining industry do not complete effectively with the rewards offered by other industries and by commerce, taking into account the social disadvantages of a mining life. The excitement and other non-material attractions of mining

Jan 1, 1965

By K. Hardy

As part of Inco's $115 million Fluid Bed Roaster SO2 Abatement Project, a new weak acid treatment plant (WATP) was constructed to treat bleed solutions from the Copper Cliff Smelting Complex gas-cleaning circuits. The WATP produces an iron-arsenic co-precipitate, termed "basic ferric arsenate" (BFA), which requires disposal in an environmentally acceptable manner. Following analysis of many potential options, the short-listed disposal alternatives were: A) Co-disposal of the BFA?gypsum sludge with rock tailings, a portion of which would be used in mine backfill, with the remainder being sent to the tailings area, and B) Co-disposal of BFA?gypsum sludge with pyrrhotite tailings in the tailings area. Testwork showed that the addition of BFA?gypsum sludge to mine backfill samples increased the uniaxial compressive strength (UCS) of the backfill for most samples, especially those at lower binder content ratios. Extensive analysis was conducted on samples taken from the Copper Cliff tailings area, where BFA?gypsum sludge from Inco's Copper Refining Electrowinning Department has been co-deposited with pyrrhotite tailings since 1990. Pore water samples from these areas contained very low arsenic concentrations, indicating that the arsenic had remained stable in that environment. Ultimately, co-deposition with pyrrhotite tailings was chosen as the preferred option for the disposal of BFA?gypsum sludge from Inco's new WATP.

Jan 1, 2006

By A Hitchen

A general outline is given for the determination of copper, nickel, cobalt, zinc, lead, cadmium, bismuth, manganese, uranium, molybdenum, vanadium, sulphate and fluoride by polarographic or amperometric methods in a variety of ores or metallurgical products. The detection of oxygen in gas mixtures by an amperometric method used as a safety device is also discussed. Introduction I N this paper, a general outline will be given of the polarographic and amperometric methods used for the chemical analysis of various ores and metallurgical products in the Chemical Analysis Section of the Extraction Metallurgy Division of the Mines Branch. The methods to be discussed will be confined to those based on the use of normal D.C. polarography and will not include those methods which utilize a cathode-ray, square wave, pulse or A.C. type of polarograph. For the sake of convenience, ? the polarographic methods will be discussed according to the type of supporting electrolyte employed, as the same electrolyte may serve to determine more than one element in more than one type of ore. Amperometric methods will be discussed according to the element to be determined rather than

Jan 1, 1965

By A. J. Sinclair, N. Champigny

"The Cinola gold deposit in the northern Queen Charlotte Islands, British Columbia, is in a clastic sequence consisting of a lower shale of the Late Cretaceous Haida Formation and an overlying interbedded sequence of pebble conglomerate and coarse-grained sandstone of the Middle Miocene Skonun Formation. Both formations are intruded by a stock and dykes of porphyritic rhyolite. Two K-Ar model ages indicate mineralization and probably porphyritic-rhyolite intrusion at about 14 Ma (middle Miocene). A splay of the Sandspit fault system constitutes the footwall on the west of the deposit.The Cinola deposit can be classed as Carlin-type based on features such as (1) small particle size for gold, (2) Tertiary age of mineralization, (3) element abundances (e.g. high Hg), (4) dominantly argillic alteration, (5) a structural setting associated with major faults, (6) porosity of the host rock and (7) spatial and possibly genetic association with felsic intrusions. Gold is widespread and occurs mainly as grains of< 0.5 11-m in silicified sedimentary rock, and in quartz veins. Locally, coarse > 100 11-m particles of native gold occur in quartz veins, especially in strongly brecciated porphyritic-rhyolite. Ore minerals are mainly pyrite and marcasite, but include small amounts of chalcopyrite, sphalerite, galena, pyrrhotite, cinnabar, tiemannite (HgSe), rutile, magnetite, hematite and limonite in addition to native gold and electrum. No silver minerals have been found; silver was found in gold particles in amounts varying from 6.2 to 24.2 weight per cent. Alteration products are sericite, illite, kaolinite and chlorite, with abundant quartz of several stages.The host rocks, specifically the Skonun Formation, formed as an alluvial plain facies in a braided river system discharging into a marine basin in early Middle Miocene time. During the Middle Miocene, this sequence was intruded by a rhyolitic stock. The highly porous and permeable Miocene clastic sequence apparently provided an optimum setting for the development of a large geothermal system, the energy for which probably derived from the rhyolite stock. Mineral deposition followed a well-defined paragenesis, which, from oldest to youngest, is: (1) precipitation of iron sulphide minerals, and early quartz; (2) several stqges of quartz veins, with deposition of sphalerite succeeded by galena, chalcopyrite and visible gold. Micron-size gold was precipitated throughout these two stages of mineral deposition. Argillitization of the host rocks probably in part coincided with the mineralization and continued during cooling of the geothermal cell.In-situ reserves have been estimated at 41.1 million metric tons averaging 1.85 g Au/tonne using a cutoff grade of0.86 g Au/ tonne."

Jan 1, 1982

This paper states how alloy and welding advances have made possible the rapid development of the use of aluminum in the construction of equipment for earth moving and off -highway rock hauling. The main details are given regarding the construction and field testing carried out on an aluminum prototype body. The test results of strain gauge readings are analysed, and a description is given of how these have been applied in subsequent designs. The increase in the number of aluminum units put into the various types of service in Canada, as well as the problems encountered, is described, and the experience gained from five years of field service is discussed in some detail. An assessment is also made of the durability of the e units. The economics of using aluminum, together with the current development position, are reviewed, and predictions are made for considerable future increases in the use of aluminum units in open-pit and off-highway operations.

Jan 1, 1964

By Jean-Pierre Côté, Alexandre Noiseux

"Hatch and ArcelorMittal Mines Canada have combined their expertise to develop a dynamic model of the latter’s Iron Ore Pellet Plant in Quebec, Canada. This model was used to predict the benefits of different expansion projects, as well as asses the best implementation sequence.Two modelling tools were used: a discrete-event simulation software used to develop the dynamic model of the Pellet Plant and an in-house process simulator. The latter was based on operational data and known behavior of the process, and was calibrated with historical data gathered under different operating conditions.The results of the process simulator were used as input values for the dynamic model, which included all of the operation steps of the pelletizing process, from concentrate beneficiation to baking of the pellets. The model has been validated by assessing its capacity to represent adequately the operation of the plant during a 20-month operating period. It was able to reproduce the plant capacity within a precision of 1.2%.Simulated “what-if” scenarios allowed quantifying the production increase associated with the addition of new equipment such as ball mills or balling discs, implemented individually or in combination. Results revealed a potential 10% increase in the annual plant production by adding additional equipment in the two most limiting sectors of the plant, grinding and agglomeration. The simulation results made it possible to quantify the synergistic effect of two projects on plant throughput; the model showed that the combination of two projects resulted in a greater production increase than the sum of the same projects evaluated individually.Now that it has proven reliable, the simulation tool can readily be used by ArcelorMittal Mines Canada process engineers to perform simulations for equipment optimization, and to evaluate the impact of various operating parameters such as equipment availability and tonnage, product mix or concentrate quality. This work showed that a reliable model can be developed based on known parameters in combination with the proper integration of the process knowledge."

Jan 1, 2010