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By D. Perednis

Fuel cells with thin samaria-doped ceria (SDC) electrolyte films deposited onto an anode support using spray pyrolysis were fabricated. The SDC films were deposited onto porous NiO-YSZ substrates at deposition temperatures between 400°C and 450°C. The influence of process parameters such as deposition temperature, flow rate, type of salt and salt concentration on the quality of the film was studied. A smooth dense film was successfully deposited using the precursor cerium ammonium nitrate and samarium nitrate dissolved in butyl carbitol (33.3 vol.%), 2-methoxy-l-propanol (33.3 vol.%), and ethanol (33.3 vol.%) solvent mixture. A deposition rate of 125 nm/h was achieved.

Jan 1, 2005

By P. J. Urso

"The coal reserves of the Crow's Nest Basin in British Columbia have been known since the late 1860's. The 51.0-million-long-ton (over 15 years) sale of low-volatile coking coal to Japanese steel mills, as finalized in 1968, establishes the importance of these coal reserves in the world markets.In the early stages of the exploration program, which began in January, 1967, emphasis was placed on deter-mining the reserve of underground low-pitch coal within the No. 10 or Balmer seam of the Kootenay coal forma-tion. The finding of low-cover reserves in excess of 100,000,000 tons altered the initially planned underground program. Extensive tests were performed, establishing the excellent coking characteristics of the open-cast Balmer coal. Due recognition was given to the ultimate reclamation costs of mined lands and associated spoil areas.t was determined that, to achieve the costs desired, a high productivity was necessary, requiring large mining equipment. Operating criteria were set out, based on producing 4.2 million tons of clean coal per year. To optimize recovery, the preparation plant feed size was fixed at Yi in. x 0. The initial basic design capacity of the plant was 1,000 tph. The washing plant is composed essentially of four separate cleaning sections: a dedusting section; a multi-stage heavy media cyclone section; water cyclones; and flotation cells. Subsequent to the basic program, additional sales were made of 6.0 million long tons over the initial three-year period and the plant capacity was raised to 1,400 tph through the addition of a 400-tph coarse-coal treatment section. All wet coal products from the fine coal plant will be dried in a 70-tph (water) heat dryer. A unit-train concept of coal transportation between the mine site and the Westward Terminals at Roberts Bank has been negotiated with the Canadian Pacific Railroad. Facilities at the port will include a 4,000-tph rotary car bumper, 400,000-ton clean-coal stockpiles, and a bucket reclaiming system having a total ship-loading capacity of 6,000 tph."

Jan 1, 1969

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989

By G. E. Viens, R. A. Campbell, G. N. Banks

A survey of the literature reveals wide differences in the procedures used in making iron ore pellets and in the properties of the pellets obtained. In this paper, the methods of production and the properties of pellets, as reported in the literature, are examined in an effort to determine what correlations exist between them. An attempt is also made to determine the levels of the properties of pellets which are considered acceptable and desirable in modern practice. M UCH has been written regarding the important changes which have been taking place recently in the iron ore industry. As the demand for ore has increased and the supply of direct-shipping ore has dwindled, tl1e problems associated with the utilization of lower grade ores ha\•e been intensely investigated and important advances in both beneficiation and agglomeration techniques have taken place. In particular, there has been a great deal of activity in connection with the pelletizing method of agglomeration. The superiority of pellets over raw ore has been demonstrated in blast furnace tests

Jan 1, 1962

By N. Melnyk

"FOREWORDThis paper provides a unique description of a method devised for mining a very thick steeply dipping seam of soft gassy coal which was prone to spontaneous combustion. The editors con¬sider that the information in this paper should be important to those who may have to consider mining such seams again at some time in the future and therefore believe that the paper warrants reprinting in the present volume. The author was ask¬ed to review the paper and to add any additional relevant in¬formation. He provided the accompanying footnote, only a month before his death on April 22, 1982.IntroductionIn the past, the Cadomin Coal Company has opened four mines, all in the same coal seam or its folds. Three of these were opened from river level by horizontal entries or rock tunnels. and the fourth, the present working mine, by vertical shafts. This paper deals largely with some operating phases of this fourth mine, with which the writer has been associated.The seam worked here is a thick, steep, bituminous seam, and the writer feels there is a paucity of published data on the mining of such seams. Possible reasons for this are that such seams do not lend themselves to intensive development or mining, there is little chance to mechanize because of the extreme pitch, and operations are fraught with many problems. In addition the present operations in this particular' seam are being carried on at a level below the former workings, introducing new problems, not encountered on the upper level.Coal will, without question, long continue to be an impor¬tant factor in the national economy, and some of the best coal is to be found in thick, steep seams. But with the exhaustion of the easily-mined coal near the outcrops, future coal will have to come more and more from lower levels. At Cadomin there is still considerable coal on the second level, below the old river-workings, and there is a possibility that, in the future, still lower levels will be worked. It is the purpose of this paper to indicate some phases of such lower-level operations and to invite discussion."

Jan 1, 1985

By S. Sillitoe

In mining, as in other business and engineering enterprises, efficient operation depends upon how well and how quickly the lines of communication can function. Mines have used the telephone on and between levels for many years, but in the hoisting shaft maintenance of physical wire connections for communication with the moving cage or skip has been found, for all practical purposes, impossible. A most natural solution was, therefore, the code-bell or buzzer signal system between fixed levels, and this has been standard practice throughout the mining world for many years. However, this system has serious limitations which make it impossible to signal a cage between levels in the shaft, and it requires crude, hazardous or costly methods for signalling during daily shaft inspection. Radio signalling overcomes these difficulties, because the communication medium is never broken and the cage-tender or shaft inspector can safely signal to, and receive signals from, the hoistman at any time from any position in the shaft, whether stationary or in motion. In addition to both audible and visual code signalling, two-way telephone communication and slack cable alarm are facilities made possible in recent commercially developed equipment.

Jan 1, 1949

By M. Kolahdoozan, H. Noori

"Molybdenite flotation at the Sarcheshmeh Copper Complex has been studied as a function of pulp potential controlled using two types of sodium sulfide (mineral and chemical origin). Air and either plant or laboratory nitrogen was used as a flotation carrier. Potential measurements were taken in the rougher cells as it was proved to be vital for molybdenite flotation. Flotation test with reducing potentials between -525 and -575 mv gave the highest molybdenum recovery (93%) and the lowest copper recovery of between 4 to 15% can be achieved. These potentials did not change considerably by adding increasing amounts of sodium sulfide. At more oxidizing potentials, i.e. more than -450 mv, the recovery of copper increases while the recovery of Molybdenite drops.INTRODUCTIONThe average copper ore feed grade to the Sarcheshmeh flotation circuit is typically set at about 1.2% Cu. to be delivered to processing unit is set at 1.2%. There is no control of molybdenum (Mo) which usually varies between 0.01 and 0.04%. During concentration, a Cu-Mo concentrate is produced by one stage of roughing, one stage of scavenging and two stages of cleaning. Final concentrate contains 0.5% of Mo and 32% of Cu while the particle size is 90% under 42 microns (325 mesh). Because of the high grade of Mo in this concentrate and economic interests, a molybdenite flotation circuit plant was built in 1984. This plant was designed to treat 1432 tons of Cu-Mo concentrate (on dry basis) and consists of one stage of roughing followed by seven stages of cleaning. After dewatering the concentrate contains 53.7% Mo which is dried and shipped overseas.The majority of molybdenite production worldwide comes as byproduct of copper porphyry ores. The Mo grade typically varies between 0.01 and 0.06% and accompanies chalcopyrite and chalcocite. Due to the hydrophobic nature of molybdenite, it can be floated along with copper sulfides. Thus the overall concentrate of Cu and Mo contains 0.2-1% of molybdenum as well as 20-42% of copper. To separate the Mo, Cu and Fe minerals, depressants are used. The most important of which are sodium sulfide, sodium hydrosulfide, Anomal D, sodium cyanide, ferropottasium and ferro-cyanide. The first three regeants have been extensively used for successfully treating porphyry ores [1]. In the molybdenum plant of the Sarcheshmeh Copper Complex only sodium sulfide has been used to date."

Jan 1, 2006

By A. G. Doll

"Multi-stage crushing plants, including high pressure grinding roll (HPGR) circuits, require more materials handling equipment than SAG and ball mill circuits. A temptation exists to neglect the energy consumption of materials handling when doing desktop comparisons of HPGR versus SAG milling circuits because estimation of materials handling power requirements can demand significant general arrangement drafting that is not available when performing preliminary scoping or ""desktop"" studies.The largest component of materials handling power is consumed by conveyors when lifting material between stages of crushing, meaning that a simple potential energy model can be used to evaluate conveying specific power consumption. This potential energy consumption for conveying can then be factored to provide overall materials handling specific energy consumption suitable for desktop studies of HPGR and other multi-stage crushing circuits. The technique also permits different crushing circuit flowsheets to be evaluated, at a preliminary level, by simply counting the number of times a conveyor must ""lift"" ore from ground level up to a bin or other equipment mounted up high.INTRODUCTIONTrade-off studies of multi-stage crushing plants involving high pressure grinding rolls (HPGRs) versus semi-autogenous grinding (SAG) mill circuits typically focus on the operating cost savings of crushing plants versus the capital cost savings of SAG mill plants. Very high-level (or desktop) studies of this type do not include a great deal of engineering work, meaning that the details (and costs) of ancillary systems are often not captured when doing the comparisons. The more complicated nature of the multistage crushing plants means there are more ancillary systems than a SAG mill plant, risking a skewed analysis of the operating costs, benefiting the HPGR option.One of the ancillary systems that may be overlooked is the more complicated conveying systems inherent in multi-stage crushing plants. Due to the mass of material being handled in large mining operations, these conveyors become a significant portion of the operating costs. A simple way to estimate the specific energy consumption of conveying systems without requiring engineering drawings and a site layout would allow high-level studies to capture this operating cost."

Jan 1, 2015

By D. C. Fraser

Copper occurs invisibly in a geo-logical environment characterized by swampy conditions and an accumulation of forest peat. This swamp, located in southeastern New Brunswick, contains up to ten per cent cop-per (dry weight), in the organic sediments. This occurrence appears unique in that the metal is apparently organically combined in a chelate compound. Unlike the acidic nature of most peat bogs, the pH of the cup-riferous peat is nearly neutral. Analyses of the peat and associated soils have indicated that the bulk of the copper is contained in the organic sediments. It appears that the cop-per distribution is affected by capillarity, evaporation and the growth of frost crystals, and that the copper fixation is effected by organic sequestration resulting in the metal being bound to the nitrogen or oxygen components of the forest peat. While such a fixation mechanism is not definitely established as responsible for the immobilization of the metal, the facts at hand are compatible with

Jan 1, 1961

By R. J. Craig

Introduction All mining operations produce rock dust. Inhalation of rock dust, particularly if it has a high silica content, causes silicosis. Silicosis is, therefore, recognized as a hazard of the mining industry and has been made compensable throughout most of Canada. Most of the dust in any mining operation is caused by rock drilling and blasting operations and the movement and transportation of broken rock. Dust from blasting cannot be eliminated, but it can be controlled by means of increased ventilation, the use of water sprays, and the control of blasting hours. Dust from ore movement can be reduced by keeping the broken rock in a moist condition at all times. The dust from the rock drilling operation has been found to be the most difficult to control. Concentrations of dust caused by rock drills in stopes can usually be reduced to the safe minimum of 300 particles per cubic centimeter (p.p.c.c.) by diluting the air with increased ventilation. In development headings, where the machines are more confined, this is not always practicable. Therefore, the dust must be eliminated at its source. This paper deals with the reduction of dust from Leyner machines by adopting improved designs.

Jan 1, 1947

By M. Dupuis

It has been previously demonstrated [1,2] that using selective collector bar rodding has a big impact on the uniformity of the current density at the top surface of the cathode block and hence on the intensity of the horizontal current in the metal pad, The present study investigates the impact of using selective collector bar rodding on the MHD stability of a 500 kA aluminium electrolysis cell, For this purpose the recently developed MHD package for the aluminium reduction cell time dependent behavior is used.

Jan 1, 2005

By H. Yoshida, H. Hatta, T. Suzuki

"The effect of the copper and magnesium contents and quenching rate during quenching on the age hardening behavior of 2000 series aluminum alloys was investigated. For the higher copper-containing specimens as conventional alloys, like AA2024, precipitation of the stable phases increased as the quenching rate decreased under the as-quenched conditions. The maximum hardness after the artificial aging of air cooled(AC) specimens was much lower than that of the water quenched(WQ)specimens. On the other hand, for the lower copper-containing specimens, coarse precipitation did not increase even in the case of the AC. The age hardening behaviors of the WQ and AC were very similar such that the maximum hardness and aging rate were almost the same. Many parts of the fine precipitates that increased the hardness were thought to be the GPB zone or fine S’ phase for the WQ and relatively coarse S’ phase for the AC. From the calculated CCT(continuous cooling transformation)diagrams, the lower copper-containing specimens could maintain the copper and magnesium in the solid solution state during the AC, so they could be quenched at a rather slower quenching rate like the AC.INTRODUCTIONThe 2000 series aluminum alloys, containing copper and magnesium as the major chemical components, are some of the well-known heat treatable aluminum alloys. These alloys have a high quenching sensitivity, thus the age hardening ability of these alloys decreases with as low quenching rate. To prevent the decrease of the age hardening ability, quenching is done by a method such as water quenching, which is not very efficient in an industrial situation, because the method requires such large equipment. For these alloys, reducing the quenching sensitivity helps them to be produced in a rather convenient way. For example, 6000 series alloys such as A6063 have low quenching sensitivity, thus they could be quenched by only air cooling just after extrusion and they do not need water quenching. Based on these reasons, investigations of these alloys with high copper and magnesium contents have been conducted in the past to find a way to lower the quenching sensitivity by adding transition elements such as manganese, chromium and zirconium (Kanno, Suzuki, & Itoh, 1986; Suzuki & Itoh, 1986; Kanno, Sakuma, Muromachi, & Watanabe, 1988). However, very few studies have focused on the quenching sensitivity of the lower copper and magnesium containing alloys because of their usage for structural components with high strength, and most of the past studies have used only the fast quenching method like water quenching. On the other hand, from our recent results, there is a possibility to lower the quenching sensitivity of 2000 series alloys with lower alloying elements. In this paper, the effect of the copper and magnesium contents with lower alloying elements and quenching rate, especially in case of slower quenching rate than conventional quenching method, on the age hardening behavior of the 2000 series alloys is investigated by the hardness measurement, structure observation and thermal analysis."

Jan 1, 2018

By W. J. S. Craigen, G. E. Wittur

"In the context of today's continuously changing world, there are many factors which must be considered when attempting to assess the ability of Canada's primary copper producers to remain competitive in the face of increasing competition in world markets. In this paper, we have attempted to document those factors that will have the greatest impact on the future viability of Canada's copper industry, and to suggest possible strategies to fully utilize whatever inherent advantages Canada may have to enhance its competitive position. Technological factors related to the efficiency of precious and by-product metals recovery, energy type and utilization efficiency, production and sale of sulphur by-products, and control of 502 emissions are given high priority in this evaluation of Canada's future needs to remain competitive. Particular emphasis is placed on assessing the relative viability of hydrometallurgical versus pyrometallurgical processes for copper; to address uniquely Canadian conditions and problems. Due consideration is also given to the economic incentives required to allow Canada's copper producers to compete under anticipated world market conditions and to facilitate the continued development of Canada's copper resources. IntroductionWhen we try to assess the viability or competitiveness of any industry the bottom line is still usually, ""Can we produce a pound of product cheaper than the competition?"" Canada's copper industry is certainly no exception. However, as with most resource-based industries dependent upon exports, there are many factors which have a significant effect on the cost components which make up the total cost of producing and selling a pound of copper. It is desirable therefore to have as clear a picture as possible of the cost components, the major factors affecting them, and how they compare with the competition, particularly the third-world copper producers.In this paper we have attempted to provide a brief outlook for world copper markets and a brief overview of Canada's competitive position. We have also attempted to document those factors which will have the greatest impact on future production costs, and have suggested possible initiatives to utilize inherent Canadian advantages to enhance our competitive position. Special emphasis has been placed on technological initiatives designed to make full use of these ""advantages"", to develop superior beneficiation and extraction! refining technologies. Major factors considered in the present study are:"

Jan 1, 1986

By A. Pearson, Auld. F. A., S. O. Colbeck

"To minimise mine shaft maintenance over the long-term, some potash mine shaft sinking projects have required the provision of a continuous fully welded waterproof steel liner over a substantial depth to achieve zero water ingress. This brings many challenges, including the implementation of a bottom-up construction sequence incorporating extensive waterproof welding and how to ensure the integrity of the welded liner when subject to substantial temperature fluctuations that are likely to occur with a composite steel-concrete liner placed within an artificially frozen shaft excavation. This paper highlights the key challenges and discusses multiple mitigation measures including vertical shaft movement joints and a combined structural-thermal analysis approach. INTRODUCTION Whilst the application of combined steel and concrete shaft liners using a fully welded steel liner is not new and has been used in several previous projects, most notably at Lanigan (Storck, 1968 & Roesner, 1980), recently the need to provide a continuously welded steel waterproof liner for over 800 m length of shaft for a potash mine has been considered. The need for a fully continuous welded steel liner arises from the perceived benefits of providing a fully dry shaft environment to; increase the life expectancy of the shaft; reduce routine maintenance particularly combatting salt accretion and minimising wash down practices; and improve long-term ground stability by preventing salt dissolution. Whereas previous projects have employed discontinuous sections of steel liner, when a fully continuous liner is employed longitudinal shaft strains from thermal changes result in significant deformations that must be either explicitly accommodated or resisted. Note, these thermal vertical expansion forces are more than capable of lifting the shaft collar and head frame structures should they be fixed in place. Typically, shafts are designed to resist vertical forces (collar loads and self-weight) by creating mechanical interlock with the adjacent ground. In competent rock this occurs incrementally with the construction of the shaft liner, and occasional hitch/crib structures are constructed as intermediate foundations to guarantee the transfer of vertical forces at distinct horizons. Usually this means cribs are constructed at first rock head, above the station level, and at the sump, although sometimes additional cribs are formed when entering and exiting weak strata or when a change in shaft liner construction is required."

Jan 1, 2019

By W. R. Tyson

Pipelines for the transport of gas and oil are being designed to operate at increasing pressures in increasingly harsh environments. The steel used to construct these pipelines must have adequate toughness to tolerate weld imperfections (i.e. withstand bending strains) and to arrest running cracks (i.e. to prevent propagation of axial fractures). The problems posed in specifying suitable toughness parameters and the approaches currently being used to measure them are discussed.

Jan 1, 2005

By James Pirie

"The major Archean gold deposits in the Red Lake greenstone belt, which have produced over 374 million grams of gold since 1930, occur near the top of the lower komatiitic to tholeiitic mafic to ultramafic metavolcanic sequence. The upper calc-alkalic mafic to felsic rocks form three discrete and separate ediftces overlymg this lower sequence.The gold deposits are classified according to their stratigraphic or lithologic associations into:1) mafic-volcanic-hosted deposits;2) felsic-intrusive-hosted deposits; and3) stratabound deposits.Group 1 and to a lesser extent Group 2 deposits occur within zones of alteration several square kilometres in extent. The nature of this pervasive alteration can be characterized by comparison of petrochemical data from the altered rocks and their fresher equivalents some distance away. The altered rocks have substantial addition of SiO2> CO2, K2O, As and Sb and subtraction of Na20, CaO, MgO and total Fe. Cr, Ni, Co and Zr appear to have been relatively immobile. Hydrothermal alteration and gold deposition probably accompanied early fumarolic activity and continued during subsequent deformation the metavolcanic sequence, with gold eventually being mobtltzed and concentrated into major vein structures to form the present orebodies. The smaller Group 2 deposits formed by emplacement of felsic intrusions into already altered, anomalously gold-bearing mafic metavolcanics, with the heat from the intrusions setting up parasitic hydrothermal systems which mobilized the gold and deposited it along with minor sulphides in fractures in the cooling intrusions."

Jan 1, 1982

By B. C. Jago, H. Derbuch

"The Freightrain kimberlite is located on the Brodeur Peninsula, Baffin Island, Nunavut. Twin Mining is exploring the pipe and adjacent land (79 claims/655 km2) using a combination of airborne geophysics, soil sampling, diamond drilling, trenching and bulk sample processing. The pipe originally was discovered by Cominco Limited in 1975, re-evaluated in 1993 by Lumina Investment Corporation, when it was staked as the Zulu pipe, and subsequently covered by three claims in 1998 by Helix Resources who called it Freightrain.The Freightrain pipe coincides with a strong, ovoid-shaped aeromagnetic anomaly. It is the only surface exposure of kimberlite within a 30 km long linear trend of fourteen aeromagnetic anomalies that are up to 600 m in diameter.The pipe is exposed in the crater facies, near the transition into diatreme facies as indicated by the occurrence of pyroclastic kimberlite characterized by abundant olivine macrocrysts, juvenile lapilli and kimberlite autoliths set in a serpentine-calcite matrix. Olivine, Cr-pyrope garnet and chromite are the most abundant macrocrysts; clinopyroxene, ilmenite and phlogopite mica occur in minor to trace amounts. Garnet and chromite harzburgite, garnet lherzolite, garnet-spinel lherzolite and rare eclogite dominate the xenolith population.Garnet and chromite mineral chemistry indicate encouraging diamond prospectivity and that potentially diamondiferous garnet and chromite harzburgite were the principal sources of diamond in the mantle at the time of kimberlite eruption.Single clinopyroxene grains define an ~42 mW/m2 sub-continental geotherm that is rooted in the diamond stability field. This compares to a slightly hotter geotherm (~48 mW/m2) for adjacent Somerset Island kimberlites with an origin in the graphite stability field. This data accords with the general lack of sub-calcic Cr-pyrope garnet, diamond inclusion chromite and diamond in Somerset Island kimberlites."

Jan 1, 2002

By Marc C. Bétournay

A mine production locomotive, the world?s first applied industrial fuelcell vehicle, has been designed and tested in the context of a number of proof-of-concept projects supported by the Fuelcell Propulsion Institute, an international consortium of stakeholders dedicated to facilitate the commercialization of fuelcell vehicles. The locomotive?s simple electric-powered motor and controller system was ideal to study a number of requirements related to fuelcell power application: hydrogen power plant operation, underground hydrogen use, risk and regulatory requirements, production performance versus the conventional battery-powered locomotive version under measured duty cycles and production requirements, power plant design improvements for other fuelcell vehicles, and cost-benefit aspects. This article will focus on the design and testing aspects of this project which has led to successful performance demonstrations of the vehicle under surface and underground conditions at two mines. It will also present information on the creation of a safe, reliable and efficient power plant which fulfilled its design objectives, including longer productivity time for a given vehicle fill-up.

May 1, 2003

By T. I. Urbancic, C-I. Trifu

"ABSTRACTSeveral case studies are presented on the use of seismic techniques to map active structures, evaluate changes in stress levels, and identify the conditions leading to large magnitude seismic events and the generation of rock-bursts in Canadian mines. The results suggest that microseismicity can be used to identify the orientation of active fractures; define regions of relatively high and low stress, and those most likely to host a rockburst; determine the role of local stress on observed shear failures; and identify the path of stress transfer associated with the remote triggering of rockbursts. Additionally, the conditions leading to rock-bursts can be characterized by a significant increase in the clustering of microseismic events along the fault plane orientation of an impending event, and an increase in the effective stress levels. It is concluded that the analysis of microseismicity provides the means for remotely monitoring rock mass behaviour as a result of mining."

Jan 1, 1997

By D Maschemeyer

The cobalt production of the Chemical Metallurgical Division of Sherritt Gordon Mines Limited was supplemented, from May, 1962, to June, 1964, by processing 3,500 tons of a calcined cobalt-nickel concentrate. This paper describes the reduction roast -aqueous sulphuric acid leach process and the operating practices employed in recovering cobalt, nickel and copper from this oxidized by-product of a lead-copper operation. Incorporated in this paper is a description of how this process was integrated with the existing ammonia leach -hydrogen reduction process for the recovery of nickel and with the soluble cobaltic ammine process for the recovery of cobalt. Introduction T HE Chemical Metallurgical Division of Sherritt Gordon Mines Limited at Fort Saskatchewan, Alberta, has recently completed ten years of operation utilizing the ammonia leach process for the recovery of nickel, cobalt and copper from sulphide concentrates, matte and other materials amenable to this process. A continuing development program, along with the expansion of certain facilities, has enabled the refinery to attain a production rate of 31, 000,-000 pounds of nickel per year by hydrogen reduction. This represents an increase of approximately 85 per cent over the original design capacity of the plant.

Jan 1, 1965