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By J. G. Conaway, P. G. Killeen

"Gamma-ray spectral logging, a useful technique for uranium exploration and evaluation, has generally been underutilized by the Canadian mining industry. Provided that the technique is properly applied, it is capable of yielding reliable quantitative information regarding the distribution of uranium and other radioelements along the borehole under most conditions.In practice. there are numerous factors which potentially can degrade the quality of the log and thus any quantitative interpretation based on it. Fortunately, the appropriate choice of logging equipment and technique can avoid many such problems, and corrections can be applied to the data to compensate for most of the others."

Jan 1, 1980

By J. Jankovic

Numerous advantages have been recognized for solid oxide fuel cells (SOFCs) operating at temperatures of 500-700°C. However, there are several issues related to low temperature SOFCs, such as high electrolyte resistance and high electrode polarization. One of the routes to enhance the electrode performance, particularly for the cathode, is to use new materials with optimized microstructure. In this work, the plasma-spraying technique, recognized to have several advantages over presently used deposition techniques, was used to deposit cathode materials onto ceramic and stainless steel substrates to obtain highly porous structures. Cathode materials with composition of Lao 6Sr0.4Co02Fe0 8O3 (LSCF) were employed in the powder form. The LSCF was prepared from powder precursors with different pore formers and binder levels, or from already produced, single-phase LSCF. The (La0.8Sr0.2)0.98MnO3 (LSM) cathode material was also processed for comparison purposes. The deposition process was developed to obtain coatings with good bond strength, porosity, film thickness and residual stresses. The phase and microstructure of deposited materials were characterized using XRD and SEM.

Jan 1, 2005

By A. Dahi Taleghani, Amir Shojaei

A continuum damage mechanics (CDM) based constitutive model has been developed to describe elastic, plastic and damage behavior of rock during drilling. In addition to inelastic deformations, this model incorporates rock anisotropies like toughness anisotropy due to the bedding planes orientation that is a common observation in soft Shales. The pressure sensitive inelastic deformation of porous rocks together with their damage mechanisms are studied for drained and undrained conditions. Fracture mechanics of microcrack and micro-void nucleation and their coalescence are incorporated into the formulation of the CDM models to accurately capture different rock failure modes. The performance of the developed elastoplastic and CDM models are compared with the available single cutter test data of a specific shale play and then the models are introduced into a commercial finite element package through user-defined subroutines. A workflow to derive the required model parameters is presented through inverse modelling of the single cutter test data. The developed CDM model outperforms the traditional discrete element and fracture mechanics approaches by removing stress singularities at the fracture tips and simulation of progressive fractures like formation of the cuttings ribbon without any essential need for remeshing. This model would provide a robust tool for modeling bit performance and rate of penetration using conventional elements of FEA with a reliable results and a computational cost less than similar computational techniques like discrete element methods.

Jan 1, 2015

By P. W. A Severin

"The Sturgeon Lake deposit, a partly eroded lens of massive sulphides with an underlying sulphide stringer zone, is one of five orebodies that occur in the Sturgeon Lake area of northwestern Ontario within volcaniclastic rocks of the Archean Wabigoon Subprovince in the Superior Province of the Canadian Shield.The Sturgeon Lake Cu-Zn-Pb-A g-Au deposit was discovered in October 1970 as a result of an I.P. survey. Production from this open-pit mine began in March 1974 and continued until the ore was exhausted in March 1980.The Sturgeon Lake property is underlain by basaltic volcanics, minor amounts of mafic lapilli tuff and rhyolite volcaniclastics. A quartz crystal-bearing rhyolite occurs at the top of the felsic volcaniclastics and is ""capped"" by the Sturgeon Lake massive sulphide deposit. The felsic volcanics have been intruded by a crudely layered sill-like, carbonatized mafic intrusion. Recent work suggests that the felsic rocks that underlie the Sturgeon Lake deposit are lateral equivalents of those in the vicinity of the Mattabi Mine and are not correlative with the dacitic volcaniclastics that underlie the Lyon Lake and Creek Zone deposits. Hydrothermal processes that resulted in the formation of the Sturgeon Lake orebody have resulted in a depletion of Na2O, CaO and FeO and an increase in MgO, K2O, copper and zinc. In the vicinity of the sulphide stringer zone, the rhyolites are ""bleached"" due to silicification and sericitization. The rocks lying immediately below the massive sulphides are locally strongly chloritic.The Sturgeon Lake deposit may have formed on a top ographic high which prevented mafic flows and dacitic volcaniclastics that underlie the Lyon Lake and Creek Zone deposits from inundating the Sturgeon Lake fumarolic vent from the west. Continued or resurgent activity from the Sturgeon Lake fumarole may have resulted in the formation of the Lyon Lake and Creek Zones as more ""distal "" deposits in topographic lows. The Sturgeon Lake, Lyon Lake and Creek Zone deposits were subsequently overlain by mafic tuffs and flows."

Jan 1, 1982

By R. W. Zeindler, D. A. Fawcett

"A summary is presented of the report completed by the Coal Mining Research Centre in 1980. This report was of a cross-pit conveyor system applied as an auxiliary mining complement to the major stripping unit, a dragline. The purpose of the CMRC report was to evaluate selective mining and replacement of the upper horizons of the strata as an aid in reclamation. These strata were the topsoil, subsoil and glacial till.Past utilization of cross-pit conveyor systems and related engineering studies were assessed. The parameters of the study were based on the mining and geological conditions of the Alberta prairie coal mines. The principal excavator for stripping was a dragline. Excavation of the upper horizons was done by a bucket-wheel excavator discharging onto the crosspit conveyor. Alternative equipment applications were economically compared. Four cases or geological sections were evaluated in detail. The economics of the alternative mining systems for each of the cases were determined. In all instances, the most economical solution was a tandem system utilizing a dragline with a bucket-wheel excavator/ cross-pit conveyor system."

Jan 1, 1981

By W. Dresler

"A major Canadian chromite deposit at Bird River, Manitoba is one of the largest known chromite reserves in North America but it exhibits low chromium contents and low chromium to iron ratios. Commercial beneficiation techniques permit these ores to be upgraded to concentrations which, however, remain inferior to most other ores and concentrates used worldwide f or production of high-carbon ferrochromium. Analyses for reduction of low-grade concentrates by submerged-arc electrofurnace techniques predict chromium contents between 45.9% and 51% for a high-carbon ferrochromium alloy. Relatively high over-all chromium recoveries between 79.5% and 91. 1% can be achieved. Alloy compositions for Cr, Fe, C and Si are determined for various burdens with low-grade concentrates. Consumption data per ton contained chromium are obtained for electric power, coke, concentrate, quartzite and limestone. The data are compared with those of high-carbon ferrochromium producers in South Africa. Economic aspects are discussed and compared with a South African reference study.IntroductionThe present ferrochromium demand in the western world is estimated at approximately 1.7 Mt with a consumption of approximately 0.36 Mt in the U.S.III and 0.03 Mt in Canada'-', A low estimate of the installed production capacity for ferrochromium in the non -communist world is 2.4 Mt. This production capacity of ferrochromium by far exceeds the demand, which is also evident from the fact that no shortage in supply of ferrochromium to the world markets was encountered in the past. Supply-demand comparisons therefore suggest that in the foreseeable future no new chromite or chromium producers should enter the world markets unless superior chromites or superior technologies are successful in competing with existing producers. Neither one of these conditions exist presently in Ca nada or the U.S., although essentially no ferrochromium is produced and no chromite is mined in these countries at the present time."

Jan 1, 1986

By M. W. Gilmore, J. Ndlovu, T. Sepoloane, Anglo American Platinum, L. R. Nelson, R. N. Varty, L. J. Bryson, B. Peyper, J. P. Hagemann

"As part of Anglo American Platinum’s Rustenburg Base Metals Refinery (RBMR) expansion, a new Nickel Electrowinning Tank House, with a nameplate capacity of 32 400 tons per annum, was constructed. Commissioning of the new electrowinning technology, which involved world first full deposit plating, commenced in 2011.The old nickel electrowinning process at the RBMR used starter sheets which, along with a divided cell configuration, was very labour intensive and exposed operators to high levels of aerosols that contained both nickel and acid. To overcome this problem two key design intents of the new technology are aerosol abatement and minimising labour in the electrowinning cell environment, with a design target to reduce the nickel occupational exposure limit (OEL) to half the legislated limit of 0.1 mg.m-3.Commissioning of the new technologies adopted to achieve mist abatement is described, together with a review of technical and operational challenges relating to the titanium blank edge strips, blank roughness and sandblasting optimisation, blank quality control, electrode spacing, polyconcrete cell dimensional stability and cell top furniture. The impact of these on process performance is presented and the development of fault checking and rectification methods, to maintain high process performance, is explained.INTRODUCTIONThe expansion of Anglo American Platinum’s Rustenburg Base Metals Refinery necessitated the construction of a new Nickel Tank House to achieve two primary objectives, namely increasing the nickel electrowinning capacity from 22 500 tons per annum (tpa) to 32 400 tpa nickel, and a design to reduce the nickel aerosols to 0.05 mg.m-3 as a time weighted average over 8 hours, which is half of the legislated occupational exposure limit (OEL) of 0.1 mg.m-3."

Jan 1, 2016

By H. Sano

Most of the dust generated from the copper smelting process in Chile has been stored after the stabilization by hydrometallurgical process because it contains high concentrations of arsenic. However, in recent years, the dust generation has increased because of degrading the quality of concentrate. In addition, the environmental regulations become stricter. On the other hand, valuable metals such as copper and zinc are contained in the dust at high concentrations and it is desirable to recover them. In this study, the effect of dust recirculation to the smelting process was examined in order not only to decrease the amount of dust but also to recover copper. Dust generation and the distribution of arsenic, lead, zinc etc. among the matte, slag and gas phases were evaluated as a function of the amount of recirculated dust, partial pressure of oxygen and temperature. It was found that the direct dust return to the smelting process was quite effective for the recovery of copper and the reduction of dust generation, but the acceptable dust amount was limited by the produced matte quality.

Jan 1, 2007

By A. J. Basu

Air quality in underground mining operations can fluctuate significantly during the working day, but until recently the only way to ensure a mine had sufficient air quality was to over-ventilate and, with significant delay in adjusting the volume or direction of the airflow, working conditions were tolerable but rarely ideal. Underground ventilation management systems have been considered to achieve improved energy efficiency since at least 1995 in Canada. However, Mine Ventilation Optimization, (MVO) and integrating it with Ventilation on Demand (VOD) is only becoming more of a reality in the last seven (7) years. A systems approach to MVO takes into account all the elements from the point the power is distributed into the ventilation fans through to the actual quality and quantity of fresh air to the working face. Opportunities exist throughout the system for energy savings but not all of them are cost-effective. Depending on the application, these opportunities can be easily realized by properly sizing, streamlining, maintaining and operating the ventilation system using premium mine proven energy efficient components throughout. Implementation of VOD is a key step in achieving the MVO objective. However, VOD is a concept, and it requires various tools, procedures, and strategies for cost-effective and operationally viable implementations. This paper provides a historical background in the development of VOD and provides a framework for proper and cost effective implementation. In addition, an optimized ventilation system will also allow increased airflow by reducing resistances and shock losses. This turn in would allow production target improvement, which could be an attractive objective compared to energy savings. Mine ventilation is the life support system of an underground mine, and contributes to sustainable development and corporate social responsibility goals assuring health and safety aspects of strategic planning. The proposed framework addresses implementing mine ventilation optimization integrating ventilation on demand as a vehicle for energy, health and safety improvement and overall productivity gains in the mining cycle efficiency while significantly reducing carbon footprint of a mine.

Aug 1, 2013

By V. K. Srivastava1

Coal mine fires burn about 20?21 million tons of coal per year throughout the world, which not only results in loss of valuable coal reserves, but also cause serious environmental hazards over large areas. The famous Jharia Coalfield of Dhanbad, India is no exception; here a coal mine fire originally reported nearly a century ago is still continuing unabated in vast areas of the coalfield. In this paper, an attempt has been made to analyse high resolution multispectral thermal images of ASTER for mapping and delineating surface and subsurface coal mine fire areas of this coalfield. From the generated temperature gradient map, as well as from the surface temperature anomaly map, it has been possible to differentiate shallow and deep coal mine fire regions and other erroneous cultural features. It is observed that the coal fires are distributed mostly in the eastern part of the area, which has branched into two major coal fire zones: one along Lodna- Tisra-Bhulanbarari-Kujama-Jealgora Jharia and the other along the Kusunda-Kendudih area. The western fire zone is restricted in Dumra-Nadkhurkee-Jayramdih area. From ASTER thermal infrared data from 2006, the total affected area is estimated to be about 7 km2, of which the deep subsurface coal mine fire area is around 3 km2 and the shallow surface coal mine fire area is around 4 km2, as compared to 18 km2 coal mine fire area estimated in 1987 using Landsat TM thermal band data. In other words, the fireaffected region has decreased by about 50 % during the last 18 years. However, such decrease in coal fire area is seen in the central portion only, and has in fact increased in the south eastern parts of the Jharia coalfield. Study of Differential Interferometery images, generated from Earth Resources Satellite (ERS) synthetic aperture radar (SAR) tandem data has shown that the active coal mine fires are in general associated with low topography/subsidence areas.

Aug 1, 2013

By L. Jiang

This report investigated the dynamic recrystallization (DRX) phenomenon in magnesium alloy AZ31 billets to understand the deformation mechanisms and microstructure evolution during extrusion and other metal forming processes, Compression tests of coarse-grained as-cast magnesium alloy billets containing lamellar Mg17Al12 eutectic phase and (Al, Mn) particles suggest that temperatures higher than 300°C, strains greater than 0,25 and strain rates above 0,l/s lead to the formation of fine DRX grains in the deformed samples. Microstructural observations also indicate particle-stimulated DRX nucleation (PSN) during hot deformation of the AZ31 alloy, facilitated by the presence of Mg17Al12 and (Al, Mn) particles, While the Mg17Al12 is dissolved into the matrix at about 350°C, (Al, Mn) particles may remain effective for PSN at temperatures up to at least 400°C, This study suggests that alloy design with a proper distribution of second-phase particles can provide the desired microstructure for improved properties and formability in wrought magnesium alloys.

Jan 1, 2004

By Hung-wei Liu, Kevin Plucknett

Early attempts to manufacture titanium aluminides using blended elemental powders, through powder metallurgical processes, have been obstructed due to serious swelling during sintering. Although the use of pre-alloyed powder can avoid this undesired expansion problem, there are limited commercial powder sources available. Therefore, in the present research, fundamental studies on the synthesis of dual-phase (? plus a2) Ti48Al intermetallic materials is undertaken, in particular assessing powder manufacture. In order to produce pre-alloyed powders, highly porous Ti48Al pieces are initially sintered from elemental Ti and Al powder blends, and subsequently pulverised into powders. The powder size is then further reduced by use of either dry or wet milling processes (i.e. shatterbox grinding, attrition, or ball milling). Among these methods, shatterbox grinding has shown the highest efficiency, with a slight mechanical alloying effect observed. The manufactured powder morphologies and phases, as well the sintered material, will be discussed.

Jan 1, 2015

By Z. D. Hora

Brick shales and refractory clays are mined at Sumas Mountain near Abbotsford. Sholes and stoneware clays elsewhere in the province have not been developed. THE SUMAS MOUNTAIN deposit near Abbotsford, 80 km east of Vancouver, has been in continuous production since 1905. The deposit is exposed in a small outlier and comprises a sequence of alternating beds of clay and sand. Beds are of Eocene age. Within the 400 m thick ness of sediments are seven distinctive conglomerate members, some up to 20 m thick, interbedded with fine grained sediments including claystones and siltstone , or "shales". Shale is quarried to produce a variety of bricks, sewer pipes and similar products; it is also used for cement. Several different shale beds have been mined over the years and exhibit a variety of fired colours ranging from buff-pink grey to deep red; pyrometric cone equivalents (PCE) range from 3 to 20. A layer of fireclay 3 to 4 m thick that occurs at the base of the sequence has pinkish white to light buff fired colour and PCE of 30 to 33. It is used as a 266 primary component to produce refractory bricks. The shale is quarried and processed by Clayburn Industries Limited of Abbotsford. Another similar but smaller outlier of the same geological formation is known from Blue Mountain, about 20 km northwest of Mission. Other ceramic clays in British Columbia are reported from Quesnel (7 m bed of white stoneware clay, PCE 17 to 19), Giscome Rapids (25 km north of Prince George, 10 m bed of stoneware clay to PCE 31) and anaimo-Comox area (buff to red firing "shales", PCE 8 to 10-1 12) . From 1959 to 1974 Cretaceous shale from Saturna Island in the Strait of Georgia was used to produce lightweight aggregate. Similar deposits of expanding shale are known from the vicinity of Duncan on Vancouver Island.

Jan 1, 1984

By A. C. Headon, K. W. Lam, D. P. Dautovich

"Microbiological activities affecting the performance of materials have been encountered in diverse situations within Ontario Hydro. Case histories of bacterial problems which are presented include ground rod corrosion at transformer stations, corrosion of a bare steel cooling water intake structure in Lake Huron and corrosion of steel components in a nuclear generation station vacuum building. Possible microbiological activities which may affect the corrosion behaviour of containers for the disposal of nuclear fuel waste in the future are discussed, as are bacterial actions suspected of causing an odour problem in residential water heaters.IntroductionBacteria are ubiquitous. Except by use of sterilization methods, bacteria -free environments are no t possible to find. Bacteria lie dormant in hostile environments, spread easily through air and water currents and reproduce rapidly under favourable conditions. Although different types of bacteria have different preferable conditions for growth, they are highly adaptive and in general, whenever there is a source of water and carbon (carbon dioxide or organic matter), there will be bacterial activities . These activities often induce or enhance costly metallic corrosion in industries and water odour problems in rural water supplies . Underground structures and systems in contact with natural water or water containing organic matter are most susceptible to bacterial attack.The types of metal-degrading bacteria , their characteristics and the conditions for growth have been reviewed extensively in the literature(1,2,3). There are several often encountered groups of bacteria which, through their metabolic processes, may lead to the degradation of metals. A large variety of bacteria produce corrosive in organic or organic acids as waste, such as the well known formation of sulphuric ac id by aerobic sulphur oxidizers . Anaerobic sulphate reducers produce hydrogen sulphide which is corrosive and has an obnoxious smell, slime-forming bacteria from slime which shelters sulphate reducers and iron bacteria oxidize ferrous to ferric ion which precipitates as hydrated oxides creating oxygen concentration cells . The following are bacterial problems encountered in Ontario Hydro. Although the number of recognized cases has been few, they show the diversity of location and environment where bacterial problems could arise. These include ground rod corrosion at transformer stations, corrosion of bare steel in a water intake structure, corrosion of steel in a nuclear generation station vacuum building and an odour problem in residential hot water tanks. In addition, possible bacterial- enhanced corrosion in containers for future disposal of nuclear fuel wastes are also discussed."

Jan 1, 1984

By Richard J. Kolada, Ian R. Muirhead

"This paper reports on a CANMET-funded examination of less conventional underground coal mining methods. These methods are documented and those that show the most promise for application to western Canadian conditions are discussed in detail.IntroductionIn recent years, mining considerations and economics have encouraged a transition from underground mining to surface mining. However, a change in market conditions or the development of superior underground mining methods may reverse this trend . Should this happen, the industry must be quick to respond and have information available on the latest developments of underground mining technology. In time, deposits of high-quality coal, which are easily accessible to surface mining, will be depleted and a change to underground mining methods will require consideration. The economic transition point between surface to underground will be a major determinant in maintaining a competitive edge. For these reasons, it is important to keep abreast of improvements in underground mining methods. To meet this objective, CANMET awarded a research contract to Monenco Consultants Limited, to investigate unconventional underground mining methods that show a potential for western Canadaoi. This paper presents the results of this investigation."

Jan 1, 1988

By J. Keith Haddock

"Introduction The Coal Valley Mine is operated by Luscar Stereo (1977) Ltd. with the Alberta Energy Company having a minority interest. The mine produces 2.0 million tonnes of bituminous thermal coal per year. Deliveries include 1.5 million tonnes to Ontario Hydro and 0.5 million tonnes to the export market via bulk handling facilities on the west coast near Vancouver, B.C. There are a number of mining methods utilized at the mine including open-pit by truck and shovel, strip mining with large draglines and stripping with scrapers. The mine is located 100 km south of Edson, Alberta. Geology The coal measures are concentrated within a 210-metre int~rval of the Paleocene section. The coal seams were originally named by the mining companies in the earliest days of development of the area and these names continue to be used today. Of the five main seams, only three are presently economic to mine based on quality, thickness and depth of cover. These are the Val d'Or, Upper Silkstone and Mynheer. The Coal Valley Mine is located in the structurally deformed foothills area of Alberta and the structure of each mining area is therefore very complex. The general bedding strike is 305 degrees azimuth but major thrust faulting and folding has extensively deformed the natural seams as a closer examination will show. The Mynheer Seam, located at the base of the coal measures, ranges in thickness from 5 m to 10 m and has numerous bentonite and shale partings. Because of inherent geological features, the Mynheer Seam has been subdivided into two zones, the Mynheer 'A' and the Mynheer 'B', and the mining of coal in these zones has necessitated the utilization of distinctly different mining methods. The structural regime of the Mynheer 'A' zone consists of an overturned asymmetrical anticline crest containing a steeply dipping major thrust fault which has raised the seam above the present topographic level. Further extensive shearing and rotation of the coal has resulted in the coal taking a 'pod' shape. The Mynheer 'B' Zone is a continuation to the southeast along strike from the Mynheer 'A' Zone. The bedding dips to the southwest at an average of 12 degrees and is interrupted at the south end by a transverse fault and to the north by its outcrop at the surface."

Jan 1, 1985

By J. Font

The RAF or copper fire refining process at the Caletones smelter of CodelcoChile consists of several pyrorefining stages that successively lowers the levels of S, Fe, Pb, As, Sb, Te, Se and to some extent 0 in the copper melt, allowing the production of high quality fire-refined copper of 99.93 % purity (RAF copper). This chemical feature of the RAF copper is only achieved by quite long processing times, and a considerable consumption of fluxes and fuels in the RAF vessels. The main goal of this study was to improve the RAF process performance by thermodynamic considerations and industrial scale tests, i.e., an in situ approach for the process as featured by intensive sampling, characterization and subsequent modifications. Thus, both theoretical and industrial data were derived, and based on kinetic and thermodynamic evaluations, a higher operational standard was achieved for the RAF process. These new operational practices allowed enhancing the overall economic of the RAF process, by reducing the time and operational costs, and consequently increasing the availability of the vessels.

Jan 1, 2007

By P. Rocque, S. Talebi

Although the measurement of blast vibration close to the blasthole is critical to the understanding of rock fragmentation mechanisms and blast damage in the rock masses, limited experience for such monitoring exists. Because much higher vibration amplitude and frequency ranges are expected in rock masses close to an explosive charge as compared to far field vibrations, different problems from those for the far field monitoring must be considered for near field blast vibration monitoring. Currently, guidelines for design of the near field blast monitoring systems do not exist. This paper describes the development of an integrated technique for vibration monitoring close to a blast hole, including selection and installation of transducers, design of a monitoring system and signal recording. A densified cement was designed for grouting accelerometers in order to match p-wave impedance between the rock and grout. The monitoring technique described has proven suitable for blast vibration monitoring within 2 m to 15 m of a blast hole having loading conditions similar to production blasts.

Jan 1, 1993

By F. E. P. PEARSON

Sandstone quarried from an island in Lake Winnipeg is barged 130 km to a processing plant at Selkirk on the Red River. The stone is white, poorly consolidated, and consists of rounded quartz grains of high natural purity. It is an important supplier of silica in Western Canada for glass, fiberglass, foundry and other industrial uses.

Jan 1, 1984

By E. C. Goodhue, R. D. Coleman, I. E. Puddington, A. F. Sirianni

Iron ore samples containing apatite are fractionated to acceptable products by spherical agglomeration methods. The phosphorus is upgraded by a factor of 10 at an elevated pH. High-grade iron products are obtained in good yields from the tailings in a second step of the operation. The grade of the phosphorus separated appears to reach a maximum at about pH = 10; recovery of iron decreases below about pH = 4. Both the recovery and grade of iron are found to be reduced sharply above about pH = 8.

Jan 1, 1968