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By John G. McCamis

The Maritimes Carboniferous Basin is the largest intermontane basin in the Appalachian Mountain System, occupying a total area of 57,200 square miles and containing up to 30,000 feet of late Devonian through Permian .sediments. Deposition began with continental elastics in late Devonian and early Mississippian. Marine deposition is represented by a limestone-evaporite sequence of late Mississippian age. Pennsylvanian and Permian continental rocks deposited largely in flood-plain and swamp environments complete the succession. Marine seismic data disclose several varieties of structure, both halokinetic and tectonic in origin. Recent exploratory drilling in the offshore part of the Basin encountered good reservoir rocks in the Riversdale sandstones, which also provided encouraging shows. The most likely source rocks of hydro~ arbons in the Maritimes Basin are shales in the Horton and Riversdale groups. Potential recoverable reserves of the Maritimes Basin are estimated to be 400 million barrels of oil or 7.8 trillion cubic feet of gas, based on the volume-of-sediment method of calculation.

Jan 1, 1973

By J. N. Van der Merwe, M. Mathey

"We present an analysis of the mechanical properties of coal specimens from various coalfields and seams in South Africa. Our database comprises of 1800 test results from uniaxial and triaxial compression tests, as well as indirect tensile strength tests, which we collected from the various mining houses and research agencies in the country. We inspected the database for possible errors and present a brief description of the verification procedure in the paper.In the analysis, we reveal that the collected samples of strength and elastic properties of South African coals can be represented by single lognormal or normal distributions with only few outliers. This finding indicates that the samples realistically approximate the population of mechanical coal properties in the country and may suggest that the properties are randomly distributed. Significant coalfield- or seamspecific trends for the mechanical properties of coal are not clearly discernible from our data.Typical coefficients of variation for the individual mechanical properties range between 25-50 % on a country-wide and seam-specific level of analysis. Average uniaxial compressive strength values, however, are closely clustered for all seams. A comparison with data available from international coal strength studies show the distinct difference between South African coals and seams in countries of the Northern Hemisphere, where differences in the average coal seam strength are more pronounced.We observe that the number of specimens whose failure mode is influenced by the presence of natural discontinuities reduces drastically with the application of very small confining pressures to the specimens. Further, the strength-reducing influence of discontinuities diminishes with increasing confining pressures."

Jan 1, 2015

By E. V. Manlapig, M. A. Hampton, M. E. Holuszko

Methanol treatment of ZnS particles has been found to remove slimes and facilitate flotation. The removal of slimes renders the ZnS surface more hydrophobic, resulting in an increase in the hydrophobic attractive force between the particle and bubble. Hallimond tube flotation, induction time measurement and particle-bubble force analysis with the atomic force microscope (AFM) was undertaken to link the beneficial effect of methanol treatment of ZnS particles to their increased floatability.

Jan 1, 2009

By J. O. Wheeler

"DEFINITION OF THE REGION, ITS BOUNDARIES, AND PHYSICAL AND GE'OLOGICAL CHARACTERISTICSTHIS PAPER concerns the Western Cordilleran region, embracing most of British Columbia, the southern half of Yukon Territory and the southwestern most part of the District of MacKenzie. It excludes Vancouver Island and the Queen Charlotte Islands, which are discussed in a background paper on the Pacific Continental Shelf. The region is bounded on the south by the northwestern United States, on the west by the continental shelf and Alaska, on the north by the front of the Ogilvie Mountains, on the northeast by the axis of the MacKenzie Mountains and on the east by the Rocky Mountain Trench.The region is dominated by two mountain chains that con tain icefields and glaciers: the St. Elias, Coast and Cascade Mountains in the west; the Selwyn, Pelly, Cassiar, Omineca and Columbia Mountains in the east. The Intermontane region between these mountain chains consists of lower mountains and plateaus. In the mountains, the region above the timberline and many of the steep valley-walls provide good exposures of rock, but these areas are subject to rockslides and landslides and in winter to snow avalanches. Much of the Western Cordillera was covered by ice-sheets at various times during the Pleistocene epoch. Consequently, the larger valleys in the mountains and much of the Intermontane region contain much glacial drift and alluvium and only limited exposures of rock. This same terrain in the Southern Cordillera, however, is the most favourable for agriculture. Parts of the region, particularly in the two mountain chains, are heavily forested. Elsewhere, the forest cover is less, with grassland prevailing in the south and tundra in the north."

Jan 1, 1969

By J. O. Wheeler

"DEFINITION OF THE REGION, ITS BOUNDARIES, AND PHYSICAL AND GE'OLOGICAL CHARACTERISTICSTHIS PAPER concerns the Western Cordilleran region, embracing most of British Columbia, the southern half of Yukon Territory and the southwesternmost part of the District of MacKenzie. It excludes Vancouver Island and the Queen Charlotte Islands, which are discussed in a background paper on the Pacific Continental Shelf. The region is bounded on the south by the northwestern United States, on the west by the continental shelf and Alaska, on the north by the front of the Ogilvie Mountains, on the northeast by the axis of the MacKenzie Mountains and on the east by the Rocky Mountain Trench.The region is dominated by two mountain chains that con tain icefields and glaciers: the St. Elias, Coast and Cascade Mountains in the west; the Selwyn, Pelly, Cassiar, Omineca and Columbia Mountains in the east. The Intermontane region between these mountain chains consists of lower mountains and plateaus. In the mountains, the region above the timberline and many of the steep valley-walls provide good exposures of rock, but these areas are subject to rockslides and landslides and in winter to snow avalanches. Much of the Western Cordillera was covered by ice-sheets at various times during the Pleistocene epoch. Consequently, the larger valleys in the mountains and much of the Intermontane region contain much glacial drift and alluvium and only limited exposures of rock. This same terrain in the Southern Cordillera, however, is the most favourable for agriculture. Parts of the region, particularly in the two mountain chains, are heavily forested. Elsewhere, the forest cover is less, with grassland prevailing in the south and tundra in the north."

Jan 1, 1970

By B. Kenney

For SOFCs, composite cathodes comprising an electronically conducting electro¬catalyst (e.g. LSM) and an conically conducting electrolyte material (e.g. YSZ) are considered to improve the electrochemical performance by extending the active reaction zone to regions beyond the electrolyte-electrode interface, as in the case of conventional cathodes. Interpretation of experimental data for composite cathodes, however, is complicated by the mixed conducting behaviour which results in local overpotential distributions throughout the composite cathode. These local overpotentials depend on many factors, such as the composition, particle size, porosity and thickness of the cathode. Reliable experimental data obtained from composite cathodes requires carefully crafted microstructural parameters in order to minimize the overpotential variations. A mathematical model of a composite cathode was developed using coupled differential equations describing transport and consumption of chemical species, oxygen ion and electrons. Simulations under various oxygen concentrations were used to obtain the reaction order of the oxygen reduction reaction. An apparent po2 dependency was then extracted from the predicted Rp vs P02 data. It was found that this p02 dependency can be significantly influenced by the micro-structural parameters of a composite cathode, primarily due to local overpotential distributions.

Jan 1, 2005

By Bennett McLaughlin

AGNICO-EAGLE started sinking the Penna Shaft in 1995 with a hoisting plant capable of hoisting 1,800 tonnes per day from a 2,240 metre deep shaft. Exploration success lead to the installation of a hoisting plant capable of extracting 4,500 tonnes of ore and 1,800 tonnes of waste per day from a depth of 2,210 metres. The introduction of a new rope selection factor, permitting a safety factor of 4.0, represented the breakthrough required for a cost-effective project. This paper describes the process taken to introduce the new rope selection factor and its impact on the original plant.

May 1, 2001

By P. Mpofu

In this work, the modification of interfacial chemistry of colloidally stable kaolinite clay dispersion has been carried out to improve its flocculation performance and dewatering behaviour. Synergistic action between dispersion pH, hydrolyzable metal ion and high molecular weight polymeric flocculant structure type (anionic polyacrylamide-acrylate copolymer (PAM) and non-ionic polyethylene oxide (PEO)) was found to play a pivotal role in inter-particle bridging, the enhancement of the settling rate and extent of consolidation of the pulps. Flocculation with PEO led to higher settlings rates in acidic than alkaline pH, whilst for PAM, the maximum dewatering rate was achieved in the neutral pH range 6 - 7.5. Upon shear, the PEO flocculated pulps showed dramatic improvement in consolidation to 40 wt%, the extent of which was greater at lower than high pH values. For PAM-based pulps were however, not shear-responsive, lower sediment solid contents of 15 - 23 wt% was observed between pH 3 and 11. Hydrolysable metal ions, Mn(II) and Ca(II), used respectively at pH 7.5 and 10.5 in conjunction with PAM and PEO, significantly enhanced the settling rates and consolidation of the pulps. The findings exemplify the strong links existing between pH-mediated particle surface chemistry. polymer structure-conformation, inter-particle bridging and dewaterability of kaolinite dispersions.

Jan 1, 2004

By M. E. Holuszko

Although there is no widely accepted rigorous definition of handleability, the handling coal characteristics often referred to as handleability define whether a coal has the ability to flow unhindered through the processing and transportation systems. The handleability may be severely affected if fine coal particles tend to aggregate. In the pelletization process, the rolling action of the drum is applied to bring the individual particles into proximity with each other so that they can aggregate and form pellets. Because of apparent similarities between these two processes, the pelletization tests are carried out in parallel to the handleability tests in this project, and the pelletization results are used to explain coal handleability properties.

Jan 1, 2004

By L. J. Han, Y. J. Zong, S. Y. Wen, J. J. Wei

"Stress strain curves characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states were analyzed through triaxial compression tests carried on using TAW-2000 microcomputer control electro-hydraulic servo rock triaxial test system. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression was split failure paralleling to the axis of samples, while macroscopic failure forms under uniaxial compression was shear failure, the shear failure angle of which decreased linearly with confining pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressure, and then based on acoustic emission damage and volumetric dilatation damage the damage evolution properties of samples were analyzed, and damage constitutive model were established, realizing the real-time quantitative evaluation of samples damage state in loading process. INTRODUCTIONDamage is a phenomenon that micro defects in material under monotonic loading or reloading will lead to progressive decrease of the cohesion and damage of volume units. Many scholars at home and abroad have carried out systematic researchers on damage evolution characteristics and constitutive model of rock, and have achieved a series of remarkable results in this field. Lu Y.D. (2004) studied the complete stress-strain curve’s characteristics of marble under triaxial compression, and established the bilinear elastic-linear strain softening-residual ideal plastic damage constitutive model. Ren J.X. (2001) studied the damage evolution laws of coal and rock mass by computerized tomography triaxial loading system, realizing the quantitative evaluation of damage state. Zhang Z.L. (2011) studied the deformation and failure mechanism of strong weathered sandstone by triaxial compression test, and analyzed the damage evolution processes and established the damage evolution equations based on the density method. Li X.J. (2012) studied the microscopic damage characteristics of siltstone under triaxial compression by scanning electron microscope and digital image technology, and analyzed the statistical distribution characteristics of cracks azimuth angle, length, width. Zhou J.W. (2012) studied the strength, deformation and fracture damage characteristics of sandstone by uniaxial cyclic loading and unloading tests, and defined damage variable based on linear damage mechanics theory and acoustic emission (AE). Cao W.G. (2006) established a new damage model and a statistical damage constitutive model of rock under specific confining pressure according to the force of damaged part and undamaged part in rock on the base of statistical damage theory. Li S.C. (2014) studied the damage evolution characteristics in the whole uniaxial compression process of sandstone by electrical resistivity and AE, and proposed a status qualitative criterion for rock damage."

Jan 1, 2015

By Josée Dartois

En 1988, à l?instar de plusieurs états du monde industrialisé, le Québec décidait d?accélérer la cadence de l?assainissement des rejets industriels et lançait un programme intégré de réduction de la pollution industrielle visant, à la fois, les rejets dans le milieu aquatique, les émissions atmosphériques et les matières résiduelles. Ce programme fut intitulé le Programme de réduction des rejets industriels.

Nov 1, 2002

By C. H. Stockwell

THE Eastern Townships of Quebec have been the chief Canadian source of chromite. Production, however, has never been large and, except for a period of steady but small output between 1894 and 1909, mining has been active only in war time. The known deposits are too small or too low grade to compete with overseas sources in normal times. During the last war, shipping difficulties and a greatly increased demand in the United States resulted in high prices and a ready market for low-.grade material. The Quebec chromite industry flourished and played an important part in relieving the wartime shortage. Shipments in 1918 .amounted to 15,600 tons of crude ore and 6,400 tons of concentrates. At the outbreak of the present war it was natural to turn again to the Quebec field as a possible source of this strategic mineral. Some of the old properties have since been opened by private and government money and some new deposits have been found. Total mill capacity is 750 tons per day, as compared with 200 to 300 tons in 1918. During 1940, 1941, and 1942, about 85 chromite deposits were examined by the Geological Survey in a belt 100 miles long and up to 7 miles wide. A part of this belt, about 35 miles long, in which the geological features ?were not well known, was mapped on a scale of 1/2; mile to an inch.? Small ..areas around some of the deposits were mapped in detail, on scales of 20 to 200 feet to an inch. Some geophysical work was done but did not result in the discovery of ore. Prospecting by stripping and trenching was then undertaken and chromite ore was uncovered at several localities. The above work was done by the writer and by J. W. Ambrose, who has kindly contributed his results for incorporation in this paper. Y. O. Fortier actd as assistant in the geological work and, in 1942, was in charge of a sub-party engaged in geological mapping. The author is indebted to H. C. Cooke and J. W. Ambrose for reading the original manuscript and for offering many helpful suggestions for its improvement.

Jan 1, 1944

By H. Miki, S. Wheatley

The addition of precipitated silica greatly enhances chalcopyrite leaching in the presence of sodium chloride at moderate temperatures (65-90°C) in acid media with ferric ions as the oxidant. The beneficial effect increases with the increase in chloride concentration and temperature. The addition of sodium silicate and silica sand has no significant influence. The analysis of solubility data in acid/salt solutions indicates that the solubility of silica as Si(OH)4 as the dissolved species is controlled by the activity of water, as expected from the hydration theory. Kinetic analysis shows the trends that copper dissolution from chalcopyrite in the presence of precipitated silica with sodium chloride follows a shrinking sphere model indicating a chemically controlled surface reaction. The effect of temperature on copper dissolution in the presence of both precipitated silica and sodium chloride was also larger compared to the results in sodium chloride alone. The SEM analysis shows that chloride and silica facilitates the precipitation of sulfur on the surface of the silica particles rather than the chalcopyrite particles which avoids the blockage of the mineral surface and thus improves the leaching kinetics.

Jan 1, 2014

By I. Farr, H. Wittens

"In 1989 and 1990 abnormally high levels of arsenic in ore from the Thompson Open Pit Mine threatened Manitoba Division's electro-nickel production. The paper will discuss our development of a flotation process to separate pentlandite and gersdorffite (the prime nickel and arsenic bearing minerals).The presentation will focus on the development of the process from conception, through lab and plant test work, to plant optimization and full scale production. The paper will conclude with the benefits and cost of the completed project.INTRODUCTIONRejection of arsenic from nickel sulphide ores was not a primary concern in the Manitoba Division until 1989. At that time increased production in the Thompson Open Pit mine, which contains high arsenic ore zones, resulted in excess amounts of arsenic in the Thompson Refinery affecting electro-nickel quality. This problem was resolved through extensive efforts by Mill personnel. The purpose of this paper is to familiarize the reader with- the Thompson Mill.- the mineralogy of the Thompson orebody.- the evolution of Ni/As separation in the Mill.- the metallurgical impacts of the separation on the Mill.- the importance of the separation to the Manitoba Division."

Jan 1, 1991

By P. Abachi

Cemented carbides or hard metals that generally consist of hard tungsten carbide and a tough metal binder such as cobalt are important in many segments of the world economy, ranging from automobile related components to machining, cutting, and drilling tools. For metal cutting operations such as turning and milling, replaceable cemented carbide inserts are frequently used. The exposure of inserts to very severe conditions (e.g. temperatures as high as 1000°C) in combination with very high loads, limits their lifetime. When the tools and components are scrapped, they are collected with a view to recovering the tungsten carbide and cobalt due to both their environmental aspects and their strategic importance. In this work, a selective electrolysis process was used for recovery of WC powder particles from cemented carbide scraps. The WC-10Co and WC-10Co-VC up to 3 wt.% VC was produced using powder metallurgy route. The mean particle size of WC, Co and VC were selected as 2.5, l.5 and 2.2 µm respectively. Referring to electrochemical curves of WC-10Co cemented carbides in hydrochloric acid solutions with different concentrations, the recovery rate was enhanced in IN acid. Therefore, this solution was selected for recycling of all samples. The surfaces of as-produced and corroded specimens were investigated using a scanning electron microscopy (SEM). Detection of corrosion products was provided by energy dispersive spectrometry (EDS). According to results, the selective electrolysis process could be useful in the recycling of scrap carbide materials, although more studies should be undertaken on economical aspects of the process and the quality of samples produced using recovered powders.

Jan 1, 2005

By C. J. R. Braithwaite, Giancarlo Rizzi

"Abstract-The Navan zinc-lead ore deposit (70 million tonnes) is hosted principally (97%) by the Meath Formation (Lower Carboniferous, Courceyan, Navan Group), comprising a lower, mainly carbonate mudstone unit, the Stackallan Member, and an upper grainstone-dominated unit. The Stackallan Member, about 60 m thick, comprises about 35 peritidal cycles including an oolitic grainstone interval. Grainstones forming the upper part of the formation, about 150 m thick, comprise at least six shallowing-upward ramp cycles. Emergence horizons are indicated by subaerial dissolution surfaces, in situ breccias, and a single palaeosol.Most dolomitization at Navan is confined to the Meath Formation. The linear dolomite body, trending NE-SW, has a flattened, laterally limited, tabular geometry in cross-section, suggesting that dolomitizing fluids initially rose vertically, cross-cutting stratigraphic and sedimentological boundaries, although fluid flow was subsequently controlled by these features. Three stages of dolomitization are indicated by textural relationships, cathodoluminescence (CL), oxygen isotopes, and fluid inclusion data. Stage 1 crystals, with generally dully luminescing cores and up to six overlying subsidiary zones, are the main replacive phase. Crystal surfaces are commonly corroded and overlain by bright stage 2 rhombs (which also form new nuclei lining molds and fractures). Three subsets of zones are present in stage 2 crystals: bright, non-luminescent, and dull; these are locally separated by additional corrosion surfaces. Stage 3 comprises relatively large baroque crystals, generally dully luminescent but with up to seven sub-zones. Isotopic and fluid inclusion data suggest growth of successive stages from waters which became progressively hotter (60°-160°C).The distribution of the ores follows the dolomite trend. Ores were precipitated between Stages 1 and 2 of dolomite growth, following Stage 2, and also during the nucleation and growth of Stage 3 crystals. Dolomitization and mineralization appear to have been temporally and genetically related. The cyclic sedimentation of the host rocks, which accentuates lithological and petrographical contrasts between depositional units, controlled dolomitization. The relationship between dolomitization and mineralization, which is closely associated with faults, provides powerful exploration criteria. The recognition of these features in limestones elsewhere in the Irish ore field may point toward unrecognized zinc-lead prospects."

Jan 1, 1997

By C. J. R. Braithwaite, Giancarlo Rizzi

"The Navan zinc-lead ore deposit (70 million tonnes) is hosted principally (97%) by the Meath Formation (Lower Carboniferous, Courceyan, Navan Group), comprising a lower, mainly carbonate mudstone unit, the Stackallan Member, and an upper grainstone-dominated unit. TheStackallan Member, about 60 m thick, comprises about 35 peritidal cycles including an oolitic grain-stone interval. Grainstones forming the upper part of the formation, about 150 m thick, comprise at least six shallowing-upward ramp cycles. Emergence horizons are indicated by subaerial dissolution surfaces, in situ breccias, and a single palaeosol.Most dolomitization at Navan is con?ned to the Meath Formation. The linear dolomite body,trending NE-SW, has a ?attened, laterally limited, tabular geometry in cross-section, suggesting that dolomitizing ?uids initially rose vertically, cross-cutting stratigraphic and sedimentological bound-aries, although ?uid ?ow was subsequently controlled by these features.Three stages of dolomitization are indicated by textural relationships, cathodoluminescence (CL),oxygen isotopes, and ?uid inclusion data. Stage 1 crystals, with generally dully luminescing cores and up to six overlying subsidiary zones, are the main replacive phase. Crystal surfaces are commonly corroded and overlain by bright stage 2 rhombs (which also form new nuclei lining molds and fractures). Three subsets of zones are present in stage 2 crystals: bright, non-luminescent, and dull; these are locally separated by additional corrosion surfaces. Stage 3 comprises relatively large baroque crystals, generally dully luminescent but with up to seven sub-zones. Isotopic and ?uid inclusion data suggest growth of successive stages from waters which became progressively hotter(60°–160°C).The distribution of the ores follows the dolomite trend. Ores were precipitated between Stages1 and 2 of dolomite growth, following Stage 2, and also during the nucleation and growth of Stage3 crystals. Dolomitization and mineralization appear to have been temporally and genetically related. The cyclic sedimentation of the host rocks, which accentuates lithological and petrographical contrasts between depositional units, controlled dolomitization. The relationship between dolomitization and mineralization, which is closely associated with faults, provides powerful exploration criteria. The recognition of these features in limestones elsewhere in the Irish ore ?eld may point toward unrecognized zinc-lead prospects."

Jan 1, 1997

By S. J. Laskowski

In potash ore flotation, carried out in NaCI-KCI saturated brine (about 6-7 molar KC1 and NaCI solution), long-chain primary amines are used as flotation collectors. Long-chain primary amines are poorly soluble in water and their solubility further decreases at high electrolyte concentration. For ionic surfactants there is a characteristic temperature (Krafft Point, KP) below which their solubility is too low for micellization. In a previous study, the effect of pH on the KP of dodecylammonium chloride in water was determined [Q. Dai and J.S. Laskowski, Langmuir, 7, 1361-1365 (1991)]. This paper deals with the effect of electrolyte concentration on the KP of dodecylammonium chloride. The derived theoretical relationship between the KP and the critical micelle concentration (CMC) for dodecylamine can be used to calculate the KP for electrolyte concentrations of up to 0.5 mol/L (about 8% NaCI-KCI brine). A simple experimental procedure for the determination of the KP for higher electrolyte concentrations is also described. The results show that the Krafft point of dodecylamine increases from about 17-18°C (in distilled water) to about 80°C at 16% brine saturation.

Jan 1, 2006

A pilot scale AG milling campaign was conducted at the AngloAmerican Platinum pilot plant in South Africa. Different blends of hard:soft (silicate:chromite) and coarse:fine particles in the AG mill fresh feed were tested. The effects of multi-component feed on the pilot scale autogenous grinding are presented in this paper, and can be used as a guideline for multi-component feed blends for AG milling. Preliminary modelling and simulation for the multi-component AG mill model are also included.

Jan 1, 2012

By C. M. Diaz, S. W. Marcuson

In the late 19th century, the discovery of rich nickel-copper sulfide ore bodies in Sudbury and the need for tonnage quantities of the metal to be used in nickel steel armor provided the foundation for establishing the Canadian nickel industry. For almost 50 years, International Nickel was the key player. In 1930, Falconbridge Nickel entered the field. These two companies remain the key Canadian nickel producers. This paper discusses the factors that have influenced the evolution of nickel smelting processes. The initial Sudbury ore smelting and nickel copper separation technologies were imported from abroad. It was only in 1937 that International Nickel established a process research laboratory in Copper Cliff The explosive post WW II industrial development created a strong demand for a broader variety of nickel products. For both International Nickel and Falconbridge, R&D became an essential business tool to succeed in the new market scenery. In the last few decades, new technologies were developed and commercialized to respond to the raising cost of energy, society pressing environmental concerns, the advent of nickel laterites as an important source of new metal, the incorporation of new nickel producers to the market, and, therefore, the need to increase productivity. Canada thus became an important exporter of technology. In this paper, the authors review this history with the objective of highlighting the forces that have triggered the most important changes in Canadian nickel smelting.

Jan 1, 2005