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By D. F. Zhang, X. Q. Jiang, N. Tahreen, D. L. Chen, F. S. Pan, D. Y. Li

Alloying with rare-earth elements has been proven to be an important tool for magnesium to achieve superior properties via texture randomization. The role of yttrium in texture weakening and the link between texture and formability are fairly well known. Since annealing is a vital part of metal processing which could significantly contribute to ductility, it is important to ascertain the impact of annealing in terms of texture change. Also, an understanding about texture development during pre- and post-deformation annealing is essential to improve the industrial deformation processing as texture is closely related to formability. While there is independent information in the literature regarding the effect of rare-earth addition and heat treatment on the texture formation, no systematic studies have been reported on the collective impact of yttrium addition, annealing and deformation on texture evolution. The present study was, therefore, aimed to identify the inter-relationship among texture evolution, yttrium content, heat treatment and deformation behavior in an extruded Mg-Zn-Mn-Y alloy. Annealing at 450°C for 1 hour and uniaxial compression tests at a certain amount of deformation were performed. The deformed and annealed samples were then subjected to annealing and compression test, respectively, followed by texture measurements. It was observed that yttrium addition effectively weakened the crystallographic texture in all conditions, which was evident from the changes in the microstructures and textures.

Jan 1, 2015

By Eduardo R. Rodrigues, Ankur Narang, Roberto Federico Ausas, U. T. Mello, Jose Maria Segura Serra, M. R. Lakshmikantha, Ignacio Carol, Kamal C. Das

"Modeling of big faults or weak planes of strong and weak discontinuities is of major importance to assess the Geomechanical behaviour of mining/civil tunnel, reservoirs etc. For modelling fractures in Geomechanics, prior art has been limited to Interface Elements which suffer from numerical instability and where faults are required to be aligned with element edges. In this paper, we consider comparative study on finite elements for capturing strong discontinuities by means of elemental (EFEM) and nodal enrichments (XFEM) for Geomechanical applications. For general fracture scenarios, Oliver et al. (2008) have demonstrated advantages of EFEM over XFEM for including: (a) ease of modeling in any standard finite element code due to the possibility of static condensation, (b) higher accuracy in some cases for coarse meshes, and, (c) a reduced computational cost. However, there has been no work that considers cohesive fractures in Geomechanics. We present a numerical analysis based on a linear constitutive model and linear triangular elements for the bulk and a linear constitutive behaviour for the fault for a representative set of fault planes in a circular tunnel made in rock mass. In the numerical examples we consider both well-traced and bad-traced meshes. We focus on traction profile analysis for both EFEM and XFEM, since that is crucial to understand the cohesive fracture behaviour specially rock joint. Therefore in each case, shear, normal and stress ratio are compared across the two methods along the fault plane. This is the first such work that compares XFEM and EFEM behaviour for Geomechanics problems.For the considered class of problems and the sharp penalization approach without regularizations adopted, it can be observed that accuracy and robustness of EFEM may strongly depend on the fault orientation with respect to the element edges, while, XFEM is independent of fault alignment with element edges. It has been also observed that, with mesh refinement model, stress oscillation completely removed with XFEM however EFEM fails to provide oscillation free results with finer mesh in case bad-traced model. We also performed error analysis and found that in case of bad-traced mesh the average error in the XFEM is 84% smaller than of EFEM and for XFEM the error goes to zero with increasing mesh resolution, while for EFEM the error increases with mesh resolution. Thus, we experimentally demonstrate that, XFEM performs better than EFEM in terms of accuracy and rate of convergence with marginal increase in computational cost. This work hence provides novel insights on the application of XFEM and EFEM in Geomechanics."

Jan 1, 2015

By Eric Best

"In the past two to three years, all continuous mining machines at the Potash Corporation of Saskatchewan Mining Limited, Lanigan Division, have been changed over to a new cutting pattern using 1 -inch- and 1-3/l6-inch-diameter self-sharpening pencil bits. The bits are arranged in a cone-type pattern across the face on 2 1/2 -inch and 3-inch spacing. The result is that the ore is removed by chipping and flaking. Previously, rap-lock bits were used, with the pattern being several bits in single rows at wide spacings. The cutting action was grinding and breaking.Besides improved penetration rates and lower bit costs, there are many other advantages. The ore size is much smaller, resulting in less wear and tear on conveyors and other associated equipment. Feeder-breakers are no longer routinely set up at the head end of every extensible belt, as the banana-shaped chunks of ore that used to require breaking are no longer produced. Also, less dust is generated by the cutting heads and fewer stops are required for bit changes. Even the mill operation has been improved, as fewer fines are produced.Further improvements are still sought after, but, all in all, the new cutting pattern is considered to be a giant step forward from the old method."

Jan 1, 1981

Presentation Outline ERM ? corporate profile Background to sustainability reporting GRI G3 Guidelines (Oct 2006) Best practice examples Contact information ERM ? corporate profile Over 35 years of experience World?s largest all-environmental consultancy* 130+ offices in 40+ countries; 3,200+ professional staff Worked with >50% of the Global Fortune 500 (FY07) Annual turnover > US$500 M (FY07) 2008 Environmental Advisor of Year** Offices/Staff ? Canada (5/50) and US (65/1,350) *Source: Engineering News Record: July 2, 2007 ** Source: Acquisitions Monthly: December 2007

May 1, 2008

By E. J. Debicki

"At the 1992 PDAC Convention, Norman Keevil announced the formation of the Exploration Technology Division (ETD) of the Mining Industry Technology Council of Canada (MITEC). It was evident that base metal reserves in Canada were declining and that the cost of discovering a deposit in Canada was increasing. Coordinated research to develop new exploration technologies was required to discover the next generation of ore-bodies. The ETD was formed in response.The mission of the ETD is to contribute to the survival, profit, and growth of the Canadian mining industry by improving the efficiency and effectiveness of mineral exploration through development of innovative technology by man-aging and coordinating applied cooperative research. In addition, it is the intent of the ETD to become the principal agency by which cooperative research funds are transferred to researchers from the mining industry. The division is industry driven, industry funded and industry managed.The ETD’s Three-Year Plan has focussed80% of its research funds toward two objectives, improving the efficiency of exploration for VMS deposits and establishing the parameters necessary to discover the next Hemlo deposit. The remaining 20% is allocated to other projects, with the current emphasis on geophysics.In 1995, corporate members total twenty-three major mining companies accounting for90% of the exploration expenditures in Canada. The ETD is currently managing ten cooperative research projects totalling $4.6million. Other projects, estimated at $1.6 mil-lion, are currently under development."

Jan 1, 1996

By T. Billotte, G. Tirand, J. Zollinger, V. Robin, B. Rouat, D. Daloz

The grain structure prediction of metallic alloys during a welding process is often an issue. In addition to the welding parameters and the alloy nominal composition and properties, the base metal grain structure and chemical homogeneity also play an important role in the formation of the final microstructure. In this paper intensive characterisation of solidification structure in gas tungsten arc welding of Ni base alloy 600 are described. It is shown that in transverse section of the weld, while the grain structure shows some texture following constrained solidification growth, grain density in the weld is similar or greater than grain density in the heat affected zone. This suggests that simulation of the welding structure needs, in order to be predictive, to take into account : epitaxial growth, secondary nucleation events and 3D growth inside the weld pool.

Jan 1, 2015

By Edmund C. Bovey

"AS I begin my remarks this morning, please let me say how honoured and gratified I was to receive your invitation to address you here during your deliberations in historic Quebec City. The high esteem in which your Institute is held is reflected in the respect and deference accorded to it by industry across Canada. I feel privileged to be here with you today.I would like to discuss with you some applications of natural gas in the mining industry and suggest to you, in closing, some possible avenues of future development.Natural gas first became avail-able for industrial purposes in Northern Ontario in late 1958. Acceptance of natural gas, as a source of energy by the industry of that area, has been both widespread and gratifying. The mining industry of Northern Ontario has in-creased its annual use of natural gas by approximately 35 per cent each year since 1958. We believe that this trend will continue, al-though we will probably have to accept a more modest 10 per cent annual gain as the market approaches saturation. I would like to explain how we were able to do this and where all this gas is used. Our first sales were largely a matter of price-and the savings we offered were substantial."

Jan 1, 1966

By P. Babak, E. Insalaco, O. Babak, P. Henriquel

"Detection of outliers is an important primary step in geomodelling. Geological datasets often contain errors due to problems such as measurement device limitations and recording glitches. In this paper, a robust Mahalanobis distance–based approach is successfully applied to particle size distributions of the Joslyn lease, an oil sands development site near Fort McMurray, Alberta, Canada. Automatic outlier detection and geological review were combined. Outliers from the Mahalanobis distance approach were compared with their respective core photographs to determine if laboratory measurements and facies classification were correct. A checking procedure for laboratory technicians is proposed.RÉSUMÉ La détection des valeurs aberrantes constitue une étape primaire importante de la modélisation géologique. Les ensembles de données géologiques contiennent souvent des erreurs en raison de problèmes tels que les limitations des instruments de mesure et des pépins d’enregistrement. Dans le présent article, une méthode robuste basée sur la distance de Mahalanobis a été mise en oeuvre avec succès aux granulométries du bail minier Joslyn, un site de sables bitumineux en développement à proximité de Fort McMurray, Alberta, Canada. La détection automatique des valeurs aberrantes a été combinée à une étude géologique. Les valeurs aberrantes de la méthode de la distance de Manalanobis ont été comparées avec leurs photographies respectives de carottes de forage afin de déterminer si les mesures en laboratoire et la classification des faciès étaient correctes. Une procédure de vérification pour les techniciens de laboratoire est proposée."

Jan 1, 2015

By W. A. MacDonald, C. M. McGibbon, J. H. Reynolds

This paper traces the development of the Seaboard Power Plant, which plays such an important role in the industrial life of Nova Scotia. It also shows the involvement of the plant in the siting of a heavy water production facility in Cape Breton. The paper concludes with an outline of the new installations which the Nova Scotia Power Commission has undertaken as an extension to the Seaboard Plant.

Jan 1, 1966

By G. S. Hume

FOR MANY YEARS Canada lived in the hope of attaining a substantial production of petroleum and natural gas that, to geologists familiar with the sedimentary basins of this country, seemed an entirely reasonable expectation. There have been surges of exploration activity stimulated by oil and gas discoveries and development such as occurred in Turner Valley. However, it was not until the Leduc field in Alberta was found in 1947, and the significance of that discovery was realized, that the search became really intensive and continuons. Expansion now has become a matter-of-fact attitude based on results which would have been considered impossible of achievement a few years ago.

Jan 1, 1957

By A. L. McAllister

"MASSIVE sulphide deposits are found in two areas of New Brunswick, the St. Stephen area and the Bathurst-Newcastle area. In both, the geology in the immediate vicinity of the sulphide bodies is largely inferred from drilling results as outcrop is not plentiful and is, in fact, almost lacking in most places. With few exceptions these deposits have not been explored by underground methods. Consequently much of the. detail on the geology will only become known over a period of years as economic conditions make mining feasible.Much of the information contained in this paper has been supplied directly by company geologists. As a result of the number of contributors, some confusion of nomenclature bas to be anticipated. Cross-sections and plans of the individual deposits are, in most cases, as supplied by the companies concerned. Most of the interpretations are the responsibility of the author."

Jan 1, 1960

By M. T. Ho, D. E. Wiley

The iron and steel industry accounts for almost 5 % of the total world CO2 emissions. Optimisation of the steelmaking process has led to significant reductions in the energy intensity to the point where it is now close to the thermodynamic limit. Further reductions are not likely to be achieved with efficiency improvement alone and will require the development of novel or breakthrough technologies. This paper will show the costs of implementing CO2 capture at direct atmospheric emission points for a number of iron and steel production processes. These include a conventional process, top gas recycling processes, the Corex and Hismelt smelt reduction processes and the Midrex direct reduction process. Depending on the point source emission, costs of capture with existing chemical absorption technology at iron and steel plants can be similar to capturing CO2 at pulverised coal fired power plants.

Jan 1, 2015

By Wm. L. Giachino

"Over the last 10 years, C-1-L has played a significant role in the major advances that have taken place in blasting technology, among them the following: development and introduction of capsensitive slurries; development of bulk slurry systems both for underground and open-pit operations; development of the TOE-DET and ANODET systems of delay blasting;introduction of the NONEL system of initiation;development of the Vertical Crater Retreat (VCR) system of mining.This paper identifies areasin which we foresee further developments in blasting technology over the next 10 years and outlines how and to what extent C-1-L will become involved."

Jan 1, 1980

By Antonius Prayoga

PT Smelting adopted the Mitsubishi Continuous Technology for its copper smelter plant which has been operating since 1998. Through a series of expansion projects, the plant annual production capacity increased gradually from 200,000 to 300,000 tons of copper. There were no significant modifications for the smelter to reach the 50% additional capacity. It was mostly achieved by intensifying the operation of the furnaces by increasing the oxygen content in the furnaces blowing air. Intensive smelting furnace operation caused shorter campaign life of some furnace refractory, especially the melt zone wall on furnace outlet. During each furnace relining, which is done once every two years, severe wall erosion was found. The worst condition occurred in 2007 when the smelting furnace experienced a melt leak through the eroded wall beneath the bath-line coolers. During the 2008 furnace relining, a modification was performed by installing vertical coolers behind the melt zone wall. Additional vertical coolers were installed during the 2012 furnace relining to extend the coverage area. The modification improved melt zone wall integrity significantly by keeping them safely within the two year campaign life. Recently a modeling study was done to estimate the influences of molten waves on furnace wall erosion. The aim of the study was to predict the impact of blowing parameters, such as blowing air velocity, on the melt wave character and wall erosion.

Jan 1, 2015

By M. J. S. Innes

Abstract This paper is an account of an investigation made by the Dominion Observatory with a gravity meter and magnetometer over sulphide concentrations at East Sullivan, Val d'Or, Que., in June, 1947. The topographic relief over the area does not exceed 20 feet. The overburden varies from 0 co 50 feet. The west orebody had been outlined by extensive drilling. The average density contrast between the sulphide body and surrounding rocks is 0.5. Two hundred and sixty gravity and one hundred and ninety magnetic stations were observed. The results are shown on contour sketches. A derailed account is given of the methods employed to reduce the gravity observations. The survey shows that both gravimetric and magnetic methods are useful in delineating sulphide deposits under the conditions in which they occur at East Sullivan. The results indicate that the buried contact of the syenite intrusive southeast of the orebody could be traced with the gravimeter and chat the magnetometer was of little value for that purpose. Gravity anomalies due to the varying depths of overburden are negligible as compared to the magnitude of the total anomalies. Introduction The project was first suggested at a meeting of the Associate Committee on Geophysics of the National Research Council in September, 1946. At that time it was pointed out that the accuracy and speed of operation of the new gravity meters made them of special importance for geophysical prospecting and it was highly desirable to have an objective test of the performance of an instrument of this kind in delineating an orebody of known dimensions and density characteristics. Several years ago, a private company did some work with a gravimeter over the Amulet deposits, near Noranda. Unfortunately, the topography there is rather rugged, with hills and ravines exceeding 100 feet, so that the topographical effects rendered it impracticable to distinguish between anomalies due to the sulphides and those due to surface irregularities. An orebody of a typical nature, where the disturbing topographical corrections were not excessive, was therefore sought.

Jan 1, 1949

By J. Lammers, D. Adams

Most pressure oxidation operations introduce oxygen through a large multi-use nozzle in the vapour space of the autoclave. Sparge pipes extend inside the vessel to the point of discharge below the compartment agitator. However, two zinc pressure leach operations have successfully used a bottom entry oxygen sparge system for a number of years. Recently, the concept has been used in a whole ore gold pressure oxidation operation as well as a copper pressure leach plant. Both of the latter operations also introduce cooling water for temperature control through the same sparge pipe. This paper addresses the benefits of the bottom entry system with regards to autoclave performance and the positive effects on agitator performance.

Jan 1, 2004

By G. M. Behrend

"The mining and processing of mineral ores is a very old industry which is steeped in tradition. Rising demand for metals has recently forced the exploitation of lower-grade orebodies which require extensive beneficiation. The high capital expenditures involved, together with market pressures for high-quality concentrates and pellets, have forced the development of new process technologies which are heavily dependent on automatic process control. Development of suitable instrumentation has been rapid and it is being applied to mining processes today with a high degree of sophistication. The drive for higher efficiency and profitability goes on and has reached a level at which modern digital computers appear to be the only answer. However, the efficient application of a digital process computer is extremely complicated and is therefore approached by the mining industry with considerable hesitation.Some of the benefits promised by the digital computer can be obtained today by other means, which are more manageable and can provide immediate payoff. The result would be a building-block system which would utilize the digital process computer as its final component, to perform true plant optimization, free from routine chores."

Jan 1, 1971

The writer presents a concise summary of eleven recent discoveries made in the Maritime Appalachian area, with suggestions for fur the research. This information may prove helpful to geologists working in other fields and to students contemplating further avenues of research in mining geology and exploration. INTRODUCTION THIS paper is not intended as a research study on the subject, but i. merely a brief review of eleven discoveries that have been made in the Canadian Appalachian area. Furthermore, this is not a critical analysis of the merits of any one geophysical method, but it is an un-prejudiced observation of how these discoveries were actually made and what techniques were apparently most fruitful. Some generalizations are attempted whicl1 may suggest further avenues of research in the field of mining exploration. The writer wishes to thank his colleagues in the field for their comments, which he was able to in-corporate into this paper. In particular, he is grateful to Dr. Paul Bevan and

Jan 1, 1963

By A Falter

Gyroscopic surveying instruments, which apply the physical law of a gyroscope, are being used for deter-mining the azimuth of lines with a high degree of ac-curacy. In the past ten years, gyro-theodolites have been introduced widely for underground orientation in the mining industry of Russia, Germany and South Africa. Gyroscorpic methods eliminate awkward procedures of conventional shaft plumbing, and provide more safety, excellent control and the highest precision at any point under-ground without interference with hoisting operations. The advantages of gyroscopic orientation in geodetic surveys become obvious in primary and secondary triangulation, in the determination of co-ordinates of single triangulation points, using the method of trigonometric re-section and intersection, and when traversing over long distances or in areas with obstructed view. Other fields of application are found in geophysical surveys and in the orientation of technical objects; e.g. radar stations, relay stations and ballistic missiles.

Jan 1, 1964

By Linlin Zhang

Rare earth elements (REEs) are a group of lanthanides elements which have been widely used in the electronic, petrochemistry, metallurgy, and defense industries. Their demand has increased sharply in the past decade with the boom in electronic device production. Some countries now consider them strategic metals for the future and it has been forecasted that REEs may become a dominant contributor to global economy. In the wake of REE exploration, mining and processing, concern has grown over occupational and community health issues and risks. A portion of available literature on this topic however is written in the Chinese language, and thus research information related to health and REE mining is not readily accessible to mineral development planners in countries such as Canada, where REE mining is now evolving. As REEs also represent an important commodity, primarily stemming from Chinese production, it is important to begin to understand the potential health costs related to this mining sector. There are two main objectives of this paper. The first is to present an overview of REE mining with a focus on geological characteristics, global production and uses with particular attention to the main producer: China. The second is to present the results of a literature review (using both Chinese and English sources) on REE mining and health and identifies key occupational and community health issues that require consideration. This paper concludes by identifying some critical issues this sector needs to address to ensure the sustainable development of this mining activity.

Aug 1, 2013