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By K. Buxmann

Climate change is a subject of growing concern. Based on the International Energy Agency, about 19% of man made greenhouse gas emissions globally are generated by the transport sector. This paper will focus on the environmental aspects of the light-weighting in transport and the resulting savings of fuel and electricity. Aluminium is an option for lightweight applications in transport, with very high benefits not only in the use stage, but also in the stage of vehicle recycling. Life cycle assessment is used to quantify the relative benefits of light-weighting specific components of cars, commercial road vehicles, buses, ships and trains. A vehicle consists of many components, which are produced by different processes and undergo different types of end-of-life operations. This document does not intend to compare a generic aluminium vehicle with a generic "heavy materials" vehicle. It rather tries to use a pragmatic approach based on specific examples of components where aluminium is used and can be used in the design of new vehicles, also taking into account future developments. The case studies in this paper are based on real cases where aluminium was used. For each component, sensitivity analyses are applied to see the impact of specific parameters such as the end-of-life recycling rate and the use stage driving distance. Significant greenhouse gas savings by the use of aluminium are demonstrated for cars and even higher ones for trucks, buses, trains and ships. In addition, the total potential benefits of light-weighting with aluminium are shown on the global level.

Jan 1, 2007

By L. E. Reed, I. G. L. Sinclair

An exploration program seeking kimberlite pipes, the common primary hosts for diamonds, Was' conducted during the years 1979 through 1982 in the James Bay Lowlands of Ontario by Selco Mining Corporation (now the Mining Division of BP Resources Canada) and Esso Minerals Canada. The area to be explored was selected on the basis of its regional geological setting, and because of the known presence of kimberlite indicator minerals in the region. The primary exploration technique was low level airborne magnetic surveying, followed by detailed ground geophysics. This work located many pipe-like bodies, with diameters of a few hundred metres, as well as several dykes. Targets located by these geophysical methods were drilled, intersecting a total of45 intrusions, consisting of34 alkaline diatremes containing tuffisitic breccias, 7 carbonatites, and 4 massive alnoites. K-Ar determinations indicated ages of 152 Ma and 180 Ma for two of the massive alnoites. The texture and general mineralogy of the tuffisitic breccias are similar to those of diatreme facies kimberlites, but detailed examination of their mineralogy and chemistry demonstrated that they lie within the alnoitic rather than the kimberlitic compositional field. Although the exploration program did not lead to the discovery of true kimberlites, it did demonstrate the presence of a large, previously unknown province of alkaline volcanic activity, which has no surface expression.

Jan 1, 1991

By L. K. Nenonen

"Given the properties, locations and quantities of material to be hauled and the dump locations and capacities, the designer wishes to select the type and number of trucks and loading equipment required. Accordingly, software is being developed to assist in creation of the equipment, material and road network data bases, in selection of equipment, materials and road networks from these data bases, and in evaluation of the expected productivities both in a rapid, non-interactive, approximate fashion and a more detailed interactive fashion which permits the user to act as superintendent, if he so chooses. The basic technology has been developed and applied to an open-pit copper mine and is being refined and generalized for oil sands and coal mining applications.BackgroundA set of mathematical and interactive computer models are under development to aid in the selection of equipment and operating policies for an open-pit oil sands mine being planned by Canstar Oil Sands Ltd. This paper describes the computer models being developed of truck haulage systems. Although the interactive truck haulage model is based primarily on a model developed by the National Research Council in collaboration with Glenayre Electronics Ltd. of North Vancouver and Lornex Mines Limited(2).(3l, substantial changes and improvements are being incorporated to greatly increase its generality re equipment types, road network characteristics, dispatching and supervisory policies, etc. Although this paper is principally devoted to the truck haulage model, discussion is included concerning its interactions with other models."

Jan 1, 1982

By D. E. Macdonald

"Approximately 2.0 million tonnes of phosphate rock is imported from the U.S. to Alberta annually and is used in the production of agricultural fertilizers. No phosphate rock is presently mined in Canada, although sources of igneous phosphate have been mined in the past. Sedimentary phosphate rock is found in nine geological units within the Cordilleran Foothills and Front Ranges region of Alberta. The Devonian-Mississippian Exshaw Formation, Permo-Pennsylvanian Rocky Mountain Supergroup, and the Jurassic Fernie Formation have the best potential f or future development. Most of the phosphate rock in Alberta is of low grade and lies within restricted land use areas. The best over-all resource potential lies in the Fernie basin area of southeastern British Columbia, in the Fernie Formation. The possibility of deep phosphate rock deposits in the plains region should be examined.Phosphate rock is mined in Idaho, Utah, Montana and Florida, and is shipped to Canadian fertilizer plants for processing. Raw phosphate rock is acidified, usually with sulphuric acid, by a wet process. Varying amounts of ammonia are added, and the fertilizer is pelletized. Future research, in western Canada, is needed in the beneficiating of low-grade ores and in the area of in situ mining. At the present time, phosphate rock sells for around US$50Itonne, and Alberta fertilizer companies probably pay in the range of C$7D-$85Itonne for U.S. phosphate rock delivered to the plant. Environmental concerns about phosphate rock processing are centred around gypsum tailing ponds, and radioactive wastes.U.S. supplies of phosphate rock are secure until the year 2000; however, by this time, the richer deposits in the U.S. may be exhausted. Alternate deposits, such as the ones in Alberta and British Columbia, might then be considered. Phosphate byproducts, such as uranium, vanadium, fluorine and rare earth elements, may help in making the processing of low-grade Canadian phosphates economically feasible."

Jan 1, 1988

By A. P. Williams

"This paper presents an overview of plant electrical systems in general, a discussion of the problems that may occur due to plant growth, the maintenance required to maintain the reliability and safety of the electrical system, and the selectivity of the relay protection system. It is divided into two main areas: short circuit levels within the plant electrical system; and relay protection systems.This information is directed at maintenance supervisors, mine managers and electrical superintendents who have been away from detailed short circuit and relay coordination calculations for some time. It points out the potential problem areas within an operating plant electrical system. Short Circuit LevelsTheoryThe electrical equipment in a plant such as breakers, switches and starters has two short circuit ratings, the momentary rating and the interrupting rating. These ratings may be given in MVA or current (amperes) depending on the equipment and manufacturer's preference. Since for a three-phase system MVA and amperes are related by the formula"

Jan 1, 1987

By Dave M. Jakelski, Gerhard W. Heinrich, Peter F. Wells, Daniel F. Suarez, Jamie B. Beauchamp

"A need for increased copper concentrate production and for less nickel contamination in that concentrate at Falconbridge's Strathcona Concentrator during 1993 required the installation of a third flotation column and improvements in the operation of the existing circuit. Innovations in wash water distributor and launder design were fundamental in achieving objectives on a new 3 meter diameter column. Minnovex plug-type spargers were tested on a 2.1 meter diameter column in order to reduce maintenance requirements. The paper details the measures taken to enhance column flotation circuit performance and the results obtained.IntroductionFalconbridge's Strathcona Mill receives 10% of the ore feed from a rich copper zone in the Strathcona mine. This ore typically grades 7% copper and 1 % nickel and, because of its high copper content, it is processed in a separate circuit ('C' circuit) which consists of conventional grinding, rougher flotation with the concentrate being treated with lime to pH 12.3 and cyanide followed by column flotation. The columns are operated with mechanical flotation scavengers and the scavenger concentrate is returned to the column feed. Testwork conducted in 1991 showed that the original flotation column (Column 2) could only produce 5.5 mtph of concentrate with less than 0.5% nickel (Figure 1).Between 1991 and spring of 1993, production was increased at times by open circuiting the scavengers. Metallurgical improvements were obtained by improving the wash water distributor of Column 2 and by wash water sprays in conventional cells (1 ). However, the scavenger concentrate assayed 0. 7 -0.8% nickel and was not acceptable for long term operation. When Copper ore production targets were significantly increased for 1993, it became clear that an additional flotation column was required. The new flowsheet employs mechanical scavenger cells on the column tails as in Column 2 circuit (Figure 2). A -parallel configuration was chosen as pulp solids fraction has been shown to be a critical variable and the second column in series would receive a lower density feed."

Jan 1, 1994

By M. Silver, R. H. McCorkell

The effects of covering materials on radon emanations from uranium mine mill tailings were investigated. Granular materials with air in the spaces allow radon to pass freely. Moist covers of compost or soil decrease radon emanation from tailings. Water-saturated covers were more effective, and freezing the tailings with these covers further decreased radon escape. Water itself is a poor radon barrier probably due to circulation. Plants had no effect on radon emanation through soil. Although radon diffusion through water-saturated powders appears to be very slow and inefficient, about 25% of the radon escaping from the grains in water-saturated tailings diffuse to the surface and emanate when no cover is present. The radon escaping from tailings through covers of water-saturated compost or soil is no more than could be accounted for by radon produced in the covers themselves.

Jan 1, 1987

By A. L. Craven, J. P. L. Bacharach, D. B. Stewart

"Inert gas use for underground mine fir e control is a well-established mature technology in some parts of the world. This paper reviews three candidate inert gases and describes three case histories where inert gas fire-fighting technology was used in actual underground fires.IntroductionInerting is the introduction of an inert gas into an atmosphere in contact with a fire to reduce the level of oxygen and hence the intensity of the fire 10 the point of extinction. The benefits of inerting include:a. Reduced Explosion HazardBy displacing oxygen from the atmosphere surrounding the fire the risk of secondary gas explosions is reduced. For example, simple methane-air mixtures at standard temperature and pressure are non-explosive below 12% oxygen. In actual mine fires, combustible gases may include hydrogen and carbon monoxide as well as methane. Such gases are also rendered non-explosive with oxygen removal to below 40/0. Fuel-rich oxygen-deficient mixtures can however be made explosive through dilution with air. Such dilution can occur downwind of the fire. It is also important to remember that the atmosphere in a sealed-off fire zone is rarely homogenous.b. Reduced Fire Intensity and SpreadIn a fire zone the initial combustion may well set alight materials surrounding the fire. Inerting can reduce the intensity and spread of secondary combustion and can cool the area surrounding the fire zone after the fire itself has been extinguished.c. Reduced Air LeakageLeakage of air into sealed areas in excess of the natural leakage may be reduced either by introducing inert gas into the leakage paths to replace air or by pressure balancing seals and providing a chamber of nitrogen on the outbye side of the seals. Both methods assist in the reduction of the intensity of combustion and hasten oxygen starvation."

Jan 1, 1986

By Gordon A. Gross

During the last half century major steel industries of the world have become dependent on iron and manganese resources derived from siliceous ironformation sediments. More than two billion years ago vast amounts of iron and manganese were deposited in ironformation sediments on all continents and until recent years their genesis was considered to be a uniquely Precambrian phenomenon. Research work has demonstrated that the origin of the banded ironformations was related to major tectonic features and associated volcanogenic processes that were active throughout geological history. Similar sedimentary-tectonic environments are being explored on the seafloor where metalliferous sediments are forming today. Ironformations are now considered to be a major part of the stratafer group of stratiform metalliferous deposits. They developed in sedimentary basins in areas where deep tectonic fracturing intersected high thermal gradients in the earth?s crust and gave rise to profuse volcanism and the hydrothermal effusive discharge of metals in the vicinity of the volcanic centres. Concepts for the genesis and metamorphism of stratafer deposits as revised in the last half century have had a profound impact in the development of iron ore resources and have had a dramatic impact in the use of metallogenetic concepts for guiding exploration for other mineral resources. They are based on the tectonic history and stratigraphy in the sedimentary basins, the role of hydrothermal volcanogenic processes , as well as environmental and sedimentation factors which influence the deposition of silica, iron , and other metals that were emphasized in the past. Topics of special interest in the genesis of ironformation and stratafer deposits and for guiding mineral exploration are: biomediation in their sedimentation and genesis, the significance of metamorphism in the processing and beneficiation of iron ore and in the genesis of iron ore by natural enrichment processes, syngenetic concentrations of Mn, Ti, Cu. Zn, Pb, Ni, Co, REE, F, Ba, B, As, Hg, W and Au in ironformations and stratafer lithofacies, and the mobilization of gold and other elements by alkaline solutions during diagenesis of ironformation and other stratafer metalliferous sediments.

May 1, 2003

By V. Shumila, T. Butler

Microseismic monitoring systems listen to a rockmass and record ground vibrations associated with brittle rock fracture. Modern systems record continuously and can identify as many as one thousand small and possibly larger magnitude events occurring each day from induced stress change and redistribution. This paper presents examples of the real time use of microseismic information in mining applications. It shows how alerts can quickly identify large magnitude events or unexpected clusters of seismicity and how seismic re-entry protocol can help to improve safety decisions. Additionally, newly developed advanced analysis techniques applied to mine seismic data sets are shown including the use of clustering methods to see into a cloud of seismic data to identify significant activity and quantify possible planar features. The use of source parameter trend analysis is shown to be a beneficial method for interpreting changes in relative stress levels. Seismic moment magnitude distributions are analyzed using the TGR (Truncated Gutenberg Richter) and TMD (Tapered Moment Distribution) methods to estimate bvalue and expected maximum magnitude. Seismic hazard analysis is shown as a useful way to simplify a dataset and highlight seismic hot spots. The rockmass response to excavation is a complicated spatial and temporal process and microseismic monitoring is a method that can be used to help understand the location and mechanics of failure occurring in the rock ultimately helping to improve safety and productivity at a mine site.

Jan 1, 2015

By D. Tao

The adverse effects of clay particles on coal and mineral processing processes such as gravity separation, flotation, filtration, and thickening are well known in the mining industry. In particular, the presence of ultra-fine clay particles deteriorates froth flotation performance, which has been attributed largely to slime coatings that inhibit bubble attachment and to adsorption of the frother and/or collector by the clay particles. The present study was conducted to evaluate the performance of clay binding agents developed by Georgia-Pacific Resins, Inc. in enhancing coal and mineral flotation performance. Mechanical and column flotation tests were carried out using coal and potash samples. Process parameters investigated include slurry solids percentage, impeller rotation speed, binder dosage, collector dosage, etc. Flotation results show that use of GP reagents significantly enhanced flotation efficiency under different conditions. The required binder dosage and conditioning time was about 1 lb/t and 0.5-1 min, respectively. More significant improvements in process performance were observed at higher solids percentage and higher impeller rotation speed.

Jan 1, 2006

By B. H. Sadagah

"Construction of mountain roads at north westerly Saudi Arabia is a difficult task in rugged terrains, where the rock masses are steep slopes, and full of geomorphological constraints.Werka descent lies at the north west region of Saudi Arabia. The Werka descent, constructed four years ago harmed due to rainstorm. The rock masses are metabasalt and metaryolite tuff rocks. The road is eight m-wide, surround by unsupported sharp manmade slope cuts, reaches up to 15 to 40 m height on both sides. Failures took place at both sides of the road, and blocked it. The road of almost 2 km long subjected to all modes of slope instability such as rockfalls, manmade slope failures and debris flows in the absence of the remedial measures. The very precipitous 40 m-high rock slope-cut along the road has no benches, backed by a natural slope of almost 80 m height. Both types of slopes suffer from rockfalls and slope failure’s incidents, frequently took place mainly in rainy seasons. The steep manmade rock slope cut is less than 1 m close to the road, with no ditches, form a potentially source area for rockfall’s hazards.Intensive geotechnical study includes utilization of the RMR and GSI rock masses classifications indicates that the rocks are fair to poor quality. The DIPS, RocFall, Swedge, RocTopple, RocPlane computer program, in addition to GIS and DEM image utilized to perform modeling and deterministic analysis, in order to suggest the mitigation measures for the natural and manmade slope cuts and rockfalls. The seismic coefficients of 0.1 to 0.4 taken into consideration in modeling processes. Input parameters to model the rockfalls and slope failure’s characteristics were studied such as GSI, block size; seeder points, locations of fallen blocks; slope angle, restitution coefficients, and slope roughness. The programs modeled the proposed location, height and energy of the rockfall barriers, collectors, and rock bolts. Two manmade slope cuts studied and modeled utilizing the integrated techniques were to eliminate the risk of slope failures and rockfalls through the construction of remedial measures, this is the study objectives."

Jan 1, 2015

By The Hollinger Mill Staff

ALTHOUGH cylindrical grinding mills have long been used, there is wide divergence of opinion as to what constitute best operating conditions. Questions such as mill diameter, diameter-length ratio, revolutions per minute, type and size of grinding media, volume of charge, circulating load, pulp level, pulp consistency, liner design, and size of feed, have all been given serious consideration by competent scientific investigators as well as by operators. While many laboratory and plant tests have been made that would seem to justify certain definite conclusions, there is a dearth of definite data giving actual results obtained when a grinding mill working between fixed limits is operated at its maximum capacity under varying conditions as to ball load, circulating load, speed, etc. In tests conducted recently at the Hollinger, extending over a period of thirteen months, to determine the best operating conditions for a ball-mill 6 ft. 6 in. diameter inside the liners, some very interesting facts have been ascertained. This paper is presented in the desire to make public the results of these tests and not with the idea that the last word has been spoken in regard to grinding. We feel, however, that these facts justify certain definite conclusions and hope that, by the fullest and frankest criticism and discussion, the essentials necessary for the correct design and operation of grinding mills will become better known.

Jan 1, 1937

By G. A. Fenton, A. Vervoort, M. Alvarez Grima

"High-risk underwater mining operations necessitate characterizing spatial heterogeneity and resource uncertainty. Local average subdivision is a method of simulating spatial deposit variability inside a cell through a sequence of discretization stages, during which a cell is further subdivided into four or eight cells. New developments are presented to validate simulated deposit models and deal with point measurements of geotechnical and ore-grade properties. This paper illustrates the relevance of translating spatial deposit variability into financial or operational performance indicators during underwater resource exploitation. Two synthetic case studies highlight the challenges of underwater mining in relation to production plans and equipment selection.RÉSUMÉ Les opérations d’extraction minière subaquatique à risque élevé exigent une caractérisation de l’hétérogénéité spatiale et de l’incertitude de la ressource. La moyenne locale de subdivision est une méthode de simuler la variabilité spatiale du gisement dans une cellule par une séquence d’étapes de discrétisation durant lesquelles une cellule est subdivisée en quatre ou huit cellules. De nouveaux développements sont présentés afin de valider les modèles de simulation des gisements et de traiter des mesures ponctuelles des propriétés géotechniques et de teneur du minerai. Le présent article illustre la pertinence de traduire la variabilité spatiale du gisement en indicateurs de rendement financier ou opérationnel durant l’exploitation subaquatique de la ressource. Deux cas synthétiques soulignent les défis de l’exploitation minière subaquatique par rapport aux plans de production et de choix des équipements."

Jan 1, 2015

By W. G. Q. Johnston, J. S. Fox

"A semi-continuous belt of Aphebian magnesian extrusive and related sub volcanic rocks has been delineated by the authors over a distance of 150 kilometres in the central La Ronge lithostructural domain in Saskatchewan. They range in composition from peridotite to basalt and attain true thicknesses of up to 800 metres. For the most part, they are confined to a basal position in the La Ronge/Wasekwan metavolcanic sequence, and appear to have been extruded onto sialic crust. However, at Lynn Lake, Manitoba, in the eastern continuation of the domain, similar rocks seem to be found only at a relatively high stratigraphic level.Although metamorphism seems to have obliterated any quench textures that may have existed in these rocks, ultramafic pyroclastics, pillows and amygdules as well as intercalated, fine-grained clastic sediment attest to the volcanic nature of these rocks. Bulk chemical analyses indicate that these rocks are heterogeneous, with komatiites, tholeiitic picrites and even rocks with some of the characteristics of boninite all being present. The close temporal and spatial relationship of ""boninites"" and komatiites in the belt may suggest a high degree of Aphebian mantle inhomogeneity in the domain.Nickel-copper mineralization has been found in differentiated tholeiitic stocks within the La Range domain (e.g., at Lynn Lake), but none has yet been found in the ultramafic volcanics. However, the tholeiitic picrites do host one economic gold deposit - the Agassiz Mine at Lynn Lake .Because of the depleted nature of their mantle source, the ""boninites"" of the domain are not considered to be likely hosts for mantle-derived nickel sulphide mineralization. However, the opposite is true of the komatiites, and this points to the need for whole-rock geochemistry in setting priorities for nickel exploration in the belt. In contrast, all of the magnesian rocks of the domain probably have the same gold potential. Inasmuch as the geophysical response to gold mineralization in the domain is likely to be unpredictable, lake-sediment geochemistry, followed by base-of-till and/or alteration oriented lithogeochemistry, should be emphasized during gold exploration."

Jan 1, 1981

By B. Jena, M. Rigaud, S. C. Panigrahy

"The influence of flux addition on the structure and properties of pellets produced from low silica specularite with peat moss and bentonite as binders was investigated. Specific pellets basicities in the range of 0.4 to 3.2 were obtained by the addition of limestone or a combination of dolomite and limestone as flux. A t basicities < 1.6, the bonding in the pellets was provided by a glassy silicate phase. At basicities =1.6, calcium ferrites were the predominant bonding phase. When dolomite was added as a flux, presence of magnesia-ferrite was noted. The reduction behaviour of pellets at different basicities was found to be influenced by the type of flux and binder. The pellet compression strength and swelling characteristics were improved with increased basicity.IntroductionThe properties of iron ore pellets are influenced by the type and nature of the ore or concentrate, additives and their subsequent treatment to produce pellets. The interaction between various constituents of the concentrate and additives, i.e. iron oxides, gangue and fluxes etc. result in the formation of various mineralogical phases which affect the degree and nature of bonding achieved in the pellet and the structure and distribution of pores. The pellet properties such as pellet strength and reducibility are influenced by the extent and type of bonding achieved between the ore particles. In view of the present emphasis on the production of high quality pellets to meet progressively stringent quality control requirements, it is essential to investigate the effect of additives on the bonding mechanism and properties of the pellets.In the past, the effects of additives on the bonding mechanism of pellets have been investigated. It is important to note that the conditions and parameters to be controlled are typical of a given concentrate/ore. In this paper, the results of the investigation on characterization of fluxed pellets produced from a low silica specularite concentrate are reported.This investigation was also aimed at assessing the suitability of peat moss for use as a binder for the production of low silica fluxed pellets. Peat moss is abundantly available in the vicinity of iron ore mines in Quebec and encouraging results have been obtained du ring the production of high silica acid and fluxed pellets."

Jan 1, 1992

By L. Tong, D. Robinson

"The stirred milling of nickel laterites offers possibilities for improving liberation and selective size reduction of soft nickel-bearing minerals in laterites. Batch grinding tests were performed in a netzsch™ lME4 stirred mill on siliceous goethitic, goethitic, and saprolitic nickel laterites. Tests on the -2,000 µm sample displayed the effects of selective comminution. The -38 µm product of grinding the -2,000/+38 µm feed confirmed the effects of selective grinding and nickel upgrading. Size classification followed by stirred milling is recommended for nickel upgrading. The energy requirement in the stirred milling was also investigated.RÉSUMÉ le broyage par billes de latérites comportant du nickel offre des possibilités d’amélioration de la libération et de la réduction sélective de la taille des minéraux nickélifères tendres dans les latérites. Des essais de broyage en vrac ont été effectués dans un broyeur à billes netzschMD lME4 sur des latérites nickélifères à goethite siliceuse, à goethite et saprolitiques. Des essais sur l’échantillon -2000 µm présentaient des effets d’une comminution sélective. le produit -38 µm de l’alimentation -2000/+38 µm confirme les effets d’un broyage sélectif et du rehaussement de la teneur en nickel. Pour améliorer la teneur en nickel, il est recommandé de classifier le minerai en fonction de sa granulométrie, puis d’effectuer un broyage à billes. l’énergie requise pour le broyage à billes a aussi été étudié."

Jan 1, 2015

By Bruce W. Downing, Philip G. Claridge

"The availability of environmental data is a major concern in the development of an exploration project through the permitting and feasibility stages. The collection of these data should ideally start very early in a major exploration program. Although a large proportion of the environmental data can also be used for exploration purposes, (e.g. stream-sediment, soil, and rock analyses), environmental sampling will rarely have been initiated at an early date. For the Windy Craggy project, a major environmental concern is the potential for generation of acid rock drainage from waste-rock piles. The project is reviewed with respect to the environment of the deposit, deposit geology, mineralization and reserves, the sequence of exploration activities to the present, the potential for the development of acid rock drainage, the geochemistry and water quality, and the integration of exploration and environmental databases and their application to environmental planning. IntroductionIn the classical sense of exploration of a mineral deposit, the efforts throughout exploration are routinely directed at confirming the existence of the deposit and defining its extent, grade and continuity. Environmental issues are usually tackled separately, possibly by different personnel at a later date. When that is the case, an opportunity is lost to build, from an early date , a comprehensive database that (I) will satisfy the needs of conventional exploration and environmental monitoring, and (2) is usable as a predictive tool for environmental impact assessment.The concept of environmental geochemistry is not complex. The availability of environmental data is a major concern in the development of an exploration project to the feasibility and permitting stages. The collection of data should ideally start very early in any major exploration program. In many cases a significant proportion of the geochemical exploration data gathered early in the life of a project will also be used later for environmental purposes (e.g. stream-sediment, water, soil, and rock analyses). Rarely, however, will the data gathered in a geochemical exploration program provide information as complete as that attainable if environmental objectives had been considered in scoping the work.A knowledge both of local and regional geochemical processes can lead to a better understanding of environmental impacts. This understanding is the basis upon which good environmental management practices may be built. Geddes Resources Limited has undertaken a major study of the natural environment in the Windy Craggy area which includes geology, surface and underground waters, soils, stream sediments, glaciers and geomorphology (Geddes Resources Limited, 1990). This paper deals with the building and integration of the exploration and environmental databases."

Jan 1, 1993

Pillars are used in various forms in underground mining. For several decades pillar design has been an issue in both soft and hard rock underground mining. The major use of pillars is in room-and-pillar type mining. Pillars are critical structures in the production levels of block cave mines. With most mines leaning towards the use of block caving for ore extraction today, pillar design has become even more important. Empirical pillar design is popular. The use of numerical modeling is becoming more common in the design of underground mine pillars. A critical review of both the empirical and numerical modeling approaches to the design of underground mine pillars reveal some fundamental flaws. In general, pillar design approaches often assume the pillars are vertical, and are subjected to pure compression. Pillar failure criteria are then based on this assumption. Most papers on numerical modeling for pillar stability assessment use vertical pillars. This paper shows that where pillars are not subjected to pure compression the empirical pillar design approaches are inadequate, and that when using numerical models for the assessment of pillar performance, more care is needed in the determination of the average pillar stresses. The practice of relating field scale pillar strength to laboratory scale intact rock strength determined from conventional laboratory compression tests in empirical design equations is misleading when pillars are inclined or subjected to compressive and shear stresses. New data is added to the hard rock empirical pillar stability chart, and it is shown that it is misleading to conclude that failure of pillars with width to height ratios greater than 2.3 should not be anticipated. New empirical pillar design charts are presented for pillars at various degrees of inclination for different ko-ratios.

Aug 1, 2013

By D. Ortiz, J. R. Frias, E. D. Mast, J. J. Fañas

Falconbridge Dominicana (Falcondo) has operated an integrated tpy nickel laterite mine and ferro-nickel processing plant since 1972 in the Dominican Republic. The operation includes mining, a processing plant, an oil refinery, and a power plant. Falcondo has improved process efficiency over the years via modernisation and better understanding of the process. The present business environment of high fuel prices and high nickel prices present a challenge and an opportunity to Falcondo&apos;s operation. This paper gives an update of Falcondo&apos;s process, improvements in energy consumption, factors affecting energy consumption and how Falcondo is facing up to the current business environment.

Jan 1, 2005