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By Jean-François Dorion

In an underground mine rock reinforcement elements and surface support units are often exposed to conditions that make them susceptible to corrosion. These unfavourable conditions include high relative humidity, the presence of dust and various other particles in the atmosphere, splashing of water and gases from blasting and diesel equipment. The corrosion of support systems is often associated with a loss in capacity that can be a major safety and economic concern in underground mines. A support system is composed of several components such as bolts, mesh, plate, retaining nut, cable ties. Every individual component can deteriorate due to atmospheric or aqueous corrosion and consequently can damage the integrity of the support system. This paper reports the results of a 5-yr study on the loss in capacity of individual support and reinforcement components at selected underground hard rock mines. As part of this investigation corrosion coupons were installed at selected locations at participating mines. A number of these coupons were recovered at regular time intervals and analysed for any signs of corrosion and subsequently tested to quantify any loss in capacity. The testing of the corrosion coupons was complemented by similar tests on recovered mesh and friction bolt specimens from the site. The collected data have provided useful insights on the factors that contribute to the corrosion of support systems. This knowledge can aid in the selection of appropriate support strategies and a reliable assessment of the predicted useful life of a support system and the need for rehabilitation.

Jun 1, 2012

By J. H. Morrish

"The delivered price of any mineral is the determining factor in converting untapped resources into economic resources. Transporting the minerals from the mine to the market plays a significant part in the total package. The expansion of the Western minerals industry in the last ten years has been paralleled by improved transportation systems to reduce cost, increase accessibility of resources and get the minerals to market in the shortest time possible. A review is made of developments, such as unit trains, complex multi-modal systems and containerized transport, over the last ten years, with specific movement outlined. The total transportation package of land transport, port and terminal facilities, and water transport, where needed, is stressed. As the volume of minerals movement expands, increasingly sophisticated and integrated transportation systems will have to be utilized. The development of solids pipelines and other possibilities is outlined."

Jan 1, 1973

By R. E. Phelan

Introduction The Flin Flon deposit was discovered by Tom Creighton, an experienced prospector and trapper, who in 1914 made his headquarters at The Pas, Manitoba, and still lives there. The discovery was made in the fall of 1914, and Creighton and his associates spent the next summer in investigating the find. In August of 1915 the first claims were located. The property was optioned to Hayden Stone & Company, and in the spring of 1916 they started a diamond-drill campaign. Hayden Stone spent $50,000 on the property and, among other things, completed over 7,500 feet of diamond drilling. The ore not being as high grade as expected, and also being complex in character, Hayden Stone then abandoned their option. In the spring of 1917, Messrs. Earle, Faskin and associates took an option on the property and started an extensive drilling campaign. This campaign accomplished approximately 18,000 feet of drilling and secured for the Faskin interests a 32 per cent interest in the property. In 1920, W. B. Thompson and The Mining Corporation of Canada secured an option, and, while this option was in force, sunk two shafts in the ore-zone and did a considerable amount of drifting and cross-cutting in the ore to study the manner in which it occurred in place, and, by actual channel sampling, to check the grade indicated by the previously accomplished diamond drilling. All of this work had indicated that an ore-body existed on the property containing at least 18,000,000 tons of ore, assaying as follows: gold, 0.074 oz./ton; silver, 1.06 oz./ton; copper, 1.71 per cent; and zinc, ). 45 per cent (1). Complete analyses of composites from the drill holes showed that the ore was very complex in character. It contained the above values in gold, silver, copper, and zinc, as well as large amounts of sulphur and iron, and traces of lead, arsenic, antimony, cobalt, and various other metals. Although the ore was obviously pyritic in character, pyritic smelting, the usual method of treating this class of ore, could not be used to beneficiate the ore with any reasonable expectation of making such a venture a financial success, since coke and coal landed at Flin Flon would be expensive, and siliceous flux was known to be scarce locally and low in grade. The property therefore lay idle until 1925.

Jan 1, 1935

By A. Proulx

Durant les années 1955 à 1961, plusieurs campagnes d?exploration ont été menées sur la zone Bond dans la partie sud-ouest de l?anneau nord de la carbonatite d?Oka (propriété de Niocan, figure 1). Les zones minéralisées HWM1 et HWM2 sont découvertes à l?ouest de la propriété. Un des forages, le S-60, avait intercepté 80 mètres de minéralisation à 0.71% Nb2O5 à l?est des zones HWM1 et HWM2 mais aucun autres travaux d?exploration n?avaient été réalisés sur cette interception minéralisée. En 1995, Niocan réalise une campagne de forage pour mieux définir la zone minéralisée recoupée par le forage S-60. En 1997, une seconde campagne de forage détermine un tonnage de 14.37 Mt avec une teneur de 0.66 % Nb2O5 pour la zone S-60 (Marcotte et Gagnon, 1997). Le complexe carbonatitique d'Oka se situe à environ 35 km à l?ouest de Montréal sur la rive nord du lac des Deux-Montagnes. Sa formation remonte au Crétacé précoce (entre 117 à 123 Ma). La carbonatite d?Oka fait partie de la suite d'intrusions alcalines que constituent les collines Montérégiennes. Le complexe a une forme allongée (7.2 km par 2.4 km) orientée NO-SE (figure 1). Il est intrusif dans des roches précambriennes constituées d?anorthosites au nord et de gneiss charnokitique au sud (Gold, 1963) appartenant à la Formation de la colline d?Oka. Les gneiss au contact du complexe sont fénitisés sur une épaisseur qui peut atteindre jusqu?à 60 mètres. Les roches carbonatitiques forment la série dominante du complexe et elles sont composées principalement de calcite (> 50 %) à gros grain et parfois rubanées. Les minéraux accessoires les plus communs sont la biotite, le pyroxène, la monticellite, la magnétite, l?apatite, la forstérite, la mélilite, le pyrochlore, la pérovskite, la niocalite, la pyrite et la pyrrhotite (Gold, 1963).

May 1, 2003

By W. Dziurzynski, St. Wasilewski, T. Palka, A. Krach

"Air parameter monitoring systems, regardless of gasometrical protections, provide a significant number of measurement data. The obtained data broadens the knowledge on processes taking place in underground workings and shows the relationships and influence of machines and technological processes on the variability of ventilation parameters in the areas of longwalls. Nowadays, computer simulation methods are increasingly used to reproduce the flow of air and methane mixture in the area of longwalls equipped with shearers. The paper presents the results of a research experiment covering a long-term observation of a longwall area during mining with a shearer using sensors from the mine's monitoring system. Data from sensors for methane concentration, pressure and velocity were used and additional ventilation measurements were taken to determine the parameters characterising the air flow in the area. The influence of different machine cycles in the longwall on the changes of air parameters in the area of the longwall was shown. A numerical model of the ventilation area was developed and the computer program VentZroby was used for the calculations, which allows for the simulation of the process of ventilating the area of the active longwall during the extraction of coal with the use of a shearer and haulage of the run-of-mine. Computer simulation of the influence of the shearer's operation and the methane inflow associated with the distribution of the mixture of air and methane was carried out. The results of the simulation were compared with the data recorded by the monitoring system’s sensors during the measurement experiment. Comparison of the recorded methane concentration courses with the results of a computer simulation of the air and methane flow conditions in the mining area showed changes in the gassiness. INTRODUCTION Studies carried out in the Polish and global mining industry show that methane is an obvious factor in limiting mining production due to the loss of continuity in the operation of longwall complexes in hard coal mines under methane emission hazard (Schatzel et al., 2008). In addition, methane hazards have a significant impact on the safety of the operators of machinery in the longwall. The requirements of Polish regulations and the practice of safe operation of mining longwalls require correct determination of gas concentration, volume flow, as well as pressure and temperature of the flowing air. As part of the research undertaken in the Budryk (Wasilewski, 2010) and Bielszowice (Dziurzynski et al., 2009) mines to assess the methane hazard in the longwalls and workings in the vicinity of the longwall, research experiments were carried out, during which air parameters were recorded by the mine monitoring system and additional testing equipment in different cycles of shearer operation."

Jan 1, 2019

By David E. Pearson

"There are many tests that can be used to characterize and classify coals, and describe their quality. One of the easier tests, and most versatile in its application, is petrography. Rank and coal type are precisely defined by petrographic evaluation, and in this paper they are compared with other definitions of rank and coal type. Brief descriptions are given of the various rank tests, and of rheological and coking tests used to describe coking-coal quality in Canada. Similarly, tests used to evaluate thermal coal quality are discussed. Finally, the use of these tests as parameters to classify Canadian coals is examined with reference to four coal classifications.Introduction Among all coals there are two independent variables that are required to evaluate coal quality. These are, coal rank and coal type (or composition), and although coal petrography can be used to precisely define them, other methods are often used to provide values that are, in fact, functions of rank and coal type. For example, volatile matter yield is used as a proxy for rank, and free swelling index is used as a proxy for coal type in the International Classification of Hard Coals by type. Currently, there are a number of methods in use in Canada to define rank. The approach taken here, (obviously the author's bias), is that Romax, the mean maximum reflectance of vitrinite, is both a quick and an accurate measure of rank. It is logical to compare the other techniques employed in the measurement of rank to this favoured method. Coal type is, in theory at least, simply a quantitative measure of the various varieties of coal. In practice, the microscopic entities are assigned to a Reactive or Inert category, and at that point objectivity fades from petrography. Despite this somewhat subjective approach, petrographic composition of coals remains an independent variable of such.importance that its place in the evaluation of coal is essential. In this paper, a variety of me.thods that are used to assess rank and coal type are reviewed and compared; the influence of these variables over other parameters that are used to determine the quality of metallurgical and thermal coals is examined, and their usefulness in coal classifications is discussed."

Jan 1, 1985

By Randy McMeekin, Chris Twigge-Molecey, J. Peter Blake

The business objectives of a metallurgical project determine targets and constraints, such as the range of products, production capacities, in-service dates, and capital and operating cost parameters. Permitting is usually left to the project team, as are decisions regarding site location, technology, and construction approach. Success requires an orderly methodology, represented in this book by front end loading (FEL) phases: FEL1 examines several alternative approaches; FEL2 ranks and eliminates less economically or technically attractive options; and FEL3 develops the preferred option to the point of major permit completion, with defined scope, schedule, and cost to submit for approval to proceed with implementation in FEL4. Working through FEL1, FEL2, and FEL3, the project definition improves, estimates become more accurate, and project risks are reduced. The project design basis at the end of FEL3 is the control document for project implementation in FEL4.

Jan 1, 2015

By Erwin L. Zodrow

"IntroductionThrough an extensive coal sampling project in the Sydney coalfield of Nova Scotia during 1981 - 1984 involving a majority of the mineable coals (Zodrow, 1985, Fig. 1), a sizeable inventory on trace, minor and major metals was established. In this paper, results of studying the inventory are summarized, concentrating mainly on the relationship that exists between metal variations and thickness of coal channel samples (i.e. trends) and on explaining the trends in geochemical and sedimentological terms. As an over-all conclusion the Everglades peat of Florida is proposed as a modern-day analogue to Upper Carboniferous peat swamp development that took place in the Sydney Basin.Data InventoryFor this study 17 channel samples were cut , 8 cm to 14 cm channel width and 8 cm to 10 cm depth, from 10 successive coals which in stratigraphically descending order are as follows: Point Aconi (3), overrider Lloyd Cove (2), Lloyd Cove (2), Stubbart (2), Harbour (4), Backpit (I), Phalen (,I), Shoemaker (1) and McAulay (I), where bracketed values signify the number of channel samples cut from a seam (Zodrow, 1985, Fig. I). Each channel sample was subdivided by 15 em incremental length yielding a total sample size of 137 for analysis. By appropriate modern techniques these samples were analyzed to determine concentration levels for 32 chemical elements and ash content, the average results of which are presented in Table 1.Tests were also made for Pd, Pt, Ga, Nb, Cd, Cs, Sm and W but their concentration levels in many instances hovered on the lower detection limits that were used and on this accounts are excluded from discussion. Ashing, when necessary for the determination of concentration levels, was done for 12 hours at a temperature not exceeding 450°C. Concentration levels for the elements are reported in reference to whole-coal or whole-coal equivalents and discussed on this basis. In the course of the analyses, lower detection limits received careful attention."

Jan 1, 1986

By G. W. Sparkes

The use of CR-39 plastic polymer as a solid state nuclear track detector in the textural analysis of radioactive minerals in geological samples was first described by I.R Basham in 1981. CR-39 autoradiographs provide a detailed, high-resolution image of the in situ distribution of the radioactive minerals within geological samples on both the macroscopic and microscopic scales. This technique is an inexpensive and effective means of obtaining detailed textural information that provides insight into the style of mineralization, its relationship to primary and secondary structures in the host rock, and its association with particular geological features or mineral phases. Although this technique does not provide any information on the identity of the minerals responsible for the radioactivity, the resultant autoradiographs can be used to select regions for further detailed analysis such as petrography, microprobe analysis, or SEM imaging. This paper summarizes the procedure and outlines the appropriate time and materials required for both the exposure and etching of the CR-39 with respect to the intensity of the radioactivity emitted by the geological samples.

Jan 1, 2013

By D. W. Hayley

The rapid expansion of exploration drilling with anticipated production facilities for oil and gas in the Mackenzie Delta region of the Northwest Territories has created a demand for granular construction materials. This paper discusses the technique adopted and experience gained by the authors from several major resource evaluation programs in this remote area. The first part of the paper describes a methodology for deposit identification, logistics of helicopter and ground-based drilling operations and the sampling difficulties which are unique to permafrost: soils. The second part describes the exploitation of a large glaciofluvial deposit at YaYa Lake on Richards Island. Granular construction material is sparse in the delta region relative to projected demand. Exploitable sources of granular materials for aggregates or construction borrow are found in glaciofluvial deposits of Pleistocene age or in outcrops of Paleozoic bedrock. Glaciofluvial landforms can be located by reference to published surficial geology maps coupled with airphoto interpretation. Preliminary assessment of these features in a large region is most economically carried out during the summer months with a drill that is transportable by helicopter. Once prospective borrow pit sites are identified, a detailed ground-based winter drilling program must be undertaken to establish aggregate quality and quantity, and to provide information on natural features which could affect development. The glaciofluvial terrain has been highly modified by the formation of massive ground ice within the gravel deposits. This presents some unique pit development problems which are not encountered in a normal bedrock quarry operation.

Jan 1, 1977

By D. J. McCulla

Mineral development and utilization affect the health of the economy and the pattern of long-term development throughout Canada. There are many diverse opinions on the contribution of minerals to the economy, but there is a dearth of adequate quantitative information. This paper discusses some recent research and provides some new information.

Jan 1, 1977

By P. Cleyle, J. H. Masliyah, R. S. Chow, Z. H. Xu, Z. A. Zhou

Bubble nucleation in water under dynamic conditions was investigated using an autoclave at an air saturation pressure of 7 atm. Agitation during air saturation of water was found to be crucial in enhancing tiny bubble formation. More bubbles nucleated on hydrophobic surfaces at a higher agitation rate, due to cavity formation by the more intense hydrodynamic conditions. Flotation recovery of bitumen from oil sands demonstrated a significant role of bubbles nucleated in water: more than 50-170% increase in bitumen recovery from different oil sands was obtained by using air supersaturated than the regular water.

Jan 1, 2009

By H. Qi, J. L. Feng, D. J. Li

"In the present paper, the characteristics of the granite burst under loading/unloading conditions was studied by means of both laboratory experiment and finite-discrete element method (FDEM). After gaining the mechanical properties of the granite samples under uniaxial compression conditions, the parameters taken as input arguments in the FDEM modelling were then carefully calibrated so as to provide some basic data including Young’s modulus, Poisson’s ratio, uniaxial strength, Lame constants, cohesive strength, and frictional angle for further being used in simulating granite bursts. All the simulating results by the FDEM were basically in agreement with that obtained from the uniaxial compression test and triaxial granite bursts in laboratory, respectively. This study shows that that such computational mechanics of discontinua can be employed to gain powerful insight into the failure mechanism of granite burst, which could also be a useful tool to clarify the collapse mechanism of rock structures in rock engineering design and rock test scheme optimisation. INTRODUCTIONBased on discontinuum state a priori, discontinuous modeling techniques that are commonly referred to as discrete element methods (DEM) treat the material directly as an assembly of separate blocks or particles, which was originally proposed by Cundall (1971) and Cundall and Strack (1979) from the viewpoint of analogous molecular dynamics simulation to better account for and understand the interaction between the blocks. The distinct feature of these formulations is that a constantly changing problem of geometry and contact conditions can be addressed by solving the equations of motion using an explicit time marching scheme (most often in a ‘leap-frog’ format), while updating contact force histories as a consequence of contacts between different discrete elements and/or resulting from contacts with model boundaries (Bicanic 1998). The most notable implementations of DEMs are arguably represented by the universal distinct element code (UDEC) (Itasca Consulting Group Inc., 2013) and the particle flow code (PFC) (Itasca Consulting Group Inc., 2012). Another formulation is the discrete crack framework that is based upon some criteria for an advancement of crack front, which is coupled with extensive local and global re-meshing while simulating by numerical methods such as finite element technique, commonly using fracture theories. Certainly, it is relatively easy to trace the propagation of single crack front governed by some principles of energy release rates (Ingraffea 1997) but tracing of multiple cracks leads to topological and algorithmic complexities. Otherwise, there is no consideration of interacting cracks in these formulations of finite element or enhanced finite element techniques (e.g., in XFEM and ABAQUS)."

Jan 1, 2015

By Claude Hubert, Alex C. Brown, Pascal Marquis, D. M. Rigg

"Numerous studies of the Bousquet mining district, Abitibi, Quebec, mainly following the successive discoveries of new gold deposits over the past two decades, have led to a broad range of genetic hypotheses for their gold deposition. A compilation of petrographic, structural, and geochemical data indicates that the gold deposits are composed chiefly of pyritic schists derived from felsic and mafic volcanic and volcaniclastic protoliths, and of auriferous massive pyrite hosted by pyritic schists of felsic affinity. The deposits are typically located within zones of local pyrite enrichment and advanced-argillic alteration which are in turn enclosed within much larger zones of disseminated pyrite included in regional-scale, commonly anastomosing, zones of sericitic alteration.Overprinting relationships between three sets of folds and foliations indicate that the host-rocks of the gold deposits have retained the imprint of three successive generations of ductile deformation resulting from regional dynamothermal metamorphism. Sericitic and advanced-argillic alteration, together with massive sulphide deposition, are interpreted to have taken place prior to the onset of the ductile deformation, based on observations 1) of altered fragments of wallrocks which are enclosed within massive sulphide bodies and were thus preserved through regional metamorphism, 2) of the syntectonic deformed pyrite, and3) of the syn-tectonic porphyroblasts of andalusite, garnet and plagioclase. The orebodies are oblate to prolate, and the pyrite-gold mineralization is typically vein-type, distributed in foliation-oblique and foliation-parallel veins. The gold-bearing structures postdate all foliations, and are associated with retrograde alteration assemblages that are pseudomorphic after pea~-metamorphic porphyroblasts in host-rocks, and with cataclasticfabrics that overprint syn-metamorphic pressure-solution features and annealing fabrics in pyrite.Retrograde gold-bearing assemblages indicate a chemical disequilibrium between the ore-forming fluids and their host rocks. This disequilibrium rules out the possibility that gold was remobilized from its own host, and suggests, instead, that the ore-forming fluids and their metal contents had an allochtonous source. Stable and radiogenic isotope analyses indicate that the fluids had a metamorphic origin, and that the associated alteration took place after the culmination of the Kenoran orogeny."

Jan 1, 1990

By R. Holmestad, M. Gazizov, S. Wenner, R. Kaibyshev, J. K. Sunde

"Mechanical properties and microstructure of an Al-4.7Cu-0.74Mg-0.51Si-0.48Mn-0.10Cr-0.09Ti-0.02Fe (wt. %) alloy subjected to various thermomechanical processing (TMP) have been investigated and compared to conventional ageing at 170°C (designated T6). Three TMP routes involving cold deformation of solution treated samples were tested. These were (i) 3%-stretching (T8-3%), (ii) equal-channel angular pressing (ECAP) to true strain (e) of ~1 (T8-1) and (iii) ECAP to e~2 (T8-2), all with subsequent ageing at 170°C for 0-96 h. At peak age conditions, both yield stress, ultimate tensile strength and elongation-to-fracture decreased for the T8-3% state as compared to the T6 condition. Intermediate ECAP (T8-1 and T8-2) lead to significant increase in maximum yield stress, ultimate tensile strength and elongation-to-fracture. The changes in mechanical properties were related to microstructure evolution, encompassing changes in grain sizes, dislocation densities, precipitate morphology and phase fractions, which were characterised using transmission electron microscopy. Relations between TMP, precipitation behavior and contributions to different strengthening mechanisms are evaluated.INTRODUCTION Al-Cu-Mg-Si alloys are widely used as structural materials in aerospace industry due to their attractive combination of high specific strength, good fracture toughness and enhanced creep resistance. These properties are largely due to the formation of a large number of nano-sized metastable precipitates during artificial ageing (Polmear, 2006; Eskin, 2003; Gazizov, Dubina, Zhemchuzhnikova, & Kaibyshev, 2015). The precipitation behaviour in these alloys is complicated and depends among other things on Cu concentration and the Mg:Si ratio (Wolverton, 2001; Chakrabarti, & Laughlin, 2004). In general, the precipitation sequence has been presented in a prior study (Eskin, 2003) as follows:"

Jan 1, 2018

By J. G. Pearson, F. H. MacDougall, A. G. Galley

The difference in age, host rock lithology, alteration and style of mineralization indicates a fundamental difference in the format ion of gold deposits in the Flin Flon and Amisk Lake areas. The Flin Flon area contains early quartz-sulfide-gold veins fo rmed within intermittently active fractures and later plutonic hosted deposits thought to be generated in a porphyry system. In the Amisk Lake area two types of gold occurrences are recognized: I) gold-quartzcarbonate- sulfide veins within or flanking fault zones and 2) structurally and stratigraphical ly controlled zones of dissem inated and vein type sulfide-gold mineralization within extrusive and intrusive rhyolite and dacite porphyries. Both types of deposits are set within supracrustal rocks. are accompanied by intense alteration haloes and were formed prior to the major deformation event suggesting an early, epigenetic hydrothermal origin.

Jan 1, 1986

By N Robb

This paper gives an account of the laboratory testing, plant testing and final inclusion of the two-stage sulphuric acid leaching process in the Milliken mill. Operational results for September, 1962, are presented, showing a uranium extraction of 95.5 per cent, with a saving of some 16 lbs. of 100 per cent H~S04 and some 9 lbs. of lime per ton milled. Methods for effecting further improvements in the process are indicated. HISTORY P RIOR to the incorporation of two-stage leaching, the process for the treatment of uranium ores at Milliken consisted of a single-stage sulphuric acid leach, followed by a solution recovery step involving washing in thickeners and two-stage filtration. The thickener overflow solution was subsequently concentrated and purified by ion exchange, and the uranium was recovered, by two-stage precipitation, as ammonium diuranate. Figure I illustrates this flowsheet. For satisfactory extraction of uranium from the. Milliken ore, a high residual acidity, of the order of 40 grams per litre of free acid in the discharge solution, must be

Jan 1, 1963

By Jae-sang Ahn

As the amount of construction information used in the growing construction field increases, the importance of efficient construction field management has been growing. Therefore, construction industry have been tried to introduce and conjugate various software and IT technology such as PMIS, Web Camera, RFID, GPS, PDA. However, existing IT technology especially PMIS have not been performed systematically because of difficulty of real time information collection and decision-making from the insufficient handy equipment. These problems make construction manager cannot efficiently respond to diverse condition occur in construction sites. In addition, after the completion, individual who use PMIS have to move another site and use another system so than cannot use information from previous sites. On the other hand, development of IT technology transmute PDA phone for text-based work like schedule management, internet research to smart phone for network based multimedia service. In other words, smart phone is not just IT equipment but new way for overall industry and it can satisfy the demand IT technology on construction sites. Therefore, the purpose of this study is introduce mobile based individual unit PMIS system using cloud computing and SNS which is in development progress. It is expected to be possible to collect and record the real-time information that occur at the site and make rapid decisions based on the recorded information, by converting the office works that are managed based on the site PC or Web, if the site management system that is based on the smart phones and Cloud computing that will be constructed through this research are utilized. After this study, it is necessary to research about interwork with project unit PMIS system and test on real construction site.

Aug 1, 2013

By Pierre Sauvé, Guy Perrault, Armand Savoie, Pierre Trudel

"La Mine Doyon est une entreprise détenue à parts égales par Cambior Inc. et par Minerais Lac Ltée qui en est l'opérateur. Les statistiques de production au 1"" janvier 1990 indiquent que, depuis le début de son exploitation (1980), 10.3 Mt de minerai d'une teneur moyenne de 5,9 g Au/t ont été usinées. Les réserves sont estimées a 10,4 Mt à une teneur moyenne de 6,6 g Au/t jusqu' à une profondeur de-450m.Trois zones minéralisées sont présentement en exploitation. Ces zones sont caractérisées par la présence de veines de quartz-pyrite accompagnées localement de chalcopyrite. Les roches encaissantes sont les schistes a séricite (zone# 1), les roches volcaniclastiques de composition felsique (zone #2) et intermédiaire (zone #2, zone ouest) ainsi que les roches intrusives appartenant au pluton de Mooshla (zone ouest). Toutes ces roches ont subi un métamorphisme régional dont l'intensité correspond à la limite supérieure du facies schiste vert ( -425°C}.Les zones minéralisées sont situées à I' intérieur des zones de déformation et d'altération les plus intenses. L'étude des structures mineures nous indique que la région a subi plusieurs épisodes de déformation ductile a fragile qui sont antérieurs, contemporains et postérieurs al a minéralisation. L'analyse structurale indique également que la déformation majeure est associée à une importante phase de compression orientée N-S a NNE-SSW.L’ensemble des observations suggère que la minéralisation et I' altération associée sont de type épigénétique. La mise en place du minerai se serait effectuée à la fin de l'épisode principal de métamorphisme et de la déformation."

Jan 1, 1990

By Emmanuel Henry

Hanging wall deformation monitoring at the Kiruna Mine is a major concern for Luossavaara- Kiirunavaara AB (LKAB) since underground production is deepening towards the Kiruna Town. In the quest for more effective monitoring techniques, LKAB decided to evaluate satellite-borne Synthetic Aperture Radar (SAR) interferometry?s ability to monitor ground subsidence by generating continuous deformation maps from satellite radar images. While adopted by other geoscience-related industries, SAR interferometry is still relatively untested in the Mining industry. This paper describes how subsidence is actually monitored on the Kiruna Mine?s hanging wall and gives an insight on SAR interferometry?s principle. The encouraging results are discussed as well as the technique?s benefits (continuous deformation mapping, low cost, fast, etc) and limitations (sensitivity to snow and vegetation cover).

May 1, 2003