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By T. Yalcin

"This paper describes a process that can provide high rates of dewatering and that has the potential of bringing significant savings in tailing disposal costs. It involves a three-stage, closed-circuit operation employing a hydrocyclone, a settling cone and a thickener. The mill tailing, with adjusted pulp density, is first fed to the hydrocyclone. The underflow from the hydrocyclone goes to the settling cone for further dewatering. The overflows from the hydrocyclone and the settling cone are sent to a thickener which, with the addition of a flocculant, gives a clear liquid effluent and a dilute underflow which is recycled back to the hydrocyclone. The underflow of the settling cone is a material with as high as 78% pulp density and is suitable for direct disposal or for use as mine backfill.INTRODUCTIONDewatering is an essential process for the disposal of mill tailings and forms an additional cost item in milling operations. Cost-cutting measures are therefore desirable in this area as in any other stage of milling. One way of achieving this is through increased rate of dewatering which would require smaller dewatering units with correspondingly lower capital and operating costs."

Jan 1, 1987

By D. L. Millar

The hydraulic air compressor (HAC) is driven only by water, held up by a dam, to create relatively low head (typically 10-20 metres), such that the developed hydropower is used to cause flow in openings deeper underground. Air is entrained in the water at the inlet to the sub-surface openings (an air to water volume ratio of 1:1 is reported to be optimal) and is compressed as it is carried along by the deepening water flow. At depth, and with lower water velocities arising from larger cross sectional area tunnels, air bubbles separate out of the water flow and are collected in a receiver space above the flowing water. Water, free of air, then passes back up a return shaft (up-pipe) and rejoins the river or stream flow. In principle, an HAC can produce any pressure and flow rate required, given large enough shafts and enough water supply with head sufficient to overcome frictional resistance in the sub-surface tunnels. Practically, as air solubility in water increases with pressure, HAC installations with depths greater than 100 metres may lead to higher rates of compressed air loss, without special separation measures. A modern HAC application for mine refrigeration and cooling is presented.

Aug 1, 2013

By P. Maltby

"Smelter Feed Preparation Falconbridge Nickel Mines Limited, Sudbury Operations, operate 4 mills and a smelter to produce Bessemer Ni-Cu matte for refining in Norway. Approximately 1400 tons of Ni-Cu concentrate are produced daily which are dried from a filter cake containing 14% moisture to 7.5% moisture pellets. Concentrate drying is done by 4 rotary dryers as shown in the 'Dryer Performance Data' at four separate locations. The dryers all form part of the feed preparation stage prior to sintering.The rate at which concentrate can be produced through the Sinter Plant largely depends on the quality of the dried product which makes up the feed. A feed consisting of mostly hardened pellets will sinter much faster than a feed which consists of broken pellets and dust. Dryer products require:1. Good green strength to survive shipment and handling.2. Correct moisture content.3. Sizing within a range ideally from 1/4"" to 10 mesh in diameter.Dryer performance data is shown in Table 1. Capital costs between the two types of dryers are comparable with the Roto-Louvre producing generally a larger better-formed pellet. Dryer feeds differ in that at both Hardy and Fecunis, Ni-Cu concentrate filter cake is the only feed while at the Falconbridge slurry plant the dryer feed can consist of up to 10% by weight of smelter flue dust resulting in a combined concentrate-dust pellet for feeding to the Sinter Plant. To the Falconbridge Sinter Plant dryer, dust and limestone are added for the smelting process in addition to Ni-Cu concentrate."

Jan 1, 1972

By W. J. Witte, M. K. Witte

"INTRODUCTION A pilot heap leach project was conducted on the B. P. Selco Hope Brook ore located in southwestern Newfoundland. The pilot heap leach was undertaken to assess and confirm the following:1) To confirm that heap leach technology now currently used in the United States could be applicable to Canadian sites.2) To confirm gold recovery by the Heap Leach technology3) To assess and study potential heap leach environmental concerns in cold and wet climate.PROJECT LOCATIONThe Hope Brook Project is located near the southern coast of the island of Newfoundland, approximately 100 kilometers southeast from Stephenville, approximately 25 kilometers west of Burgeo, Newfoundland. Access to the property is limited to helicopter, float plane or by sea through Couteau Bay. The property was covered with muskeg and very few trees. Surface relief was moderate with many poorly drained boggy sections confined to small areas. Many small unnamed lakes were located on the property which provided water to small brooks and streams flowing to Couteau Bay.Several locations were reviewed for the installation of the pilot heap leach facility. Important parameters used to select a suitable location included sufficient land area, close proximity to but not on the ore body, reasonable protection from wind, sufficient supply of fresh water, close to a suitable location for a portable crushing plant, reasonable access to aggregate material for preparation of the test pad and ponds and suitable contours to minimize site preparation."

Jan 1, 1987

By Chris M. Healey

"The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from underground workings returned extremely high values, up to 12851 g/t (375 oz/T) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.In the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/T) gave extremely good results. In the third case, however, indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results.The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this data base, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

By K. Ski

Three series of membranes were prepared by blending polyvinylidene difluoride (PVDF) or poly(vinylidene difluoride-co-hexafluoropropylene) [P(VDF/HFP)] with sulfonated poly(ether ether ketone) (S-PEEK), sulfonated polysulfone (SPU), or sulfonated polystyrene, in order to develop novel PEM membranes suitable for melt processing. By means of incorporating fluorine-containing block copolymer into the blended system, acceptable proton conductivity and low water containing PEM materials were prepared. The effect of sulfonated poly([vinylidene difluoride-co¬hexafluoropropylene]-b-styrene) block copolymers as compatiblizers was investigated: conductivity was enhanced for S-PEEK/fluoropolymer blends. Microstructures for the blends were examined by transmission electron microscope (TEM) and scanning electron microscope (SEM).

Jan 1, 2005

By T. Navessin

Recent research activities in proton exchange membrane fuel cell (PEMFC) have significantly improved the performance per unit cost and its lifetime. These activities narrow the technology gaps, and thus, enable commercialization in some applications. One particular focus is in the development and understanding of proton conducting membrane materials. Many novel membranes are being developed which provide control and systematic understanding of complex relationships between chemical structure, morphology, physicochemical properties, and electrochemical kinetics. In this study, different classes of proton conducting membranes suitable for portable and automotive applications were evaluated in an operating PEMFC at the Institute for Fuel Cell Innovation, National Research Council. Analysis of these results may provide constructive feedbacks to the material researchers.

Jan 1, 2005

By J. Fournier

A novel sol ? gel (SG) synthesis procedure utilizing varying ratios of glycine and ethylene glycol to total metal cations has been developed to create high purity nanometer sized La0.65Sr3.5MnO3 powders. X-ray powder diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), and dynamic light scattering (DLS) have confirmed that the crystallite sizes of such powders are ~ 20 nm, and the aggregate particle sizes vary between 100 to 300 nm. Mixing varying weight percents of SG LSM powders with commercially available Praxair LSM in a composite LSM/YSZ functionally graded cathode has been shown, through the use of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), to exhibit enhanced oxygen reduction kinetics vs. at conventional cathode materials.

Jan 1, 2005

By E. W. Johnson

"The current increase in gold price may presage a resurgence of gold milling plants in Canada similar to that of the thirties. Because the industry has been at a low ebb for almost two decades, future operating responsibilities will likely devolve upon personnel with limited cyanidation experience. My comments, which may seem elementary to experienced operators, are directed towards these industry newcomers to highlight operational features in cyanidation which forty years' experience has shown me to 0e of importance. A brief review of what actually takes place in a cyanide circuit may help give a better understanding of the topics to be discussed.These will include: (1) expose the gold (2) dissolve the gold(3) make solid/liquid separation(4) recover the gold from solution.1. Expose the GoldThe chemical key to gold recovery by cyanidation lies in the ready solubility of the metal in a relatively weak solution (0.04%-0.075% NaCN equivalent by weight) of calcium or sodium cyanide. Obviously, dissolution cannot start unless the cya1ide is in contact with the gold. As an analogy, the yolk of a hard-boiled egg can oe taken to represent the gold particle and the egg white and shell, the surrounding gangue or sulphide host. As the sl1ell and white must be fractured to expose the yolk, similarly the surrounding gorngue or sulphide host must be broken or fractured to enable the cyanide solution to contact the gold."

Jan 1, 1979

By George Dogbe

Open pit optimization forms the basis of mine design, production planning and construction of mine facilities. The negative effects of this phase may include substantial reductions in ore recoveries, relocation of waste dumps and surface infrastructure, extraction of unwanted waste, with a cumulative effect on mine value reductions. As a result, this area has received significant research focus using linear and dynamic programming, heuristic, genetic and stimulation algorithms and the graph theory. These algorithms are derived from rigorous mathematical models, but they are built on the assumption that all the periodic production capacities are extracted at the time of analysis. This assumption weakens the models because mining occurs over significant time period. In order to develop a comprehensive model that accounts for the timing of material extraction, the current models, which are built on the economic block value (EBV) concept, must be modified to account for time. In this paper, the authors develop a model of the optimization problem using the 2-D Lerchs-Grossmann?s optimization algorithm. This model is used to investigate the effect of periodic discounting on the optimal pit layout design by designing an integrated pit optimiser (IPO) that incorporates ?production scheduling?. IPO uses the ensuing discounted economic block value (DEBV) as a basis for the pit optimisation process. The time-dependent model is compared with a time-independent model. The results show that discounting has no effect on the optimal pit contour although the reported pit value is overstated if the EBVs are used instead of the DEBV. The authors, however, believe that this conclusion may not be general and could have been influenced by the nature of ore body geometry and the proposed mining strategy.

May 1, 2004

By R. C. Bryce, G. S. Martin

"Aur Resources Inc. is the operator of the Louvicourt Mine located 40 km east of Val d'Or. Quebec. Les Entreprises Minieres Redpath Limitée a member of the 1.S. Redpath Group of companies was contracted to construct two vertical mine shaft collars in deep overburden.During the spring of1991 two vertical shaft collars were established in wet, running sand that was in excess of20 m deep. This paper will illustrate the engineering and construction techniques used in establishing these collars and the methods used to overcome the various obstacles that occurred during construction.IntroductionThe Louvicourt copper/zinc/gold/silver deposit is located 40 km east of Val d'Or, Quebec, is adjacent to the former Louvern Mine which operated at depths of 40 m to 850 m below surface (Fig. 1). This deposit was discovered in mid-1989 as the result of systematic exploration and diamond drilling based on a geological model. The Louvicourt project is operated by Aur Resources Inc.The property is being developed to produce 4000 tid with an anticipated life of just over 17 years. Mill start up is scheduled for July 1. 1994, commercial production October I, 1994, and full production by late 1995. The current production plan provides for 24 040 (XX) t averaging 3.89% copper, 1.95070 zinc, 0.039 oz gold per tonne and 0.99 oz silver per tonne, to be mined."

Jan 1, 1994

By A. E. Boudreau

Abstract-It has long been recognized that platinum-group-element (PGE) deposits in layered intrusions preferentially occur in intrusions that crystallized from high-Mg parent magmas. Recent studies suggest that evaluation of any given intrusion for economic PGE potential should also include assessment of the PGE, sulfur and chlorine concentrations in the cumulates and potential parent liquids. PGE: Magmas that contain relatively abundant Pt and Pd are the best candidates for forming economic deposits. Although analyses of coeval sills and dikes are the best indicators of primary magmatic PGE concentrations, analysis of the cumulates themselves is also valuable. For example, within the Stillwater complex, background PGE values in cumulates from the ultramafic sections of the complex contain, on average, several 10s of ppb Pt and Pd. Background concentrations of this order are suggestive that the magma was not depleted in the PGE. Sulfur: Conventional petrogenetic models for the formation of PGE deposits in layered intrusions require the PGE to have been concentrated during a magmatic sulfide-saturation event. In contrast, some hydrothermal models suggest that sulfur and the PGE were mobilized from footwall cumulates by upward- migrating, high-temperature hydrothermal fluids. Both models suggest that significant PGE deposits are likely to occur at and below the level where stratigraphic increases in whole rock sulfur concentrations occur. Chlorine: In both the Stillwater and Bushveld complexes the cumulate sequences below the major PGE-bearing zones contain anomalous Cl-rich apatite. The chlorapatite component of apatite in these rocks may exceed 40% and, in the Stillwater complex, typically exceeds 90%. It is stressed that pristine igneous mineral analysis and not whole rock data be used, as whole rock Cl concentrations may be affected by very localized (grain boundary), low-temperature alteration. Intrusions that crystallized from high-Mg, high-Cl magmas appear to have the best potential to host significant PGE deposits.

Jan 1, 1995

By Stephen G. Hardcastle

Worldwide, metal mines are going deeper. For example in Canada there are six such mechanized mines planning production at 3000m (10,000?). Working at such depths challenges all aspects of mining including the provision of ventilation to supply an equitable working climate for personnel and machinery. This paper explores the overall challenges of supplying ventilation in Canada?s deepest mines and how the volumes required could be minimized. This is essential because it must be remembered that ventilation and refrigeration are not only costly items to supply, but the magnitude of their cost is also very sensitive to the volume supplied. For ventilation this is obvious because of the cubic relationship between volume and cost. In deep mines, the main function of ventilation is the removal of heat transferred from the strata and generated by the mining machinery, and the air volumes supplied are designed accordingly. The second consideration is the removal of other pollutants that could be harmful to humans such as diesel and explosive fumes. However, the need for ventilation at its present design levels could be reduced. This paper discusses the implications of such technologies as: teleremote mining and alternatives to diesel equipment on the magnitude of the volume supplied; ventilation-on-demand which recognizes ventilation as a costly and limited resource; plus other aspects, such as the benefits of controlled recirculation, local cooling, and heat rejection back to the strata to gain further advantage from new developments. Furthermore, this paper advances the need to be able to design ventilation systems more cost effectively and how such new advances as process simulators can be used in conjunction with ventilation simulators to explore the diverse options that could affect the air volumes required and provide more realistic economic data upon which to base design decisions.

May 1, 2003

By Bing Li, Kai Liu, Yongcheng. Zhao

With the ongoing development of copper smelting technology, the improvement of environmental emission control and achieving an automated continuous copper pyrometallurgical process have become the key development goals for copper smelting. The double bottom blowing continuous copper smelting process combine bottom blowing smelting (SKS) and bottom blowing converting (BCC) process and fire refining as “three-connected furnaces” arrangement is a pyrometallurgical process independently developed by China’s ENFI which can continuously produce copper from raw material through to anodes. This technology can improve energy efficiency and reduce environmental emissions for the overall copper smelting and converting process. This paper discusses the engineering characteristics and production practice of the SDIC Jincheng Metallurgical Project, which operates SKS smelting and BCC converting process with “three-connected furnace” arrangement for the first time in the world. Advanced engineering concepts and tools were used to optimize the configuration during the project engineering stage. The operation shows that the process has good environmental performance, reduced energy consumption and high level of automation, which is a new choice for copper continuous smelting process. INTRODUCTION One of the most important developing trends for the overall copper smelting process is to develop a continuous operation. Continuous copper smelting can maximise energy efficiency in copper concentrate and make full use of the rich heat treatment system. Cold charge and a part of low-heat-generating materials, which are processing with additional equipment in traditional copper smelting process, can be processed with rich reaction heat in continuous copper smelting and converting process to achieve good economic benefits. Yuan and Wang (2017) noted that SKS+BCC copper smelting process can reduce the secondary SO2 emissions compared with discontinuous copper smelting process, which required transportation of melted matte by matte ladle and may cause secondary pollution. The continuous copper smelting process can also reduce the generation of intermediate cold materials.

Jan 1, 2019

By A. E. Boudreau

It has long been recognized that platinum-group-element (PGE) deposits in layered intrusions preferentially occur in intrusions that crystallized from high-Mg parent magmas. Recent studies suggest that evaluation of any given intrusion for economic PGE potential should also include assessment of the PGE, sulfur and chlorine concentrations in the cumulates and potential parent liquids. PGE: Magmas that contain relatively abundant Pt and Pd are the best candidates for forming economic deposits. Although analyses of coeval sills and dikes are the best indicators of primary magmatic PGE concentrations, analysis of the cumulates themselves is also valuable. For example, within the Stillwater complex, background PGE values in cumulates from the ultramafic sections of the complex contain, on average, several 10s of ppb Pt and Pd. Background concentrations of this order are suggestive that the magma was not depleted in the PGE. Sulfur: Conventional petrogenetic models for the formation of PGE deposits in layered intrusions require the PGE to have been concentrated during a magmatic sulfide-saturation event. In contrast, some hydro thermal models suggest that sulfur and the PGE were mobilized from footwall cumulates by upward-migrating, high-temperature hydrothermal fluids. Both models suggest that significant PGE deposits are likely to occur at and below the level where stratigraphic increases in whole rock sulfur concentrations occur. Chlorine: In both the Stillwater and Bushveld complexes the cumulate sequences below the major PGE-bearing zones contain anomalous Cl-rich apatite. The chlorapatite component of apatite in these rocks may exceed 40% and, in the Stillwater complex, typically exceeds 90%. It is stressed that pristine igneous mineral analysis and not whole rock data be used, as whole rock Cl concentrations may be affected by very localized (grain boundary), low-temperature alteration. Intrusions that crystallized from high-Mg, high-Cl magmas appear to have the best potential to host significant PGE deposits.

Jan 1, 1995

By M. Eikerling

The full competition between mass transport and reaction in PEMFC unfolds in cathode catalyst layers (CCLs). Recently developed models provide vital insights into effects of thickness and composition on effectiveness of catalyst utilization and performance. However, the CCL's key function in liquid water removal is rather unexplored. Studies of water balance in PEMFCs focus mostly on other cell components. Notwithstanding this prioritization, a simple calculation shows that the CCL is the PEMFC's favourite medium for conversion of liquid water into vapor. Porous structure and wetting properties steer the interplay of evaporation, transport and reaction. A model will be presented, that links pore space morphology, composition, distributed properties (concentrations, pressures, reaction rates, potential) with global performance (critical phenomena). It reveals how problems of flooding in the fuel cell could be mitigated by properly adjusting catalyst layer structure and operation conditions and under which conditions all liquid water arriving in the CCL would leave it as water vapour through the CCL/GDL interface. Results for a simple variant of the model emphasize the role of the CCL as a watershed for the whole cell.

Jan 1, 2005

By Kenneth Williamson

La découverte de nouveaux gisements métallifères constitue le point de départ du développement de l'industrie minérale. Or, au cours de ces dernières années, le nombre de ces découvertes a fortement diminué dans les territoires classiquement explorés, entraînant une recrudescence de l?exploration dans les terrains géologiques de grade métamorphique élevé (e.g., Province de Grenville, Grand Nord du Québec). Ces derniers ont été traditionnellement considérés comme stériles à cause (i) de la monotonie apparente des gneiss qui les composent, (ii) de la difficulté d?identifier leurs protolites, (iii) des changements importants dans l?apparence des gîtes recherchés reliés au fort degré de déformation et de métamorphisme et (iv) des théories qui prônent un lessivage important des cations et des métaux d?intérêt économique par les processus de déshydratation des roches lors du métamorphisme régional (Weaver et Tarney, 1985; Vokes, 2000). Cependant, l?avancée des connaissances dans la compréhension des gîtes métallifères et de leurs terrains hôtes gneissiques intensément métamorphisés, montre que les systèmes géochimiques des roches altérées demeurent robustes (p. ex. ; Trägårdh, 1991; Craig et Vokes, 1993; Geringer et al., 1994; Schandl et al., 1995; Zaleski et Peterson, 1995; Vokes, 2000; Blein et al., 2003, sous presse). Bien sûr, les sulfures peuvent être localement remobilisés et même fondre, mais cette remobilisation n?implique pas forcément la disparition du gîte hôte (Williams, 1990) et peut s?avérer, bien au contraire, bénéfique pour la rentabilité d?un gîte en augmentant sa teneur en minerais (Marshall et al., 2000). Jusqu?à présent, dans les terrains métamorphiques, les contextes sédimentaires et plutoniques ont été reconnus et respectivement explorés pour les gîtes de type SEDEX et les gîtes magmatiques de Ni-Cu. L?étude de gîtes de métaux de base et précieux intensément métamorphisés (faciès des granulites) et leur comparaison avec des gîtes équivalents peu on non métamorphisés a permis d?établir, au cours des dernières décennies, des outils pour l?exploration des terrains de haut-grade métamorphique (Vokes, 1991, 2000; Slack et al., 1993; Spry et al., 2000). Ces outils sont basés sur la reconnaissance de roches diagnostiques d?une circulation ou d?une exhalation de fluides hydrothermaux telles que les méta-exhalites (formation de fer, coticules, tourmalinites, roches riches en quartz-gahnite, en apatite, en barite ou en staurolite zincifère) (Spry, 2000; Spry et al., 2000). Ils sont utilisés constamment dans les ceintures supracrustales riches en roches métasédimentaires.

May 1, 2003

By X. J. Guo, Q. K. Wang, S. P. Zhong

With depletion of traditional clean copper reserves and fast expansion of the global copper demand and smelting capacity in the past decade, more and more copper smelters have to treat copper concentrate with increasing content of complex arsenic-bearing minerals. Developing economically viable and environmentally reliable methods and approaches for arsenic control in copper smelting has become more critical for sustainable growth of the copper industry. This paper will report the recent effort of Zijin Mining Group Ltd. in developing processes for improving arsenic control and management in the Zijin Copper Smelter. The arsenic distribution and balance data for matte smelting, converting and refining operations in Zijin Copper Smelter is reviewed for understanding of the current challenges in arsenic control. The processes developed for treating the arsenic bearing waste acid bleed stream from the smelting-converting off-gases wet cleaning circuit and the arsenic sludge produced in the refining electrolyte purification circuit for arsenic disposal are discussed. INTRODUCTION With fast expansion of the global copper smelting capacity to meet the world copper demand and depletion of traditional clean copper reserves, more and more copper smelters have to treat copper concentrate with an increasing content of complex arsenic-bearing minerals. China is the world largest copper consumer and also has the largest copper smelting and refining capacity, but majority of its smelting capacity relies on supply of imported copper concentrate. In order to meet the increasing copper demand and ease the tight supply of clean copper concentrate, the Chinese copper industry has to look at the domestic opportunity of developing non-traditional copper resources, specifically those of lower grades, more complex mineralogy, and increasing level of deleterious elements especially arsenic and also process imported copper concentrate with increased arsenic content. Due to a significant and growing environmental issue associated with arsenic contamination, developing economically viable and environmentally reliable methods and approaches for arsenic management and control in unlocking the maximum value of such arsenic bearing copper resources has become more critical for sustainable growth of the industry.

Jan 1, 2019

By L. C. Hsu, M. O. Desilets, P. J. Lechler, Jr. Bonham, J. G. Price, L. J. Garside

Geochemical background levels have been established for unmineralized sedimentary rocks that are elsewhere the hosts of Carlin-type gold deposits in the Getchell Trend. The Paleozoic rocks in the Winnemucca Quadrangle consist predominantly of the lower Paleozoicsiliceous and clastic sequences that were carried eastward along the Roberts Mountains thrust during the Late Devonian and Early Mississippian Antler Orogeny and the late Paleozoic Havallah and Pumpernickel sequences brought along the Golconda thrust eastward during early Mesozoic Sonoma Orogeny. Over 260 rock samples were collected from the Paleozoic sequences. Major and trace elements were determined by instrumental methods best suited for the specific elements. The general geochemical features of the Paleozoic sedimentary rocks are discussed in detail with reference to the data of average abundances of elements in sedimentary rocks. The background and threshold values of certain trace elements in sandstone, shale, and carbonate rock of one formation, as well as back-ground levels for the entire sequence were obtained. The characteristic geochemical features of the Paleozoic rocks in this area include: consistently high Ba and low Au contents (1.1 ppb, 1.5 ppb, 1.1ppb Au for average sandstone, shale and carbonate, respectively); generally low contents of those elements which may be of environmental concern such as As, Cd, Hg and Pb. Plots of major and trace elements suggest that the majority of the Paleozoic clastic rocks are related to a passive-margin tectonic setting. Samples with gold values higher than threshold are considered to have been affected by hydrothermal alteration related to gold mineralization. Most of these samples generally also have higher values of Sb, Hg, V and/or As. These observations support the use of such elements as pathfinders for gold, although V has not been identified as such before. Ba is not effective for gold exploration in this area due to the generally high background value of Ba, even though it may be an important pathfinder elsewhere.

Jan 1, 1995

By CIM CIM

Why Workplace Important! ?We need Diversity is to do more in the industry as a whole to encourage and support diversity. It has long been an industry of white dudes and we?re not going to survive if that?s how we continue to think.? ? Mark Scott, HR Superintendent, Vale Inco PURPOSE OF MINING FOR DIVERSITY ? Share best practices in the areas of HR Development ? Support industry in attracting, recruiting and retaining a diverse workforce ? Raise awareness of industry HR challenges and collaborate with stakeholders to develop sustainable HR practices

May 1, 2009