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By R. C. Urquhart

Since the first use of the electric arc furnace Henri Moissan (1892) and its use by Paul Hérholdt (1902) to melt steel, it has been successfully used as a pyrometallurgical smelting tool in the production of calcium carbide, iron, ferrous and non-ferrous alloys. Commercial forms of the electric arc furnace have evolved from round, single-phase single electrode units to rectangular three electrode three-phase units to round three electrode three phase units and ultimately to rectangular six electrode three-phase units. DC electrical supply has also been used to replace the three phase power supplies in some cases. This paper examines how these electric arc smelting furnaces have evolved in size, efficiency and configuration within the constraints of the smelting process, electrodes and electrical power supply equipment.

Jan 1, 2014

By R. J. Chase, C. Davies

"The Merelani graphite-tanzanite deposit is located in northeast Tanzania, 14 kilometers south of Kilimajaro International Airport and in close proximity to the towns of Moshi and Arusha. The graphite mineralization is hosted by relatively undeformed linear Proterozoic metasedimentary gneisses, several of which have been subjected to hydrothermal alteration resulting in tanzanite mineralization. Exploration work comprised detailed geological mapping coupled with pit and trench channel sampling and a subsequent 1500 meters of diamond drilling. In addition, metallurgical tests have shown the graphite to be of unusually coarse flake size, crystallinity and high purity.Feasability studies have shown the economic viability of a major coarse flake graphite deposit with the measured resource to 50 meters in excess of 9 million tonnes assaying over 85 graphitic carbon. Production is due to start by the end of the first quarter of 1994 with the processing plant design capacity initially set at 15 000 tonnes per annum.In addition to graphite production, tanzanite will be produced through selective mining within the graphite open pit in the upper horizon and from underground workings within the lower horizon.The Merelani graphite-tanzanite deposit will be the first major orebody to be exploited through means of private funding since Tanzania gained independence"

Jan 1, 1994

By D. W. McDonald, N. A. Duke, R. L. Hauser

"The NERCO Con Mine is situated in the amphibolite facies aureole of the Western Plutonic Complex overprinting the Yellowknife Greenstone Belt. Metamorphic grade of the upright monoclinal basaltic succession decreases from hornblende-amphibolite facies along the border of the batholith to greenschist facies. Metamorphic isograds, subparalleling the faulted margin of the batholith, transect volcanic stratigraphy and coincide with major goldbearing shears.Gold mineralization is confined to north-striking, west-dipping shear zones where hangingwall amphibolite facies mineral assemblages retrogress to chlorite-carbonate-sericite-sulfide bearing schists hosting multiple generations of quartz-ankerite veins. The gold-producing portions of the Con and Campbell Shears occur where these structures transect an east trending thermal corridor. The corridor is defined by granitic plugs and a number of related breccia bodies, that can be traced outwards from the batholith across the greenstone belt.Prograde reactions of greenstone during amphibolitization effectively liberate fluids that partition metals. With retrograde reactions at shear zones, gold is precipitated with quartz due to the destabilization of sulfide and arsenic complexes. The coupling of regional prograde metamorphic and restricted retrograde metasomatic overprints suggest mineralization is temporally related to emplacement of the Western Plutonic Complex. Economic gold concentrations within the intrusive corridor indicates enhanced metamorphic overprint of hornfelsed greenstones enveloping satellite intrusives peripheral to the main batholith."

Jan 1, 1993

By K. E. Waters, N. Brodusch, R. Gauvin, C. Teng, H. Demers

Rare earth elements play an increasingly important role in renewable energy devices and high-end electronics. In this project, the composition and morphology of REEs-bearing minerals are characterized with a field-emission scanning electron microscope at high spatial resolution and high counts rate using an X-ray silicon drift detector system. High spatial resolution imaging and energy dispersive X-ray microanalysis were applied at low and high magnification to obtain the composition of each phase in the minerals. From the standardless quantitative analysis results, the amount of REEs in each phase was measured and the relationships between those phases were identified.

Jan 1, 2014

By James F. Allan

"The Kipawa yttrium-zirconium prospect is located about 150 km south of Noranda, Quebec. Yttrium-zirconium mineralization occurs in an elongate, regionally metamorphosed and deformed peralkaline complex in the Grenville terrain. The mineralized zone, as defined by =.0.10% Y2O3, is 1300 m long and 10 m to 30 m wide. Zirconium content typically ranges from 0.50 to 1.20% ZrO2, The mineralized zone strikes northwest and dips 20 degrees to 35 degrees to the southwest. It occurs at the structural base of the peralkaline complex in syenite gneiss and calc-silicate rocks and is conformable with both the footwall contact of the complex, and the layering and gneissosity in the enclosing rocks. Minerals of economic interest are eudialyte (sodium-zirconium silicate), mosandrite (sodium-titanium silicate), britholite (calcium-silica phosphate), and a few other uncommon zirconium and titanium silicate minerals.The highest and most continuous yttrium grades occur in the upper part of the syenite gneiss unit in areas containing eudialyte, mosandrite and minor britholite. Yttrium also occurs in britholite in calc-silicate rocks and in mosandrite in syenitic rocks in the lower part of the syenite gneiss unit. Both the yttrium-bearing minerals and yttrium grades are erratic in the lower part of the unit. Zirconium is generally more uniformly distributed than yttrium. A peralkaline granite gneiss phase of the complex intrudes the syenite gneiss and possibly truncates it, and the mineralization, near the southern boundary of the mineralized zone.The mineralized zone is coincident with a radiometric anomaly and discontinuous yttrium and zirconium soil anomalies.More drilling and metallurgical studies will be required to determine the economic viability of the yttrium and zirconium mineralization at Kipawa."

Jan 1, 1992

By James F. Allan

"The Kipawa yttrium-zirconium prospect is located about 150 km south of Noranda, Quebec. Yttrium-zirconium mineralization occurs in an elongate, regionally metamorphosed and deformed peralkaline complex in the Grenville terrain. The mineralized zone, as defined by =.0.10% Y2O3, is 1300 m long and 10 m to 30 m wide. Zirconium content typically ranges from 0.50 to 1.20% ZrO2, The mineralized zone strikes northwest and dips 20 degrees to 35 degrees to the southwest. It occurs at the structural base of the peralkaline complex in syenite gneiss and calc-silicate rocks and is conformable with both the footwall contact of the complex, and the layering and gneissosity in the enclosing rocks. Minerals of economic interest are eudialyte (sodium-zirconium silicate), mosandrite (sodium-titanium silicate), britholite (calcium-silica phosphate), and a few other uncommon zirconium and titanium silicate minerals.The highest and most continuous yttrium grades occur in the upper part of the syenite gneiss unit in areas containing eudialyte, mosandrite and minor britholite. Yttrium also occurs in britholite in calc-silicate rocks and in mosandrite in syenitic rocks in the lower part of the syenite gneiss unit. Both the yttrium-bearing minerals and yttrium grades are erratic in the lower part of the unit. Zirconium is generally more uniformly distributed than yttrium. A peralkaline granite gneiss phase of the complex intrudes the syenite gneiss and possibly truncates it, and the mineralization, near the southern boundary of the mineralized zone.The mineralized zone is coincident with a radiometric anomaly and discontinuous yttrium and zirconium soil anomalies.More drilling and metallurgical studies will be required to determine the economic viability of the yttrium and zirconium mineralization at Kipawa."

Jan 1, 1992

By Denis Landry

"RÉSUMÉAu cours de dix dernières années, la compagnie Maghemite a développé, expérimenté et breveté un nouveau precédé de concentration du minerai de fer à partir de la récupération d'hématite présente au bassin de sédimentation de la Compagnie Minière Québec Cartier.A partir de cette nouvelle technologie de concentration par induction, la compagnie Maghemite produit une poudre d'hématite qui est mélangée avec du strontium carbonate à un ratio de l à 6 en poids. Le mélange homogène est achemine sur un disque d'agglomération, et ensuite incorpore dans la fournaise de la Compagnie Minière Québec Cartier. Le temps de cuisson et la température (l200°C) correspondent exactement aux critères nécessaires pour la fabrication d'aimants de céramique, Grade 5, à partir de la poudre de ferrite.IntroductionMeghemite a débuté sa production de poudre de ferrite au printemps 1986et prévoit une production de 20 000 tonnes par année dans cette nouvelle usine. A très court terrne, une usine sera construite pour la production de cinq à dix millions de Iivres d'aimants permanents par annee et à long terme qu'une usine de fabrication par robotique de moteurs à aimants permanents, utilises dans I'industrie automobile. La poudre de ferrite à base de strontium est une compose ferro-magnétique forme d'une molécule d'oxide de strontium et de six molécules d'hernatite. Ce compose d'hexa fluorite de strontium a une force tres puissante et fournit la source d'énergie magnétique la moins dispendieuse comparée aux autres aimants permanents. L'utilisation des aimants de céramique formes d'hexa fluorite de strontium a connu un croissance phenornenale depuis 1970 pour atteindre un marché de 500 millions de livres par année en 1985.II n'y a aucune autre usine de production commerciale de poudre de ferrite à base de strontium au Canada. Le facteur determinant qui a favorise l'etabilissement a Port Cartier est base sur la réduction de 30% du cout des aimants de cerarnique provenant de notre poudre. Notre debouche majeur se situe aux États-Unis et vise la production des aimants de cerarnique pour les moteurs utilises dans les automobiles, les ordinateurs et les appareils ménagers, L'objectif de cette compagnie est de réduire le prix futur des aimants de cerarnique à environ 30% du prix actuel.L'usine commerciale de production de poudre de ferrite est maintenant opérationnelle. Le financement et la construction de cette usine sont Ie résultat de l'opération d'une usine pilote sur une période de 5 ans afin de récupérer l'hematite d'un haut niveau de pureté provenant de résidus de I'usine de bouletage de la Compagnie Minière Québec Cartier (CMQC) à Port Cartier. La fournaise de CMQC est utilisee pour chauffer les boulettes cornposees d'un mélange de carbonate de strontium et d'hematite d'un haut niveau de pureté en étalant environ 5 tonnes à l'heure de ces boulettes au-dessus du tablier de boulettes de fer dans une des fournaises fonctionnant à environ 450 tonnes à l'heure."

Jan 1, 1987

By Glenn Ferguson

BACKGROUND Metals Risk Assessment at Contaminated Sites ? The field of metals risk assessment has advanced rapidly over the last five years ? Significant uncertainties and data gaps remain that require additional research if accurate assessments are to be conducted ? Research is being conducted by regulators, external institutions and academia ? Risk assessment practitioners are in need of answers or solutions TODAY

Apr 1, 2005

By Jianping Zhang

QUESTIONS: ?? Is it more expensive to find an ounce of gold in Canada today than 50 yrs ago? ?? Did the Canadian gold industry find more gold than they mined? ?? What is the future sustainability of the Canadian gold industry? ANSWERS: ?? The gold discovery costs in real terms only increased slightly from 1946 to 2000. ?? Though the Canadian gold industry mined more gold than they discovered in the period, when undeveloped deposits are taken into account, the deficit was merely 12 million ounces. ?? The Canadian gold mining industry would be sustainable in the foreseeable future, particularly, given the overwhelming predicted promising gold market in the mid/long run.

May 1, 2006

Some Statistics ? Feasibilitystudiescostbetween2% & 3% of capital andrequire8% to15% of total engineering effort ? Feasibilitystudiesusuallytakebetween8 and16 months ? Historically more than80% of projects fail to achieve all their objectives, usually blame the feasibility study ? What is bankable? Means that your promises will long be remembered. ? Poorly executed feasibility studies ? Driven by inexperience, unrealistic expectations, time constraints, financial constraints, lack of objectivity, front end loading activities incomplete or poorly done ? lack of minimum standard to provide a consistent approach Trend to improve???

May 1, 2010

By Jennifer L. Durocher

The speciation of Uranium in silica-rich depositional layers in the proximity to uranium ore deposits was investigated using micro X-ray fluorescence (VESPERS beamline), X-ray Photoelectron Spectroscopy, Laser-Ablation ICP-MS, Scanning Electron Microscopy, X-ray diffraction and micro-Raman Spectroscopy. The heterogeneous Si-rich laminations contain micrometer-size inclusions of secondary uranyl-minerals. The U concentration in these layers range from several ppm to lower weight percent and the U 4f spectra indicate variable U6+ : U4+ ratios. Correlation between the concentrations of U and other metals (M) suggests the presence of M-U-bearing nanoparticles or species within the amorphous silica matrix.

Aug 1, 2010

By L. Bichler, A. Siebert-Timmer

In this research, novel YSZ ceramics doped with 5 mol% Nd2O3 were manufactured via Spark Plasma Sintering (SPS) process. The sintered Nd2O3-YSZ ceramics were subjected to a static supercritical water environment at a temperature and pressure of 400 °C and 31 MPa, respectively. The weight loss and microstructure development of the sintered ceramic before and after exposure to supercritical water was studied. The results suggested that Nd2O3 addition significantly improved the degradation resistance of the YSZ ceramics. This was attributed to the improved phase stability of the 5 mol% Nd2O3-YSZ ceramics, since X-ray Diffraction (XRD) studies showed that the cubic stabilized matrix in these ceramics was retained after exposure to supercritical water. In comparison, pure YSZ ceramics exhibited a rapid degradation behavior as well as a phase change.

Jan 1, 2014

By Trung Nguyen

Midwest is a unique uranium deposit with exceptionally high arsenic content. The ore body is located 17km west of the McClean Lake operation. The McClean Lake mill will be modified to process Midwest ore and handle solid wastes coming from the Midwest water treatment plant. This paper describes the modifications required of the McClean Lake mill, process challenges associated with treatment of the arsenic, and the possibility of recovering nickel and cobalt as a by-product. It also reviews the complexity in the design of the Midwest water treatment facility which incorporates reverse osmosis technology with conventional physical-chemical water treatment.

Aug 1, 2010

By Steve Simard

Suite aux excellents résultats, obtenus avec la technologie des détonateurs électroniques dans des chantiers longs trous de grandes dimensions, nous avons décidé d?étendre cette technologie dans les ouvertures, dans le dynamitage de piliers et dans différents chantiers complexes. Cette technologie nous a permis d?effectuer l?abatage de chantiers avec un très grand nombre de trous sans détériorer le terrain. L?équation est bien simple avec les détonateurs électroniques, plus gros sont les dynamitages moins de fois les épontes se font ébranler, moins de blocs d?effondrement se retrouvent dans les points de soutirages entre les dynamitages et plus la fragmentation est meilleure. La flexibilité d?opération que nous avons obtenu avec les détonateurs électroniques est difficilement quantifiable, mais elle nous a permis de maintenir notre rythme de production mensuelle même avec certains chantiers complexes. Il est bien certain que l?utilisation des détonateurs conventionnels a encore sa place dans une mine conventionnelle comme Beaufor, mais l?utilisation des détonateurs électroniques a aussi sa place dans certaines situations spéciales. Pour terminer, bien que la technologie des détonateurs électroniques soit encore dispendieuse, nous pensons encore l?utiliser pour optimiser certains dynamitages et ainsi maintenir notre flexibilité d?opération.

Oct 1, 2004

By Robert Bégin

Reconnue pour son expertise en formation minière, la Commission scolaire de l?Or-et-des-Bois, dans le cadre du projet MRN-ACDI en Bolivie, a reçu en 1999 le mandat d?implanter un programme de formation en santé et sécurité du travail dans les mines artisanales boliviennes. À la suite d?une mission préliminaire en Bolivie et de la venue à Val-d?Or d?une délégation bolivienne, il a été convenu de l?adaptabilité du modèle québécois du programme de «formation modulaire du travailleur minier» au contexte bolivien. Là-bas, les méthodes de travail sont essentiellement artisanales et la pauvreté extrême des mineurs les pousse à prendre des risques quotidiens. Les modules de formation priorisés sont : «Introduction à la santé et à la sécurité du travail», «Principes d?écaillage» et «Matériel de sautage et explosifs». Les universités Tomas Frias de Potosí et Siglo Veinte de Llallagua sont responsables de l?élaboration et de l?implantation du programme dans deux coopératives minières de leurs secteurs. Dans une phase ultérieure, le programme sera étendu à plus large échelle. Enfin, des missions de suivi et d?encadrement sont effectuées périodiquement par les représentants de la Commission scolaire de l?Or-et-des-Bois. La formation en santé et sécurité dans le milieu de travail constitue un nouveau défi pour les universités boliviennes et une source d?espoir pour les mineurs des coopératives minières.

May 1, 2001

By Peter A. Witt

Highland Valley Copper is a conventional truck-shovel mining and flotation concentrator operation located some 75 kilometres southwest of Kamloops, B.C. (Figure 1). The ore is located within a porphyry copper deposit and is mined at a rate of 135,000 metric tonnes per day from two separate open pits. The nearby mill produces concentrates containing 375 million pounds of copper and 5 million pounds of molybdenum metal yearly. In the Valley pit, head grades are roughly 0.40% Cu at a 0.23% Cu equivalent cut-off. The Valley pit strip ratio currently sits at 0.55:1 with waste quantities made up of separate rock and unconsolidated overburden units. From the mill, concentrates are trucked to nearby Ashcroft and then hauled by rail to ocean port facilities in Vancouver. The mine employs 950 persons and is planned to operate until 2009. The operation is a partnership between TeckCominco with a 63.9% interest, BHP Billiton holding 33.6%, and others 2.5%. Management is shared by the two principal owners and directed by a management committee.

May 1, 2003

By M. Maeda, H. Sasaki

Dissolution characteristics of metals vary significantly when they form alloys with other elements. Because hydrometallurgical processes are essential in separation and refining of non-ferrous metals, it is important to study behaviors of alloys in aqueous solutions. The authors have studied dissolution characteristics of precious metals in acid solutions using electrochemical measurement. When precious metals are alloyed with Zn, its dissolution is promoted by an increase in surface area caused by the preferential dissolution of this metal. The electrochemical study also revealed that precious metals dissolved from some alloys at unusually negative potentials; the underpotential dissolutions are explained by activations of these metals in the dealloying.

Jan 1, 2014

By Peter A. Witt

Highland Valley Copper is a conventional truck-shovel mining and flotation concentrator operation located some 75 kilometres southwest of Kamloops, B.C. (Figure 1). The ore is within a porphyry deposit and is mined at a rate of 135,000 metric tonnes per day from two separate open pits. The nearby mill produces concentrates containing 375 million pounds of copper and 5 million pounds of molybdenum metal yearly. Head grades are roughly 0.40% Cu at a 0.23% Cu equivalent cut-off. The strip ratio currently sits at 0.55:1 with waste quantities made up of separate rock and unconsolidated overburden units. From the mill, concentrates are trucked to nearby Ashcroft and then hauled by rail to ocean port facilities in Vancouver. The mine employs 950 persons and is planned to operate until 2009. The operation is a partnership between three owners: TeckCominco (61.4%), BHP Billiton (33.6%), and Highmont Mining (5%). Management is shared by the two principal owners and directed by an appointed committee.

May 1, 2002

IBI Alliances ? Government ? People ? Academic ? Associations ? Media ? Customers ? Agencies ? Shareholders ? Industry consultants ? Investment Authority ? Geological Survey ? Department of Mines ? People ? Local Residents ? Mineworkers ? Academic ? University of Guelph ? Uganda Vermiculite Institute ? Associations ? TVA ? Organic Certification ? Media ? Canada ? International ? Customers ? Advocacy role ? Agencies ? Regional International

May 1, 2006

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