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By G. Portillo

Electrospark Deposition (ESD) is a pulsed-arc micro-welding process characterized by using high current electrical pulses, of a short duration, to deposit an electrode material on a metallic substrate. The short duration of the electrical pulse allows for a low heat input over the substrate and an extremely rapid solidification of the deposited material. As a result, the ESD is capable of a wide variety of microstructures like micro-segregationfree solid solutions, nanostructured grains, metastable structures, and amorphous phases. The present work shows a microstructural analysis of rapidly solidified Al-Ni alloys coatings by the ESD process. Field Emission Scanning Electron Microscopy (FE-SEM) and X-Ray Diffraction (XRD) were performed to present the microstructural evolution as a function of the welding parameters. The phases and non-equilibrium metastable structures present in the alloys, and their distribution, were found to be a sensitive function of the alloy composition; hence its formation is governed primarily by thermodynamic considerations.

Jan 1, 2011

By L. W. F. Mackenzie

The influence of rolling temperature and annealing on the recrystallization and texture of magnesium AZ31 has been investigated. 100x125x6 mm AZ31 plate was cast in a permanent steel mould and then homogenized at 380°C. As-cast and homogenized microstructures were then characterized, and 35x30x6 mm specimens were machined from the homogenized material. Specimens were rolled up to 40% at temperatures between 25 and 350°C; selected specimens were subsequently annealed at 400°C. Following rolling, the microstructures were compared. The influence of rolling temperature on as-rolled texture has been demonstrated, and texture evolution has been evaluated following annealing. The recrystallization behavior has also been characterized. Optical microscopy, scanning electron microscopy and electron backscattered diffraction (EBSD) were used to characterize the microstructures of the alloys. X-ray texture analysis was used to investigate the texture in as-rolled and annealed specimens.

Jan 1, 2006

By R. Farhat

Coating systems that yield a thermally grown oxide (TGO) protective layer have been proposed as a potential method for extending the lifecycle of components exposed to high temperature corrosion. This is particularly relevant to the petrochemical industry, where any reduction in corrosion rates can yield substantial cost reductions. The primary goal of this project is to develop a coating repair procedure and to investigate the oxidation performance of the repaired location. Electrospark deposition (ESD) was used to repair spalled segments of TGO grown on MCrA1Y substrates using various electrodes possessing mixed crystal structures. Specifically, electrodes of NiCoCrA1Y (BCC-FCC mixtures) and CoNiCrA1Y (FCCBCC mixtures), were deposited and oxidized to develop the TGO using a heat treatment of 24 hours at 1000°C in air. This presentation will focus on the microstructural evolution of the base metal and ESD repair on damaged area, in both as- deposited and oxidized forms. Results of SEM and XRD analysis will be presented.

Jan 1, 2011

By Christoph Mueller

?Globalization and the impact on mine operations? is one of the themes of the 2003 annual CIM meeting. Global mining business in practice always means to act with local base material resources in order to reach the mining company?s global business goals. On the other hand these operations are characterized by cost pressure and cycling product prices. Driven by actual prices, local product markets and local production cost, one time one mine can be most efficient while under different circumstances another mine will be the most efficient producer for the same customer [PENSWICK, 2001]. Therefor in the future the most profitable mining companies will be those who have permanent ?real-time? control on their actual production cost level. Certain approaches are under way to provide reliable modeling tools for aiding mining companies in highly complex decision finding procedures. A high potential for enhancing efficiency is the integration of all single steps of the mining working chain into a production process structure to make advantage of an optimized flow of material and information through the ?moving ore factory? [WIGDÉN, 2001]. Crucial to all these activities is the ability of getting reliable, just-in-time information from the entire mining production chain. As modern mining machinery today is controlled electronically and even already operated autonomously, the theoretical preconditions for the data acquisition is already fulfilled. But up to now, there was no way of cost effectively exchanging the process information with databases, simulation tools and other enterprise level software. Any data exchange problem had to be solved by individual and expensive software development projects. To solve these problems, the International Rock Excavation Data Exchange Standard (IREDES) was launched in 2000 by major players in the industry. The task of this initiative is to define a ?common electronic language? for easy and standardized data exchange between mining machines and central computer systems. As in other industries, this standard is expected to have significant impact on the use of automated equipment. It shall provide easy ways of using multi vendor machine installations in data controlled mining processes. At the same time it reduces cost for individual development of interfaces for all parties involved. The standard?s technical architecture is flexible and open - also for future applications. It uses modern technology enabling easy data exchange with commercial databases as well as open on line networking.

May 1, 2003

NANA Accepts Mining ­ 1974 - Leadership presented mining option to people ­ Community meetings; recognized need for cash economy ­ 1979 - Poll shows consensus in favor of mine development ­ 1980 - Shareholders approve mining; Congress approved land selections

May 1, 2002

By Arnold R. Miller

Overview ? Vehicle Projects LLC (prime contractor) and the Fuelcell Propulsion Institute have developed the world?s first fuelcell locomotive. ? Principal applications are underground mining and tunneling. ? Because fuelcell vehicles solve the problem of underground emissions, mining is expected to be their first commercially viable market. ? The first year of a three-year project to develop a fuelcell mine loader is funded and underway.

May 1, 2002

By Dennis Martin

What is Borehole Hoisting Borehole Hoisting is the use of a hoisting plant to hoist rock, workers and materials or both, vertically through a borehole, between a mine level and surface or between two levels of an underground mine. Screen and bolt ground support on walls of 5.5 m diameter borehole hoisting shaft

May 1, 2013

By BARRY BANNATYNE

About 90 per cent of Manitoba's industrial minerals production is for structural materials. Most of these come from the Paleozoic rocks west of the Precarnbrian Shield, or from glacial deposits that are extensive throughout Manitoba. The major raw materials are sand and gravel, and carbonate rocks for crushed stone (and also dolomite for high-magnesia lime, high-calcium limestone for lime and Portland cement, and dolomitic limestone for Tyndall stone). Glacial lake clays are used both in cement and in lightweight aggregate. The Jurassic and Cretaceous strata exposed along or near the Manitoba Escarpment include siliceous, carbonaceous, kaolinitic and illitic shales, all of which are quarried by Red River Brick and Tile in the Pembina Mountain and Ste. Rose areas for use in a brick plant at Lockport. Non-swelling bentonite near the base of the Pembina Member of the Upper Cretaceous Vermilion River Formation is of value as an absorbent clay, and is the only commercial source in production in Canada. It has been quarried by Pembina Mountain Clays Limited since 1940. Gypsum occurs in the Jurassic Amaranth Formation and supplies much of the market for wallboard and Portland cement additive in the Prairie Provinces. Quarries are operated at Gypsumville by Domtar Construction Materials Limited, and north of Amaranth by Westroc Industries Limited. Silica sand from the Ordovician Winnipeg Formation is of glass-grade quality, and about 100,000 tonnes are produced annually by Steel Brothers Canada Limited on Black Island . It is used as a glass sand, as foundry sand, for sand blasting, and as a filter-bed sand .

Jan 1, 1984

By Victor Dolmage

"The localization of orebodies by geological structures is well demonstrated at the Copper Mountain mine of southwestern British Columbia. These extensive deposits; owned and workd by the Granby Consolidated Mining; Smelting and Power Company; are at Princeton; abo!lt 150 miles east of Vancouver and 40 miles north of the International boundary. The geology of the deposits and the surrounding district is described by the present writer in Memoir 171 of the Geological Survey of Canada; pub1ished in 1934.The main geological feature is a gabbro stock, elliptical in plan, with a major axis about 5 miles in length extending in a northwest-southeast direction. The stock varies in composition from syeno-gabbro (gabbro plus orthoclase) through diorite and syenite to a core of syenite pegmatite. All the members contain orthoclase, which ·increases greatly in amount toward the centre, but all are devoid of quartz. The stock has been injected into a steeply folded series of volcanic flows, breccias, and tuffs that strike more or less parallel with the major axis of the stock. On its northeast side the stock is flanked by a band of fairly coarse volcanic breccia of andesitic composition and ·having fragments up to several inches in length. Where this breccia is tangential to the stock it is both dynamically and chemically metamorphosed to a marked degree, and within the zone of this metamorphism are enclosed the copper deposit~. The ore consists of bornite, chalcopyrite, and a little magnetite occurring as disseminated grains and small veinlets in the metamorphosed breccias. The only gangue minerals are orthoclase, albite, oligoclase, and biotite. The two most common vein minerals, quartz and pyrite, are conspicuously rare or absent. The dynamic metamorphism has produced two well-defined structures, namely, a strong schistosity parallel with the curved vertical contact of the stock and a very striking set of small, straight, nearly parallel open fractures that stand nearly vertical and at right angles to both the schistosity and the stock contact. These are called the ore fractures."

Jan 1, 1954

By John S. Stevenson

"Although we have no uranium- producing mines as yet in British Columbia, uranium, associated with gold and cobalt, has been found in two deposits in amounts such that the combined value of the metals not only warrants the further exploration of these deposits, but also encourages the search elsewhere in the Province for other similar deposits.Where uranium-bearing veins have been found in British Columbia, the uranium mineral is the crystalline variety of uranium oxide, uraninite, rather than the massive, non-crystalline variety, pitchblende, such as found in the Great Bear Lake deposit and in other similar deposits along the southwestern margin of the Precambrian shield.The principal occurrences of uranium known so far in British Columbia are associated with bodies of granodiorite and quartz diorite along the eastern side of the Coast Range belt of batholiths. In this part of the Province, interesting amounts of uranium occur on the Gem property in the Bridge River area and on the Victoria property south of Hazelton; and smaller amounts occur on the Red Rose, Rocher Debouze, Delta, and Ohio properties, also south of Hazelton. At the Gem and the Victoria, the uranium mineral, identified as uraninite, occurs in deposits that also contain abundant cobalt-nickel sulpharsenides, and molybdenite.At these properties, the uraninite occurs as clusters of small black crystals of sub-metallic lustre that may be seen upon careful -searching of a highly radioactive specimen with a hand lens. Under the microscope, the uraninite is seen to be in the form of cubes or modifications of cubes that may occur as individual grains widely scattered throughout the gangue or may be gathered into clusters of several grains. The grain size of the uraninite is in general small. Although a few clusters of grains are up to about 10 mesh in diameter, the individual grains, whether in clusters or widely disseminated, are rarely more than 400 mesh in diameter."

Jan 1, 1950

Toronto 2013 Proceedings

May 1, 2013

By Andreea Catalina Gluhoi

The oxidation of propylene and methane has been investigated over two series of Au/MOx/Al2O3 and Au/MIOx/MIIOx/Al2O3 catalysts (M, MI, MII =Li, Rb, Mg, Mn, Ce, Zr). Whereas the effect of the presence of MOx or MOI x/MOII x on the oxidation of methane is relatively small, a large enhancement in activity is observed for propylene oxidation. Synergistic effects have been observed by combining ceria or a transition metal oxide (high oxygen storage capacity) with an (earth) alkali metal oxide.

Oct 1, 2003

By Renaud Cousin

Supported gold catalysts were prepared by Direct Anionic Exchange on an alumina support and tested during the reaction of CO oxidation and of saturated and unsaturated hydrocarbons (C1 to C3). The catalysts showed high activies over a range of concentrations and temperatures compatible with an application to automotive exhaust cleaning. Furthermore, a complete resistance to thermal ageing at 600°C in the absence or presence of water was observed due to the obtention of strongly anchored nanosized gold particles during the preparation step.

Oct 1, 2003

By Brian Putland, Fred Kock, Leigh Siddall

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012

By Fathi Habashi

Teaching mining, metallurgy, and geology preceded that of the other engineering disciplines. The first School of Mines was founded in 1756 in Potosi (Fig. 1) in New Spain (now Bolivia), 38 years before the first Polytechnic School (École Polytechnique) was founded in Paris. The schools of mines were also pioneers in the teaching of chem- istry. The teaching staff at these schools cre- ated the basic literature on metallurgy, mining, and geology. They analyzed and dis- covered numerous minerals and discovered the metals tungsten, beryllium, chromium, uranium, zirconium, vanadium, indium, and germanium. The history of some of the first schools is given together with biographies of some of their distinguished teaching staff.

Nov 1, 1997

By Jucheng Wang

Unplanned open stope dilution is a major cost factor for many mining operations, even though significant advances in empirical and analytical approaches for estimating stope dilution have been made. Many factors that influence hanging wall dilution are still either ignored or assessed in purely subjective terms. Undercutting the stope hanging wall on both the overcut and undercut development are well recognized factors which contribute to hanging wall instability and dilution. In many mines, undercutting the hanging wall breaks the integrity of the rock mass that may form along continuous foliation or bedding planes parallel to the stope hanging wall contact, reducing stability. This undercutting also increases the zone of destressed or relaxed rock that may potentially fall into the open stope as dilution. An approach is introduced for quantifying the effect of undercutting on potential stope dilution. An extensive database of stope case histories has been collected to look at dilution from Hudson Bay Mining and Smelting operations (HBMS) in Flin Flon.

May 1, 2002

By Robert Lamarre

We will present the summary of a number of case studies whereby mining organizations have succeeded in maximizing equipment uptime by reducing the number of maintenance parts stock outs by more than 80% while scaling down total inventory maintenance parts by more than 20%. We will present a thorough comprehensive methodology to improve business processes in order to optimize inventory management and forecasting. We will examine: ? Demand management optimization ? Forecasting organization ? Inventory management parameters optimization ? Improved replenishment processes ? Inventory optimization and the right KPIs and exception reports We will provide cases in point such as Areva in Africa, Cambior (IAMGOLD) in South America, Osisko Mining Corporation, Barrick Gold/Bousquet Mine and Aurizon Mines Ltd./Casa Berardi in North America. We will discuss how Inventory Management World Best Practices operates in a maintenance environment. We will present how an integrated approach, coupled with a strong Enterprise Asset Management or CMMS system with an Inventory Optimization system specially designed to manage spare parts, actually promises and delivers results.

Nov 1, 2011

By Jerry Danni

In order to remain viable today, corporations must view the environment as a strategic issue, and integrate environmental management throughout the organization. Corporate programs that used to be based primarily on regulatory compliance now must emphasize strategic environmental management systems, and must integrate these environmental systems with basic business functions. The mining industry today is global, and must have an organizational structure that can embrace different cultures, physical settings, and regulatory regimes. Sound environmental management practices are not different from good management principles. An effective environmental management system should be a complementary system to an organization?s overall management framework, integrated and aligned with the existing management structure. Integrating environmental management into core business functions is just good business. An effective environmental management system is a critical component of a company?s commitment to environmental, social and economic accountability. This paper presents the elements of the Kinross Gold Corporation strategic environmental management system and discusses the integration of the environmental management system into the core business functions throughout the Company

May 1, 2003

By Jacek Paraszczak

As the deposits located closer to the surface are getting depleted, more and more Canadian mines produce ore from considerable depths. Deep mining represents a number of serious challenges including high rock temperature. Conventional diesel powered loadhaul- dump machines and trucks so widely used in metal mines constitute an additional source of heat and noxious gases. Due to this, they have a substantial adverse impact on a quantity of fresh air required and a cost of ventilation, particularly since the mines have to meet more and more stringent regulations in this respect. In this context, the paper examines possible alternatives for diesel powered equipment, both these commercially available as those at the stages of prototypes or under development. They are reviewed with regards to their principles, required infrastructure, stage of technology development and its progress. The questions of their flexibility, practicality and economic viability are also addressed. Following the above a potential for their implementation and possible benefits (if any) in the conditions of deep Canadian mines is discussed. The paper concludes with short to medium term predictions concerning the most promising drive alternatives for vehicles destined to operate in deep metal mines.

Feb 1, 2008

By S. C. Bouffard

Barrick's Zaldivar operation in Chile produces copper by heap leaching, solvent extraction, and electrowinning. The heap consists of a dynamic pad, and its stacking and operating conditions have changed over its 11 years of operation. These changes have included pad re-mining midway through the cycle, tightening of the irrigation drip lines, an increase of the coarseness of the particles, and an increase of the heap height. This paper reviews the heap operating data to understand the effects of these changes on the kinetics and recovery of copper minerals. Field tests demonstrated that neither re-mining nor tightening the irrigation grid added value for both low and high grade oxide and sulfide ores. The P80 of the feed ore was increased by 0.8 mm, which did not reduce the copper recovery of oxide and sulfide ores. The increase of the heap height above 8 m lowered moderately the copper recovery from sulfide minerals, and very slightly the recovery from oxide minerals. Despite the lower recovery, the higher tonnage stacked in the taller heap increased the copper output. Optimizing the chemistry of the agglomeration and feed solution holds more promise for increasing the copper recovery than the above physical changes.

Jan 1, 2007