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By G. Goodall, D. Mercier, M. Brochu, C. Kaplin

A nanostructured CoNiCrAlY coating was obtained by thermally spraying cryomilled feedstock powder using the high-velocity oxy-fuel (HVOF) process. The oxidation behavior of the nanostructured powder and coating were compared to their conventional counterparts by performing static oxidation tests at 1000°C for durations ranging from 1 to 96 hours. It has been found that oxidation of the conventional powder yielded a duplex oxide scale composed of an inner layer of Al2O3 and an outer layer composed of Cr2O3, NiAl2O4 and other spinels. Interestingly, oxidation of the as-sprayed nanostructured coating yielded a similar duplex oxide scale while oxidation of the polished coating resulted in a single Al2O3 layer. These findings indicated that surface oxide seeds act as nucleation sites for the growth of the mixed oxide layer. Also, it was determined that nanostructuring of the coating promotes the nucleation and growth of a single and adherent a-Al2O3 layer by increasing both the number of diffusion channels and the aluminum concentration at grain boundaries.

Jan 1, 2010

By M. M. Williams

ALBERTA has been generously endowed with oil, natural gas, coal and water power, thus giving power producers a wide choice in the type of plant and fuel which can be used. Therefore, with such a variety of energy sources to choose from, why was coal selected as the primary fuel at Calgary Power's Wabamun steam plant? This part of the paper will cover the circumstances that led the Company to decide in favour of coal. The second part, to be presented by C. F. Doerr, will describe how the Wabamun coal mine has been developed to supply the large fuel requirements of the power plant. Before considering the Wabamun plant, we require a general under-standing of? the Company's electric system and load. Power is fed into a 5,100-mile high-voltage transmission grid from eleven hydroelectric plants and from the Wabamun steam electric plant. These plants have a combined generating capacity of 820,000 horse-power. Of this total, the hydro

Jan 1, 1963

By G. A. Frame, J. G. Patterson

The 24,000-tpd Frood-Stobie mill grinding circuit operation and control are described. Changes implemented during the past three years to improve grinding efficiency and capacity are discussed.

Jan 1, 1971

By W. S. (Steve) Vaughan

The Origins of Joint Ventures in Canada?s Mining Industry ? Among the most important financing structures used in our mineral industry today ? Virtually unheard of in the Canadian industry prior to the 1970s ? Borrowed from the U.S. oil and gas sector where it came into prominence in the late 1930s ? The Securities Acts of 1933 and 1934 in effect killed the sale of (equity) shares for financing oil and gas wells and start up mining companies

May 1, 2013

By J. B. Evans

"NORMALLY the duties of the exploration engineer and geologist cover the initial, and possibly, the most important phase of mining property evaluation; that phase being the presentation of an opinion of the property's ore reserve potential in terms of tonnage and grade. The prime objective of this pa-per is to outline one method of bridging the wide gap that lies between a know ledge of a property' s tonnage and grade potential and an appreciation of the value of that property in dollars and cents.THE PRESENTATION OF PROPERTY EVALUATIONThe engineer engaged on a mining property evaluation, regardless of whether he be an independent consultant, or a company employee, has as his goal, the presentation of his appreciation of the property's potential value or worth within terms of reference acceptable to his principal.To furnish a complete evaluation report, the evaluator must firstly study all aspects pertaining to the particular property under consideration, then present his appreciation of the property's worth in some tangible form. The ultimate presentation is one giving a Present Value of the pro pert y in terms of monetary exchange. Such an idealistic presentation is not always possible; typical preventives being -insufficient reliable information, limited time, Jack of ability and absence of definite direction."

Jan 1, 1960

By R. O. Grieve

"IntroductionCALEY (1945) and Evans (1950) pointed out that certain instances of convergence between Devonian and Silurian horizons, frequently evident in wells drilled for oil and gas in Ontario, appear to be related to local thinning of salt beds in the Salina formation and they suggested that leaching of the salt beds may have occurred. Exploratory drilling by Imperial Oil Limited since 1945 has brought to light several examples of structures similar to those discussed by Caley and Evans. The writer has had the opportunity to examine cuttings and data from wells which penetrated these structures and the attempt to interpret them in the light of the theory of leaching and subsidence proposed by Landes ( 1945a) to explain the marked brecciation and deformation of Upper Silurian and Middle Devonian sediments which crop out in the Mackinac Straits region of northern Michigan has led to the observations presented in this paper."

Jan 1, 1955

By T. C. WEBB

In New Brunswick, significant potash deposits are intimately associated with rocks of the Lower Carboniferous Windsor Group. To date, two deposits high in sylvinite, up to 20 m thick, have been confirmed at depths between 490 and 1,035 m below surface near Plumweseep and Salt Springs. These areas are currently under development by the Potash Company of America and the Denison-Potacan Potash Company respectively. A third area, near Lower Millstream, is also known to contain potash-bearing evaporites and is now being explored by BP Exploration Canada Ltd. All three areas are situated in the western half of the Moncion Subbasin and are within 25 km of Sussex. Numerous similarities in stratigraphy, thickness, mineralogy and structure suggest that deposition of evaporites throughout much of southern New Brunswick was contemporaneous and extended over a considerable area. Future opportunities for potash exploration in the province thus seem excellent. A number of large unexplored areas remain in the Moncion and Cumberland Subbasins and in parts

Jan 1, 1984

By K. Sugawaral, W. Tongampl, K. Hiruta, Takasaki Y., A. Hosoi, T. Katol, A. Shibayamal

Printed circuit boards of discarded personal computers, televisions, mobile phones and so on contain a significant amount of valuable metals. For the recycle of valuable metals contained in the printed circuit board wastes (P CB W), the effect of temperature on chlorination-volatilization of metals under chlorine gas flow was studied. The experimental sample used was powder of two types: crushed PCBW (Sample 1) made from PC and industrial machines, and crushed-combusted PCBW (Sample 2) made from Sample 1. The principal element in Sample 1 and Sample 2 was copper, about 13 wt% and 20 wt% respectively. Sample 1 was composed of pure metals such as copper, tin and lead. In comparison, Sample 2 consisted of oxide metals such as copper oxide, tin dioxide and silicon dioxide. The two samples were heated at predefined temperatures (ranging from 300 °C to 900 °C) in chlorine gas. The chlorine gas flow into the furnace was set at a rate of 100 mL/min. As a result, copper in Sample 1 began to volatilize at 600 °C and completely vaporized at 700 °C. While in Sample 2, copper started to volatilize at 600 °C and reached 100% vaporization at 800 °C. For Sample 1, zinc finished volatilizing at 500 °C, while for Sample 2, zinc volatilization reached only about 80% (maximum). Also, lead, nickel and titanium showed similar results. Consequently the volatilization rate of Sample 1 is higher than Sample 2 and the temperature dependency was verified for copper, lead, zinc, nickel, antimony, titanium and chromium. In fact, the volatilization rate of these metals increased with the temperature. This result reflects the difference between pure metal and metal oxide, as Sample 2 was combusted before the chlorination-volatilization test. Moreover, the chlorination reaction may be accelerated by a reductive atmosphere because Sample 1 contains carbon. In this study, the volatilization behavior of some valuable metals in PCBW by chlorine gas was observed. Further improvement in the rate of volatilization can be achieved by optimizing the experimental conditions.

Jan 1, 2011

By Chuan-Jian Zhong

Gold-based nanoparticles in the size range of a few nm have attracted increasing interests in catalysis, sensors and biomedical applications. The study of the unique catalytic properties of nanosized gold was inspired by the pioneering work of Haruta on the nanogold-catalyzed CO oxidation (1-4). There have been a number of excellent reports discussing both fundamental and application aspects of gold nanoparticles in catalysis (3-8). Our work reported herein is aimed at investigating the preparation and application of gold and its alloy nanoparticles for potential applications in fuel cell catalysis. Fuel cells operating by electrochemical oxidation of hydrogen or methanol fuels at the anode and reduction of oxygen at the cathode are attractive power sources due to their high conversion efficiencies, low pollution, lightweight and high power density. While methanol offers the advantage of easy storage and transportation in comparison with hydrogen fuel cell, its energy density (~2000 Wh/kg) and operating cell voltage (0.4 V) are much lower than the theoretical energy density (~6000 Wh/kg) and the thermodynamic potential (~1.2 V). The poor activity of the anode catalysts and inefficient activity or issue related to "methanol cross-over" at the cathode electrode are associated with the loss of about one-third of the available energy at the cathode and the other one-third at the anode. Extensive studies have been focused on Pt-group metals (Pt+Pd+Rh+Ru+Ir (PGM)) for both anode and cathode catalysts. A major problem is the poisoning of Pt by COlike intermediate species (9,10). Recently, oxide-supported gold nanoparticles in the <10 nm size range have emerged as one of the best catalysts for CO oxidation (1-3,11), and for water gas shift reaction in reforming stage using 5 nm Au on Fe2O3 (6). Gold and its alloy with other metals in the nanosize range present new alternatives (2,12). Whether the unique properties of gold nanoparticles can be exploited for addressing these problems is a focus area of our work. The ability to harness the large surface area-to-volume ratios and the unique surface sites of nanoparticles in <10 nm size range, especially in heterogeneous catalysis, constitutes a major driving force in fundamental research and practical applications of nanoparticle catalysts. It is this size range over which the metal particles undergo a transition from atomic to metallic properties. The understanding of factors controlling the morphological and surface reconstitution associated with such a size range is of fundamental importance to the ultimate exploration of nanostructured catalysts. We have been investigating the interfacial structures and properties of core-shell types of nanoparticles consisting of gold or alloy nanocrystal cores and organic monolayer shells that were prepared by twophase synthesis (13) and processing (14) protocols. Important attributes of such nanoparticles include controllable size monodispersity, processibility, and stability towards size- and composition-tunable catalysis (15-21). Some of these attributes were studied for understanding their electrocatalytic properties in the oxidation of methanol and reduction of oxygen, which are of fundamental interest to fuel cell technology.

Oct 1, 2003

To produce high quality castings, one must monitor the melt quality by evaluating such parameters as the grain refinement and silicon inoculation and modification during the production of the commercial casting. Thermal analysis is a tool one can use for both monitoring and providing input to the process control of the operation. The current technique of performing thermal analysis in commercial foundries is to pour a relatively small quantity of the molten aluminum alloy into a sampling cup and to then acquire the cooling curve. This approach is somewhat simplistic in that one has limited control of the cooling rate and hence the solidification rate of the sample. Moreover, this process requires a fair amount of user intervention and effort. In the past, studies have been conducted in an attempt to develop a system for conducting thermal analysis in-situ. In a study at McGill University, an alkali based heat pipe system was developed for conducting thermal analysis in-situ. While the concept was deemed as very desirable, the complexity of the equipment and procedure was a substantial negative component. In order to improve the technique of accomplishing real-time thermal analysis with an in-situ probe, a new method that is based on McGill heat pipe technology was developed. In the new system, a controllable and flexible water based heat pipe probe is used to solidify a small quantity of metal while residing in the melt. The solidified aluminum is remelted after completing the thermal analysis. This is a key feature of the probe. It resides permanently in the melt yet it is able to both solidify a sample of the melt and then to subsequently remelt it. Various solidification rates encountered in commercial castings are attainable by adjusting the heat extraction rate of the unit.

Jan 1, 2004

By John Lund

INTRODUCTION GOLD-BEARING placers of Alaska and the Yukon Territories are buried under a layer of permanently frozen alluvial overburden, or &apos;muck&apos;, which varies in depth from twenty to one hundred feet. The placers, and the decomposed bedrock layers upon which they are deposited, are also permanently frozen. During the summer, surface muck which is exposed to the sun will thaw, but only to a depth of a few feet. To reach a valuable deposit, the frozen overburden must be either penetrated with shafts, or stripped from the deposit entirely. In either case, before the placer can be mined, it must be thawed. At modern dredging operations, the frozen muck is stripped from the placer by powerful jets of water from hydraulic giants. The placer, and several feet of decomposed bed-rock, are then thawed by forcing water through narrow pipes which have been driven into the deposit. Other methods of thawing frozen placers were used extensively during the early years of the Klondike &apos;gold rush&apos;, but experimentation later proved that creek water at its natural summer temperature was a more effective and economical thawing medium than any other which had been used. EVOLUTION OF COLD WATER THAWING Early prospectors of the far north reached placers by digging shafts through the frozen muck. They then thawed the placer sand and gravel by building wood fires at the bottom of the shafts.

Jan 1, 1951

By R. Pressacco

"IntroductionAgrium’s history in fertilizer production and marketing goes back to 1931. Today, Agrium Inc. is a world leader in the production, distribution, and marketing of fertilizers and related products to the agricultural industry. Agrium is the largest North American producer of nitrogen fertilizers, a major producer of phosphate and potash fertilizers, and a world leader in fertilizer wholesale distribution and retail marketing. The mine at Kapuskasing is located some 40 km southwest of Kapuskasing, Ontario (Fig. 1). It has been developed to supply high-quality, low-cost phosphate rock to the company’s Redwater, Alberta facility, where it is an ingredient in ammonium phosphate fertilizer production. The Kapuskasing mine is the only phosphate mine in Canada and will rank as one of the highest-grade phosphate mines in the world (Clark and Duncan, 1999). Apatite is the principal ore mineral mined at the Kapuskasing Phosphate Operations.GeologyThe first record of exploration in the area was from a program executed by Continental Copper Mines in 1955 which evaluated the magnetic anomaly located in the Cargill and Cumming townships for its base metal potential. Intermittent exploration of the base metal potential of this magnetic anomaly continued in the following years, until the phosphate potential of the area was first examined in 1974 by International Minerals Corporation which recognized the presence of a layer of apatite sands overlying the carbonatite host rocks.The local geology consists of a core complex of multi-phased carbonatite rocks which are surrounded by a ring of pyroxenite, and have provided a U-Pb age date of 1907 Ma ± 4 (Sage, 1988). These two rock types are in turn situated within quartz diorite gneisses that form a large portion of the Kapuskasing Structural Zone (Fig. 2). The carbonatite host rock is sub-divided into two sub-types: sovite and rauhaugite. The sovite is a medium- to coarse-grained, white, banded rock in which calcite is the dominant carbonate species and it includes accessory minerals such as phlogopite, magnetite, clinohumite, apatite, olivine, pyrrhotite, and amphibole. Apatite can reach 15% abundance in this rock type (Sage, 1988). In sharp contrast to the sovite, the rauhaugite appears as a massive, fine-grained, dense, beige to tan-coloured rock in which dolomite is the dominant carbonate species. Phosphate values can range to 14% P2O5 in the rauhaugite."

Jan 1, 2001

By E. Goodwin

The mechanics of formation of wear-metal suspensions in lubricants is discussed, along with the relationship of the concentration of the metals and other particles to the wear of lubricated machinery parts. The importance of particle and suspension analysis of used lubricants in a preventative maintenance program is stressed, in particular with regard to mobile equipment in a mining operation.

Jan 1, 1978

By A. Warczok

Smelting slags contain payable metals in a dissolved form and as mechanically entrained matte or metallic inclusions in the size range from 2 to 1000 µm. Slag cleaning requires reduction of magnetite and metal oxides and sedimentation of inclusions. Slag cleaning in an electric furnace is carried out in batch or semi-continuous mode. The strong trend for continuous slag cleaning generates the basic question about the optimal geometry of the electric furnace. Results of combined CFD, potential distribution and heat transfer modeling allowed for the determination of the fluid flow pattern and the temperature distribution in a classical, circular electric furnace as well as in a rectangular furnace. For the rectangular furnace, various length/width ratios and position of electrodes have been simulated. Analysis of key phenomena pointed out the advantages of the rectangular electric furnace over the circular furnace, particularly for continuous slag cleaning. Phenomena that have been analyzed were mass transfer, the rate of slag reduction, coalescence and settling of inclusions, all on the basis of the calculated slag flow pattern and the temperature distribution.

Jan 1, 2007

By X. -G. Chen, J. Qin, K. Liu, D. Racine

"Understanding the thermo-mechanical fatigue (TMF) behavior of materials plays a significant role in the safety design of critical components used in aerospace and automotive industries, such as engine blocks and cylinder heads, which undergo the cyclic change of temperature and stress. However, the cyclic changes of temperature, stress and strain make it difficult using the traditional testing methods to accurately simulate the TMF process. In the present work, the Gleeble® 3800 system was successfully applied to develop a reliable procedure to measure the TMF behavior of aluminum alloys. The modified setup together with the new designed program allows the Gleeble system to precisely simulate the cyclic profiles of temperature and mechanical strain. The novel procedure includes the calibration and verification of the TMF setup to ensure the test validity with Young’s modulus measurement, multi-cycle measurement of the thermal strain and zero stress adjustment followed by online monitoring the TMF cycles. The results of the TMF testing of an AA6061 alloy under cyclic temperatures (60–300°C) and various strain amplitudes (0.2–0.6%) were demonstrated. Its TMF behavior was characterized by the typical hysteresis loops and cyclic stress-strain response.INTRODUCTION The thermo-mechanical fatigue (TMF) behaviour becomes increasing important to evaluate the elevated-temperature properties of materials used as the critical components in automotive and aerospace industries, such as the gas turbines (Hu, Shi & Yang, 2016; Moverare, 2007; Segersäll et al., 2015) and engine blocks (Grieb, Christ & Plege, 2010; Javidani & Larouche, 2014). During the cycles of start-up and shutdown of the engines, these components undergo a complex change of loading. Meanwhile, a dramatic temperature gradient exists on the components due to the cooling system. Therefore, the cyclic changes of load and temperature can give rise to the TMF and may limit the use life of such components (Hu, Shi & Yang, 2016; Javidani & Larouche, 2014; Moverare, 2007). Hence, performing the TMF tests to precisely simulate the cyclic changes of load and temperature to understand the TMF behaviours of materials is playing a significant role in the safety design of these components. For TMF tests, two principal types of cycles are generally employed, including the in-phase (IP) cycle where the load and temperature are at the same phase (i.e. maximum load at highest temperature) and out-of-phase (OP) cycle where the maximum load is applied at minimum temperature (Kliemt, 2012; Miller, 2014). The most significant damage mechanisms in engine components are reported to be OP TMF cycles (Javidani & Larouche, 2014; Kliemt, 2012)."

Jan 1, 2018

By J. Font

New approaches for the fire refining process of blister copper have been carried out at the Codelco Norte Smelter. These have been mainly focused on modification and improvement of the process configuration based in fluid-dynamic and metallurgical studies of the oxidation and impurity treatment stages. This paper presents the results of the laboratory simulations and industrial tests performed in the 250 t anode furnace, evaluating two different process configurations: ? Bottom Bath Agitation System in the vessel during the oxidation stage, ? Dual Flux Injection System during the impurity treatment stage. The results show the possibilities of effective removal of high content of sulfur from the melt during the oxidation stage by using the bottom bath agitation. The use of the dual injection system demonstrated the significant improvement in the removal efficiency of impurities. Cu2007

Jan 1, 2007

By James Ball

The paper describes a new type of pump and related apparatus specifically designed to dredge sea-floor minerals from very great depths. The principle of operation of the dredging system is explained, and the factors which determine the equipment size and the power required for varying mining rates and depths of water are discussed. An estimate of the capital and operating cost of a commercial-scale mining system is presented.

Jan 1, 1968

By Fabio Terzi

In this investigation some preliminary results are reported about the electrochemical oxidation of CO using goldbased encapsulated nanoparticles grafted on conducting substrate. The investigation has been planned in four steps: 1. production of Au(111) substrate and modification with self assembled monolayers; 2. synthesis and embedding of nanoparticles; 3. grafting of encapsulated nanoparticles on electrode substrates; 4. investigation of CO electroxidation on the modified electrode. The systems were characterized by means of various techniques (spectroscopic, microscopic, and electrochemical methods), obtaining information about SAM&apos;s structure and morphology, size and composition of nanoparticles and electrochemical behavior of modified electrodes.

Oct 1, 2003

By N. Erarslan, M. Ghamgosar

With the increased use of mechanized rock excavation, there have been developed internationally a number of methods to assess the abrasivity of rock materials. These methods range from determination of abrasive and hard mineral content using petrographic thin section analysis to weight loss or rate of wear flat development on specified test pieces. The Cerchar abrasivity index (CAI) test has been widely accepted for the assessment of rock abrasiveness and is determined as the abrasion of a steel pin after scratching over the freshly-broken or saw-cut surface of a rock. Two types of testing devices are in use today: (i) the original ‘Cerchar apparatus’, and (ii) the ‘West apparatus’, which was adopted herein. The CAI is calculated from the measured diameter of the resulting wear flat on the steel pin after 10mm scratching. This test has been considered to provide a reliable indication of rock abrasiveness for isotropic rocks. However, a great amount of rocks in natureis anisotropic. Phyllite is an anisotropic and foliated metamorphic rock and various types of phyllite specimens were tested in this research. Although phyllite is a type of rock primarily composed of quartz and the expected CAI value can be high, mechanical cutting of this rock should not be very problematic compared with igneous rocks have same CAI value. As phyllite is a foliated metamorphic rock, most of the specimens split into sheets through the quartz seam by the tip during scratching normal to the axis of quartz seams. Hence, viability assessment of Cerchar abrasivity test and F-Schimazek index values for the anisotropic rocks is investigated in this research.

Jan 1, 2015

By E. Peek, L. Becze, K. Reading

"Gallium oxide is an important semiconductor material used in optoelectronic devices (flat panel and solar cell) catalysts and sensors. One of the methods to produce ?-Ga2O3 is the so-called hydrothermal route. It is practiced by Neo Gallium Compounds and comprises of two steps: (1) the production of mainly gallium-oxy-hydroxide in a pressure vessel by reacting metallic gallium with water at 200-220 ºC and (2) the calcination of gallium-oxy-hydroxide at 700-750 ºC to convert it into ?-Ga2O3. This paper describes this pressure hydrometallurgy process supported with relevant thermodynamic data and presents the characteristics of the ?-Ga2O3 powder produced for commercial purposes. INTRODUCTIONGallium is a relatively new metal, having been predicted by D. Mendeleev in 1871, discovered by P.E. Lecoq de Boisbaudran in 1875, and first commercially produced in the USA in 1943. Gallium is not rare, being more abundant in the earth crust than antimony, bismuth, molybdenum, silver and tungsten. However, few gallium minerals exist in nature, and the dispersion of gallium within other minerals add to the complexity of its recovery. In practice, gallium is found in dispersed state primarily in bauxites and in some sphalerites, and, to a much smaller extent, in some coals. At present, a very large proportion of the primary gallium in the world is recovered as a by-product of aluminum plants, mostly Bayer plants, where gallium is extracted from a bleed of the Bayer liquor (Roskill, 2011). In 2011, world production of primary gallium was estimated at 200 metric tonnes. In addition, there is a significant contribution of recycling to the overall yearly availability of the metal.Gallium exhibits fairly remarkable properties: it is liquid above 29.76 ºC, can be supercooled, and with its high boiling point (2204 ºC), is the metal with the widest liquid range. Gallium is magnetic, and is an excellent conductor of both heat and electricity. Gallium also displays a marked anisotropic electrical conductivity (Roskill, 2011). All these properties render gallium almost irreplaceable in the semiconductors (GaAs, GaN, GaSb, GaP wafers) and the optoelectronics industry (flat panel, solar cell)."

Jan 1, 2012