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By A. Navarra, C. Arrancibia, R. Yañez, C. Acuña, F. Valenzuela

"Discrete event simulation (DES) is a suitable framework to evaluate and optimize the dynamics of sulphide smelters. In particular, iron-nickel-copper-cobalt sulphides undergo continual oxidation within a roasting or smelting operation, followed by batch oxidation within the converting operation, thus producing iron-free Bessemer matte (or blister copper, in the case of copper smelters); this semi-finished product undergoes further processing to produce nickel, copper and cobalt products, and to recover precious metals. The juncture between continuous smelting and batch converting is often an appropriate focus for the earliest phases of DES development, since it is typically a major bottleneck within nickel and copper smelters; later phases may include increasing levels of detail for auxiliary unit operations, as well as plant logistics. Moreover, DES can support matte-slag chemistry, including Gibbs free energy balances to determine the iron speciation within the slag. DES is therefore capable of linking the fundamentals of oxidation reactions to the intricacies of plant dynamics.INTRODUCTION Discrete event simulation (DES) is gaining acceptance within the extractive metallurgy community, as a technique that quantifies the system-wide performance of metallurgical plants under conditions of uncertainty (Wheeler & McGinty, 2015). In particular, over 90% of smelters that process nickel-copper-cobalt sulphides and copper sulphides exhibit similar semi-continuous dynamics (Crundwell et al., 2011b; Schlesinger et al., 2011b), in which the converting aisle produces batches of material that are sent for further processing (Figure 1). Thus the tools and practices that are developed for a specific sulphide smelter are often relevant to numerous other smelters.The juncture between continuous smelting and batch converting has long been a focus for discrete event simulation (Welgama et al., 1996). Nonetheless, the broad acceptance of DES in nonferrous smelters has been hindered by interdisciplinary barriers that divide industrial and metallurgical engineers (Navarra et al., 2016; Noorossana et al., 2012); this divide has been less severe in steel plants (Hollocks, 2006). In recent years, DES has been used in copper smelters to analyze crane-and-ladle motions (Coursol et al., 2009a), reverts production and consumption (Noorossana et al., 2012), and innovative control systems (Herrera et al., 2016); additionally, DES models have accounted for shutdowns and random breakdowns to provide realistic assessments of copper smelter capacities, thus guiding equipment upgrades (Campbell et al., 2013; Coursol et al., 2009a). All of these studies feature a Peirce-Smith converting aisle similar to Figure 1 that, under normal operations, constrain the smelter throughput, and are thus a bottleneck (Campbell et al., 2013; Navarra et al., 2016)."

Jan 1, 2017

By G. Goodall, M. Muinonen, R. Pandher, R. Jabbar, S. J. Muinonen

"The implementation of a new and highly efficient converting practice at the Glencore Sudbury Integrated Nickel Operations Smelter has opened the possibility to further capacity increases by using larger ladles. To quantify the impact of increasing ladle sizes from 200 to 300 ft3, XPS constructed a detailed discrete event simulation using the commercial software package Rockwell Arena®. The challenges associated with implementing a model on an intricate and tightly scheduled process, and the solutions needed to derive meaningful results will be presented. The aisle capacity is predicted to increase by approximately 17 %, with a reduction in furnace tapping demand of 8 %. Arena modeling capabilities and the key factors contributing to the overall capacity increase at the Sudbury INO Smelter will be reviewed and presented.INTRODUCTION The Glencore Sudbury Integrated Nickel Operations (INO) comprises two Ni-Cu-PGM mines, Strathcona Mill, and the Sudbury Smelter. The Smelter has operated continuously since 1929 using different processes to produce nickel-copper Bessemer matte. Feeds to the Sudbury INO Smelter are a blend of concentrate from Strathcona Mill, Raglan concentrate produced at the mine-mill complex in Raglan, Quebec, as well as third party concentrate feeds shipped to Sudbury from around the world. In 2016, the Sudbury INO Smelter produced 75,900 tonnes of nickel and 20,000 tonnes of copper in Bessemer matte. The product matte is shipped to Glencore’s Nikkelverk refinery in Kristiansand, Norway where it is refined to produce nickel and copper cathode. A schematic of the Sudbury INO Smelter’s flowsheet is shown in Figure 1."

Jan 1, 2017

By N. Tassé

Les substrats organiques sont à la base des biofiltres utilisant la réduction des sulfates pour générer de l&apos;alcalinité et diminuer la concentration des métaux dans des effluents contaminés. Afin de tester l&apos;efficacité de résidus forestiers utilisés dans de tels contextes, cinq types d&apos;écorce de nature et d&apos;âge variables ont été placés dans des contenants hermétiques et mis en présence d&apos;une solution synthétique de drainage minier acide. Le pH, l&apos;alcalinité et les concentrations de Fe2+ et SO4 2- ont été mesurés à intervalles réguliers pendant 70 jours. L&apos;importance d&apos;un éventuel neutralisant minéral et du type de souches de bactéries sulfato-réductrices pour l&apos;initiation et l&apos;évolution des réactions d&apos;oxydo-réduction ont été évalués en utilisant de la dolomite ainsi que des inocula de sédiments portuaires réducteurs et de boues d&apos;usine d&apos;épuration. Une augmentation de pH et des diminutions de Fe2+ et SO4 2- ont été notées dans tous les réacteurs. En l&apos;absence de dolomite, le pH augmentait de 1.6 à 5-6, Fe2+ diminuait de 400 à moins de 5-100 mg/L, et SO4 2- diminuait de 2500 à 750-1250 mg/L. Les échantillons inoculés avec des sédiments s&apos;avéraient légèrement plus performants que ceux avec boues. En présence de dolomite, le pH atteignait 6.5-7.0, et Fe2+ et SO4 2- tombaient à <5 et 20-40 mg/L, respectivement. Le degré de réactivité des résidus forestiers n&apos;était pas une simple fonction inverse de leur âge. Les échantillons ayant le mieux réagi, bien que parmi les plus vieux testés (années 1980), étaient ceux contenant une proportion significative d&apos;écorces de feuillus et peu de bran de scie. Les échantillons avec des proportions élevées d&apos;écorce de conifères ou de bran de scie étaient associés à des taux de réduction moindre. Nonobstant l&apos;amélioration rapide des conditions obtenue avec la dolomite, grâce à une neutralisation initiale plus prompte, il s&apos;avère que le type de résidus forestiers éventuellement utilisé dans une barrière réactive est de première importance pour l&apos;efficacité des mécanismes de réduction. Un système basé sur l&apos;utilisation de résidus forestiers devrait utiliser des écorces (plutôt que du bois) provenant de feuillus (plutôt que de conifères).

Nov 1, 2002

By The Staff

Introduction It is the purpose of this paper to discuss a number of the metallurgical improvements in the technology of copper-nickel ore treatment which have been introduced during recent years in the plants of ?the International Nickel Company of Canada, Limited. In common with other ore treatment processes, the procedure for extracting nickel and copper is changing almost continuous! y. These changes are necessitated by reason of changes in ore grades and characteristics, rising material and labour charges, and the constant drive to maximize metal recovery and to minimize production costs. It is not possible to present a comprehensive list of all the changes made, and only a selected number of the improvements in the milling, smelting, and refining operations are covered. It should be clearly understood that some phases of the procedures described have been pioneered by others in kindred fields and due acknowledgment is given to their foresight and efforts. Articles have been published over the years describing the operations of the International Nickel Company plants and the reader is referred to the Engineering and Mining Journal, Vol. 130, No. 9, November 10th, 1930, and to the Canadian Mining Journal, Vol. 58, No. 11, November, 1937, and Vol. 67, No. 5, May, 1946. Other references are the Transactions of this Institute, 1932, 1938, and 1946; Metals Technology, American Institute of Mining and Metallurgical Engineers, February, 1938, and Canadian Chemistry and Process Industries, April, 1940.

Jan 1, 1948

By J. Robison, H. Pieterse, C. C. Smith, M. Luque, S. Chipman

Phase change during pressure let down releases significant amounts of energy that must be controlled to avoid undo wear and tear on equipment. Hydrometallurgical slurries require flow control equipment (valves and tanks) made of expensive materials to withstand the abrasive, and often corrosive nature of the slurry. Presented is a model of the nozzle of a let-down choke which is designed to control the flow pattern that exits the choke (valve) as it enters the receiving tank. This model can be used to design chokes which allow for the dissipation of the energy released during pressure let down by spreading the stream over a significant portion of the slurry pool in the receiving tank to minimize wear on equipment near the nozzle exit and the bottom of the slurry tank. An example uses the model to choose the nozzle expansion (area) ratio to select the outlet slurry velocity and slurry expansion angle.

Jan 1, 2004

By S. Hobo, M. Yagisawa, T. Uchida, C. Tokoro, T. Kato

In this study, quantitative modeling was carried out for the treatment of simulated waste water containing As(V), Zn(II) and Hg(II) as toxic elements, and Fe(III), Na(I) and sulfate as coaxing ions. The objective was to predict the pH and residual concentrations of all the elements in solution after the neutralization/co-precipitation treatment. To accomplish this, the removal mechanism for As(V) and Hg(II) by ferrihydrite precipitation was first investigated for simulated waste water containing only As(V) or Hg(II). From the experimental results, it was confirmed that the removal mechanism involves not only surface complexation but also surface precipitation. However, surface complexation is the main mechanism for As(V) and Hg(II) removal to meet the target levels regulated in Japan. Next, the surface complexation model was constructed for the removal of As(V) and Hg(II) by ferrihydrite. The specific surface area and site density were determined from reference values proposed by Dzombak and Morel (1990). By comparing the experimental and calculated results, it was confirmed that our constructed model could successfully represent the experimental results. Furthermore, the surface complexation model was coupled with chemical equilibrium calculations and applied to the neutralization of simulated waste water containing As(V), Hg(II), Zn(II), Na(I), Fe(III) and sulfate. The constructed model could successfully represent the pH edge for As(V), Hg(II), Zn(II), Fe(III) and SO42- removal. In addition, the constructed model could represent the ion balance. Thus, our constructed model is useful to estimate the amount of neutralizer that is needed to achieve a target pH.

Jan 1, 2016

By D. C. McDonald

"IntroductionTHE GIANT YELLOWKNIFE property is on the west side of Yellowknife bay, Great Slave lake, N.W.T., some 600 air miles north of Edmonton. This paper deals with the underground development and mining of the complex system of orebodies which have produced, in the first fifty-six months of operation (May, 1948, to December, 1952), 652,464 tons of ore with an average grade of 0.80 ounces of •gold per ton (1).The mine has been developed from three vertical shafts designated A, B, and C. Figure l shows the positions of these openings with respect to the known ore-bearing zones and the surface plant.A shaft was sunk to a depth of 522 feet in 1945-46, primarily as a prospect shaft for investigation and development of the East Zone orebody. Drifting was carried out on the 200-and 325-foot levels. Before this development had been completed it was clear that the funds immediately available made it imperative to get revenue from production as soon as possible. By the beginning of 1946, the remarkably high-grade character of the ore in the present B Shaft area had been established by surface drilling, and the decision was made to obtain initial production from this source. Since known orebodies at shallow horizons were to be developed quickly, the choice of a suitable rock outcrop for the shaft was something of a problem."

Jan 1, 1953

By C. A. Petch

Abstract - The High Lake polymetallic deposit is located in the northern Slave province, 40 km south of Coronation Gulf, Nunavut. The main zone, the AB zone, hosts an estimated resource of 3.56 Mt grading 5.0% copper, 1.1% zinc, 0.06% lead, 1.7 g/t gold, and 18.2 g/t silver. Archean felsic metavolcanic and metavolcaniclastic rocks are the dominant rock type and are associated with lesser mafic metavolcanic and carbonate-rich metasedimentary rocks. The sequence strikes north-northeast, dips steeply to the west, and is truncated to the west by a large granodioritic intrusion. The mineralization at the AB zone is comprised of massive and stringer chalcopyrite-sphalerite-pyrrhotitepyrite± galena. At the core of the mineralized zone, intensely chlorite-altered rocks are locally metamorphosed to form distinctive zones of anthophyllite-magnetite-cordierite-altered rock. Peripheral to the mineralized core, alteration consists of sericitization, silicification, and weaker chloritization. Primary morphology and facing direction of the zone are difficult to interpret in part due to poor primary metal zonation of the deposit. However, the irregular shape of the mineralized zone and the erratic zones of zinc enrichment at the fringes are consistent with the interpretation that the zone was formed by the replacement of a porous volcaniclastic pile.

Jan 1, 2004

By E. Brzychczy

Artificial intelligence techniques are ever more frequently implemented in the modern world. One of their numerous uses is supporting enterprise management. Intelligent techniques and intelligent information technology (IT) systems can be implemented in mining-related issues as well. The author of this article concentrates on supporting the process of planning mining operations by intelligent systems and techniques. The author also underlines the importance of knowledge accumulation in a mining enterprise (especially tacit knowledge) as well as its efficient storing and using. Additionally, the author provides a short description of characteristics of intelligent IT systems and indicates their capabilities in planning mining operations. She presents two solutions, namely: an advisory system which supports the process of planning preliminary works and exploitation works in hard coal mines, and a method of modeling and optimizing mining operations. Finally, the author indicates a few possible future development trends of intelligent systems - the intelligent systems of decision support.

Aug 1, 2013

By S. Heusermann, S. Fahland, J. Behlau, A. Schäfers, J. Hammer

In the course of the deep subsurface use, the Federal Institute for Geosciences and Natural Resources has been carrying out extensive geological and geomechanical research and practical project work on domal salt structures, to prove their suitability e.g. for the disposal of radioactive wastes. Recent work on disposal sites has been taking into account the 3-D geological and geomechanical modelling of the underground structures. The geological models are generated using the special-construction openGEOTM code to improve the visualisation and interpretation of the geological data basis, e.g. borehole, mine, and geophysical data. For the geomechanical analysis of underground structures the JIFE finite-element tool has being developed to analyze large 3-D structures and to consider coupled THMC processes. The results of finite-element calculations, i.e. stresses, strains, displacements, and dilatant zones, are basic values for the evaluation of the stability of the structures and the long-term integrity of the geological barrier. As an example, the results of geological and geomechanical investigations of the Morsleben repository are presented including three-dimensional modelling of the entire geological structure of the central part of the mine as well as three-dimensional geomechanical model calculations to provide the necessary results for a long-term safety prediction.

Jan 1, 2015

By X. Zhou

"Hydrogen induced failure and degradation in structural metals, namely hydrogen embrittlement, has been a long-standing industrial problem for more than one century and remains unsolved. Despite the proposal of numerous models, no consensus has been reached, and considerable discrepancies in experimental observations and theoretical calculations exist. One aspect that is central to the understanding of hydrogen embrittlement is the interaction between hydrogen and grain boundaries. In this study, we investigated the influence of several solute elements (i.e., Cr, Mo and Nb) on hydrogen segregation at the representative 9 grain boundary using first-principles calculations. Our results showed that the presence of Mo and Nb can reduce the tendency of hydrogen segregation at grain boundaries, while meanwhile enhance the grain boundary strength. This indicates that Mo and Nb are salutary elements that can be used to increase the material’s resistance to hydrogen embrittlement, providing new insights in designing hydrogen embrittlement resistant Ni alloys. INTRODUCTION Hydrogen embrittlement (HE), a phenomenon of hydrogen triggering premature failures in structural metals, has been a headache for industries ever since its first discovery one century ago (Johnson, 1874; Zhou, Marchand, McDowell, Zhu, & Song, 2016; Zhou, Ouyang, Curtin, & Song, 2016). It is well accepted that the segregation of hydrogen at microstructures such as grain boundaries (GBs) plays a key role in determining the occurrence and severity of HE. GBs are two-dimensional defects where significant local lattice distortion exist, which leads to large free volume and thus locations for hydrogen trapping and segregation. Numerous works have clarified GBs as the energetically preferable places for hydrogen segregation. For instance, Geng et al. demonstrated the preferential segregation of hydrogen at the S5(120) GB in several metals, and suggested a decohesion-type of HE in light of Rice-Wang thermodynamic theory (Geng, Freeman, & Olson, 2001). Birnbaum et al. illustrated that complete intergranular crack of Ni GBs can be induced by hydrogen segregation when the hydrogen concentration is sufficiently high, evidencing the significant role of hydrogen accumulation on GB weakening (Lassila & Birnbaum, 1987). Yamaguchi et al. demonstrated strong segregation hydrogen also occurs at S3 GBs in alpha-iron, showing that local hydrogen clustering (i.e., multiple hydrogen atoms, up to six, per unit cell) can be trapped at the S3 GB (Yamaguchi, Kameda, Ebihara, Itakura, & Kaburaki, 2012)."

Jan 1, 2017

By J. G. Debanne

MOST company-employed petroleum engineers have in their accounting departments punch-card computers that can perform engineering calculations thirty to three hundred times faster than desk calculators, or they can rent such machines from Computing Service centres. These machines not only eliminate the drudgery of desk calculation but also the risks of human errors. The I.B.M. t 604 punch-card computer of Texaco&apos;s accounting department in Calgary has been used for oil and gas property evaluations, curve fitting by least squares, statistical core analysis studies, unsteady-state water in-flux studies, phase equilibrium performance prediction of oil reservoirs, gravity segregation calculations, etc.

Jan 1, 1958

By Y. Kashiwaya, J. Yagi, P. R. Austin

The problems of global environment and resources have become important issues in recent years, and the iron and steelmaking industry is requested to decrease energy consumption and carbon dioxide emission. The improvement of efficiency of ironmaking system is one of the countermeasures for these problems because more than a half of total energy input to the integrated steelwork is input to the ironmaking system. Various approaches to improve the blast furnace process have been made. The authors examined their performances through mathematical simulations of blast furnace operation, and confirmed the improvement of blast furnace efficiency under some operating conditions. The ironmaking system consists of various processes, and the materials and the energy are transported among these processes. Thus it is necessary to evaluate the efficiency of the novel operation of blast furnace based on the ironmaking system. In this study, the balances of material and energy on ironmaking system that consists of blast furnace, coke oven, sintering and hot stove processes were analyzed. The operation status of each process in the system was adjusted according to the results of the operation simulation of the blast furnace under novel operating conditions. The analysis clarified the effect of the blast furnace operation on the energy balance and CO2 emission of the ironmaking system.

Jan 1, 2015

By L. H. Van Loon, E. G. Crayston, A. F. Heather

"IntroductionTHE PROPERTY of Madsen Red Lake Gold Mines. Limited. comprises fifty-eight claims located between Russet and Faulkenham lakes in Baird and Heyson townships of the Patricia portion of the District of Kenora. The mine is seven miles •by road from the hamlet of Red Lake. This latter centre is .connected to the Trans-Canada Highway at Vermillion Bay, Ontario, by provincial highway No. 105 which has a total length of one hundred and thirteen miles.The Madsen property went into production on August 11th, 1938, with a milling plant rated at 300 tons per twenty-four hours. Changes made in the crushing plant during October, 1938, allowed a •finer feed to be delivered to the mill and increased the milling •capacity to 400 tons per twenty-four hours. During 1948, steps were taken to add an additional 400-ton capacity unit to the milling plant. This latter work was completed by May, 1949, giving the present total milling .capacity of 800 tons per twenty-four hours.It was realized in the early 1940's that, eventually, considerable material suitable for backfilling in the mine would be required. As there were no large deposits of gravel or sand anywhere near the mine, officials of the Company considered it advisable to investigate the feasibility of using mill tailings for mine •backfill. Since Madsen mill tailings contain approximately 80 per •cent of minus-200-mesh material, it was not considered practical to use them for underground backfill without first removing the finer material. as the slimes present in a product of this fineness would without doubt preclude any drainage whatsoever. Table I gives a sizing analysis of Madsen mill tailings and Table II a quantitative chemical analysis of the ore."

Jan 1, 1954

By Jiuhua Xu, Shuiku Jia, Weiren Sun

"The Jinqingding gold deposit, situated in the east Jiaodong Peninsula of Shandong province, is typical of the pyrite-quartz vein gold deposits in the Muping-Rushan gold belt of China. The gold deposit is controlled by a great NNE fracture zone and is composed of several lenticular orebodies within the fracture rone occurring in the Kunyushan granite massif. The Kunyushan granite massif was formed by the replacement of the Archean Jiaodong group.The main minerals associated with gold are pyrite, chalcopyrite, galena and sphalerite; the gangue minerals are dominated by quartz, sericite, microcline and calcite. The mineralizing event can be divided into four stages: (1) pyrite-quartz; (2) quartz-pyrite; (3) siderite-polymetallic sulfides; and (4) calcite-quartz. Gold occurs mainly as native gold and electrurn in stage I and stage II. There are some evident differences between pyrite from major stages of gold mineralization and that from minor stages; these include differences in crystal forms, size and composition of fluid inclusions.Wallrock alterations consist of sericitization, silicification, pyritization and potash-feldspar alteration. Five alteration zones can be distinguished from unaltered granite (zone 0) to vein lodes (zone IV). Au and Ag increase rapidly from zone 0 to rone IV, Cu increases continuously, while Pb and Zn increase slowly. R-type geological factor analysis indicates that the Au, Ag, Cu, Pb and Zn bear a close relationship to wallrock alteration."

Jan 1, 1994

By Kamran Esmaieli

Open Pit Mining Through Underground Voids: Challenges Main Challenges/Hazards: Unexpected collapse of the pit floor and/or pit walls; The loss of equipment and/or people into underground voids; Loss of explosives from blast holes that broken through into the underground voids. How to address these challenges? An important step that must be integrated into mine planning and design is the accurate detection and delineation of underground voids. (i.e. probe drilling, Geophysical techniques, laser scanning,?); Leaving a pillar of adequate thickness between the working bench and the underground voids; Backfilling the underground voids from surface using vertical or inclined raises; Monitoring the working locations (pit floor and pit slopes) to detect movements.

May 1, 2013

By David Ulrich Furrer

Materials and manufacturing processing technologies have played an important role in the development and capabilities of nearly all manmade products. Market drivers for fuel efficient, low cost, environmentally friendly, more capable transportation has given rise to significant materials challenges and subsequent developments. The rate of improvement and implementation of new commercial products can be limited by the rate of new materials and process technology development and qualification. As many materials are being designed for unique requirements and even location-specific unique properties, the implementation of tools and methods to enable rapid characterization and validation of material definitions and design systems must also be accelerated. A review of new integrated material, manufacturing process and component designs, engineering processes and emerging tools and methods will be discussed. The linkage of computational materials science and engineering into component design will also be discussed along with the challenges and opportunities for further growth and application of integrated computational materials engineering (ICME).

Jan 1, 2015

By Sandeep Singh Sandhu, Karanvir Singh Ghuman, Manjit Singh

"Cobalt based super alloy stellite 6 was weld cladded on AISI 304 L stainless steel using SMAW process in order to improve the wear resistance for tyre crusher blades. Microstructure characterization and micro hardness testing was performed on stellite 6 cladding. The suitable parameters viz. 80 Amp current with arc weaving technique was selected by performing bead on plate experiment were further used for depositing multipass multilayer cladding to achieve full filler chemistry at the top surface. Further GTAW process was used for re-melting the top surface of the cladding. Comparative evaluation of the claddings showed that TIG re-melting resulted in increased microhardness and wear resistance in comparison to as cladded specimens even with lesser deposition of material. It was observed that TIG re-melting improved the hardness from 603 HV0.5 kg to 712 HV0.5 kg. Micro structures of stellite 6 contained cobalt solid solution matrix along with inter dendrite chromium carbides which resulted in the increased micro hardness values. Pin on disc abrasion tests were carried out at room temperature and the worn out surfaces were characterized using SEM and EDS.INTRODUCTIONThe crusher blades are used in many industries for crushing various types of material and its wider applications in tyre rubber crushing mills, metal-powder crushers industries etc. Most of the crusher blades are damaged by the wear and impact loading conditions. It is because of metal to metal abrasion and the temperature also plays a vital role in blunting the cutting edges of these blades. The wear is the major cause which leads to loss of material and thus the productivity that can never be recovered (Kotechi et al., 1992). The wear can be reduced by coating of various super alloys which could reduce the behavior of metal degradation even in aggressive environments. Cladding of cheaper low alloyed material with expensive superalloys to enhance the performance of components at low cost has been investigated by many scholars (Deng et al., 2010, Kennametal, 2007, Lolla et al., 2014, Singhet al., 2014, J.N et al., 2003, Ramkumar et al., 2012). Many researchers have reported that cladding is an application of build-up deposits of specialized alloys to resist abrasion, high temperature corrosion and impact loadings. Cladding is used for providing required mechanical strength properties as well as inhibition of oxidation and other corrosive degradation. Coatings are used to protect the heat affected areas like tubes of fluidized bed combustor etc. (Kirchbner et al., 2008, Wang et al., 1994, Hocking et al., 1993, Ananthapadmanabhan et al., 1991, Staia et al., 2001). Coating techniques are widely used for the protection of turbine engine and boiler tubes against high temperature corrosion attack, power generation equipment, chemical process equipment, aircraft engines, pulp and paper processing equipment, bridges, rollers and concrete reinforcements, orthopedics and dental, land-based and marine turbines, ships. Coatings of stellite 6 are widely used in steam turbine blades and boiler tubes for power generation because of an excellent combination of impact, wear and other properties. It can maintain its properties even at high temperature and in harsh environments (Kobayashiet al., 1999, Alam et al., 2009, Munehru et al., 2009). The loading and unloading conditions experienced by the material may induce the surface cracks which lead to its breakage and leaving large pits in the surface (Meng et al., 1995). Many researchers have reported that the properties of cladded layers can be increased by various techniques such as controlling the current variations, dilution, heat input, laser and other re-melting processes, addition of special alloying elements, speed of weldingetc(C.M Anaet al., 2002, Kumaret al., 1999, Luo et al., 2012, et al., Madadi et al., 2011, Shin et al., 2003, Kuzucu et al., 1997, Sudha et al., 2008, Sawant et al., 2017, Houdkova et al., 2016, Ciubo"

Jan 1, 2017

By Y. Serres

In the past, conventional reflection seismic techniques were not very successful when applied to typical mining exploration: they lacked resolution in the shallow range or were not cost effective. By combining a light earth tamper source, special geophones and field procedures, a stacking process of the returning seismic events using a microprocessor system, and a sophisticated sequence of adapted digital data processing, Mini-Sosie achieves high resolution in the 100-ft to 4000-ft range. Additional advantages result from the very quiet nature of the source and flexibility of the system. Although Mini-Sosie might be used in the refraction mode, or for well velocity logging, it has found its main applications with the reflection technique.

Jan 1, 1978

By Daan Maijer, Wade Marquardt, Robert MacKay, Steven Cockcroft, Farzaneh Farhang Mehr

"To comply with the new Corporate Average Fuel Economy (CAFE) standards, the automotive industry is aiming to reduce weight and increase the power and efficiency of small displacement engines through the application of forced induction technologies. As an example, there are now several 2.0 litre turbocharged engines in production, producing in excess of 240 hp. To meet the need for improved fatigue properties in the engine blocks used in these high-output engines, a new water-cooled chill technology is under exploration at UBC in partnership with General Motors and Nemak. A series of experimental techniques were used to assess the capability of the new chill to extract heat from an A319 casting in the vicinity of the main bearing bulk head. The results show that this method has the potential to achieve a reduction in secondary dendrite arm spacing thus meeting the new microstructural specifications for these engines.INTRODUCTION The automotive industry is working to meet the stricter efficiency requirements laid out within the CAFE (Corporate Average Fuel Economy) regulations (Bastani, 2012; Cole, 1995; Mackay, 2011; Miller, 2000), while at the same time not sacrificing performance. One approach is to increase the use of lightweight materials, which leads to a decrease in the overall vehicle weight and fuel consumption (Cole, 1995; Mackay, 2011; Miller, 2000). Other approaches include smaller displacement engines and gas-electric hybrid drivetrains. However, one trend that is becoming clear, is a greater emphasis on force induction gasoline engines. This allows for weight reduction to be achieved with smaller displacement engines without sacrificing performance. One consequence of this approach is that the engine block materials are subject to higher in-service thermal and mechanical cyclic loads (Cole, 1995; Miller, 2011; Heysler, 2001) The fatigue properties of an alloy are strongly affected by a number of the, as-cast, microstructure features including, Secondary Dendrite Arm Spacing (SDAS), porosity and eutectic lamella spacing (including intermetallic ß-Al5FeSi platelets) (Mackay, 2010a; Mackay, 2010b; Viet-Duc, 2015; Casellas, 2005). It is generally accepted they can act as fatigue initiation sites and that a reduction in their size will result in an improvement in fatigue performance. For a given alloy chemistry, one of the key parameters affecting the length scale of all three is cooling rate (Mackay, 2000)."

Jan 1, 2017