Search Documents

By S. H. Schulz

100 YEARS AGO, on the first of August, 1877, the mining engineer Friedrich Koepe was granted the patent rights for a hoist driving ropes on the principle of friction. It was named after him: the Koepe hoist. On the occasion of this centenary, the main features of the Kcepe principle are described.

Jan 1, 1977

By G. V. Poropat

Roughness of a discontinuity may be an important factor influencing shear strength of the discontinuity. Traditionally, determining the roughness of a discontinuity surface and providing a numerical measure of the roughness has required considerable effort or specialised equipment. The development of new 3D imaging tools that are easy to use has provided effective fast and accurate means of creating 3D surface models from which roughness measurements can be readily obtained. These new techniques are versatile enabling a user to measure roughness along any desired profile and at any resolution up to the limit of the spatial subtense of a measurement on the discontinuity surface. This paper primarily reviews extensions to the use of 3D imaging that enable the measurement of roughness. Additionally we provide some examples of the measurements and examine some of the issues associated with extracting measures from the spatial data that will support estimation of shear strength.

May 1, 2009

By Eldridge Haynes

IF you ask the average American to define 'total war' he is apt to fumble for an answer. But in Britain everyone knows the answer, because Britain has mobilized its total labour force, including women. If we were to match, proportionately to our population, Britain's mobilization of labour, we should have 60,000,000 people working full time in the armed services, civilian defence, and war industries. Actually we have fewer than 35,000,000 so employed. In Britain two out of every three persons between the ages of fourteen and sixty-five are so engaged. For the first time in the history of any democracy Britain conscripts women for service in the army, navy, and air force. Two hundred thousand British women have been conscripted for the army, known as ATS, meaning Auxiliary Territorial Service. There are more women in the air force than the total personnel of the RAF at the outbreak of the war and almost all of the land base jobs of the British navy are now handled by women. In addition to cooking and office work, Britain's women soldiers and sailors are driving trucks and motorcycles, repairing motor vehicles, packing and repacking parachutes, installing, inspecting, and maintaining gun equipment and ammunition of combat planes after each raid, raising and lowering barrage balloons, forecasting weather, manning harbour craft, sending and receiving radio messages. A normal ack-ack unit is composed of 229 women and 189 men. The women man the gun height finders and predictors, give bearings, and signal to fire.

Jan 1, 1942

By S. Torizuka, I. Mizushima. Kawasakitohri, A. Ohmori, K. Nagai

Strain (work)-hardening in tensile tests were examined for low carbon steels with various ferrite grain sizes ranged from 0.4µm to 16µm. The steels had microstructures composed of ferrite grains and dispersed cementite particles. They were fabricated through warm caliber rolling with an accumulative area reduction of 93%. Strain-hardening rate at a given strain increased with an increase in volume fraction of cementite particles. The balance of yield strength and uniform elongation for ultrafine-grained structures could be improved by the dispersion of cementite particles. Effects of the cementite dispersion and the ferrite grain size on the strain-hardening rate can be roughly explained by the work-hardening model with GN-dislocation density. Strain-hardening design using dispersed cementites was proved to be effective in controlling ductility of the ultrafine-grained steels.

Jan 1, 2004

By Y. Kusuda

Since 1981, the Annaka refinery has recovered zinc from zinc leach residues by the Waelz Process. The important considerations of this process are the prevention of the growth of coating accretions in the Waelz kiln and the improvement of the zinc volatilization rate. In this paper, simulation predictions and the results of the industrial operation regarding the prevention of coating accretions in the Waelz kiln and the improvement of the zinc volatilization rate at the Annaka refinery are reported and compared.

Jan 1, 2006

By K. B. Han, S. Winkler, M. J. Benoit, M. J. Worswick

"Automotive heat exchangers are fabricated by forming multi-layered aluminum (Al) alloy brazing sheets into the desired geometry and subsequently passing the assembly through a furnace for brazing. As manufacturers seek to use thinner gauge and higher strength sheet to reduce vehicle weight, forming of the Al alloy sheets has become a challenge. Warm forming has previously proven to allay these forming concerns, but no consideration was given to the effect of increasing the forming temperature on brazing. Recently, it was shown that annealed sheet was more susceptible to the detrimental phenomenon of liquid film migration (LFM) during brazing if formed above 150°C, while work hardened sheets showed no increased susceptibility to LFM with increasing forming temperature, up to 250°C. In the current study, the brazing performance of simulated battery cooling plates was investigated. The plates were fabricated both from fully annealed and work hardened sheets. Brazing was assessed by microstructural evolution during a brazing cycle. The post-brazed microstructure varied with strain and forming temperature in plates made from annealed sheets, while no variation in microstructure with location or forming temperature was observed in plates formed from work hardened sheets.INTRODUCTION Since the 1970’s, one common method of fabricating automotive heat exchangers has been by forming multi-layered aluminum (Al) alloy sheets, and subsequently brazing the formed components together in a controlled atmosphere furnace. The Al alloy sheets used are comprised of at least two Al alloys roll bonded together, but can consist of additional layers, depending on the application; at minimum, the sheets are comprised of a core and clad layer. The core layer, often an AA3xxx alloy, remains solid throughout processing and provides strength to the assembly. The clad layer is always one of the AA4xxx series alloys which, due to their high silicon (Si) content, have a melting temperature range well below that of the core alloy. When the sheet is passed through the brazing furnace, the clad alloy melts to provide the brazed joint filler metal throughout the assembly, while the core alloy remains solid. In order to achieve cost and weight savings, heat exchanger fabricators have used Al alloy sheets with reduced thickness. However, deformation and brazing of these increasingly thin components remains a concern (Zhao & Woods, 2013). Furthermore, springback has been observed after forming sheets of higher initial strength (i.e. work hardened conditions), leading to flatness issues of formed components. Consequently, the ability to form high quality brazed joints is difficult in components formed from higher strength brazing sheets."

Jan 1, 2018

By J. Sadaki, G. Dodbiba, S. Murakami, T. Fujita, S. Matsuo, H. Ono, K. Okaya

Printed circuit boards (PCBs) from discarded personal computer (PC) and household appliances were crushed by mechanical crushing or water explosion to remove mounted parts. More parts were stripped from PCB for PC composed of epoxy resin than from PCB for household appliance composed of phenol resin. In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 1073K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment. On the other hand, tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins by heat treatment at 723 to 773K in air atmosphere and screening of 0.5mm. Silica was removed and 70% of tantalum grade was obtained after more than 823K heating and separation.

Jan 1, 2011

By T. G. Joseph, R. K. Soni, M. Curley

"Rapid dampening suspension is a proposed suspension design for ultra-class haulers that is intended to avoid metal-to-metal contact inside a strut and under shock loading, thus improving ride quality and ameliorating fatigue loading issues on a hauler structure. Laboratory testing has shown the ability of the proposed design to reduce the opportunity for bottoming out, that is, metal-to-metal contact between the colliding ends of oleo-pneumatic, two-piece suspension struts during the compression cycle. This paper predicts the performance of a full-size rapid dampening suspension strut by applying scaling rules to test the proposed design based on a set of field data from a Caterpillar 797B ultra-class haul truck operating in the oil sands region of the province of Alberta, Canada. The predicted performance of the suspension strut is compared to that of the original equipment manufacturer model, which was monitored on board the truck during field data collection. ¦ KEYWORDS Haul truck, Original equipment manufacturer (OEM), Rapid dampening, Strut, Suspension RÉSUMÉ La suspension à amortissement rapide est une conception de suspension proposée pour des camions de transport de catégorie ultra-class (des engins dont la charge utile dépasse les 320 tonnes métriques), visant à empêcher un contact métal sur métal à l’intérieur d’une jambe de suspension et dans des conditions de choc au chargement. Elle améliore la qualité du roulement et les problèmes de charge de fatigue sur la structure d’un camion de transport. Les essais en laboratoire ont confirmé que la concep¬tion proposée évitera au cylindre interne de heurter le cylindre externe, autrement dit empêchera le contact métal sur métal des jambes de suspension oléopneumatique en deux parties pendant le cycle de compres¬sion. Cet article prévoit la performance d’une jambe de suspension à amortissement rapide à taille réelle en appliquant les lois d’échelle afin de mettre à l’essai la conception proposée, sur la base d’une série de données de terrain relatives à un camion de transport 797B de catégorie ultra-class de Caterpillar (aujourd’hui remplacé par le nouveau modèle 797F) utilisé dans la région des sables bitumineux de la pro¬vince de l’Alberta, Canada. On compare la performance prévue de la jambe de suspension à celle du modèle du fabricant d’équipement d’origine (FEO), qui a été contrôlée à bord du tombereau pendant la collecte des données de terrain. ¦ MOTS CLÉS amortissement rapide, camion de transport, fabricant d’équipement d’origine (FEO), jambe de suspension, suspensionINTRODUCTION Research basis for the paper This paper is based on the unpublished MSc thesis work of El-Sayed (2003), Santos (2007), and Soni (2009) under the direction of Dr. Tim Joseph within the oil sands–equipment interactions program (OsEIP). OsEIP is part of the Alberta equipment–ground interactions syndicate (AEGIS) surface mining research group, School of Mining and Petroleum Engineering, University of Alberta. The aforementioned work spanned a decade of progressive studies into rapid dampening suspension systems, leading to the scale performance indications highlighted here. Although this paper uses a specific Caterpillar 797B suspension strut for field monitoring and as a basis for scale prediction of a modified rapid dampening suspension strut design, the design scaling principles used here could be applicable to any such design change consideration for an oleo-pneumatic suspension system."

Jan 1, 2019

By B. S. W. Buffam

"The property of Aunor Gold Mines, Limited, is in Deloro township, Ontario, about 3 miles southeast of Timmins. It consists of a group of eleven claims between the Buffalo Ankerite and Delnite mines.In the autumn of 1909, two brothers, John A. and W. S. Mitchell, joined the 'gold rush' to Porcupine. By the time they arrived the township of Tisdale, in which the Hollinger and Dome discoveries had been made, was staked solid but they managed to locate four claims in the northern part of Deloro township. Sufficient surface work was performed to bring the claims to patent in 1915. Following the Porcupine fire the Mitchells left the north to follow the oil developments in southwestern United States. In 1935 because of the rise in the price of gold and the successful development of the l3uffalo Ankerite and Delnite mines, they returned to Timmins and organized Augite Porcupine Mines, Limited, which combined the original four claims in Deloro and two adjoining claims controlled by Montreal River International Silver Mines, Limited. There were few rock exposures on the property, and as the overburden was generally deep surface exploration was impracticable. A programme of diamond drilling was, there; fore, undertaken in an endeavour to locate the western extension of the orebearing formation of the Buffalo Ankerite mine. This drilling was started in August 1936, and 5 months later ore was intersected at a depth of 500 feet on the south boundary of the property."

Jan 1, 1954

By J. Bardinas

"The use of autogenous mills has become widespread, owing to their capacity and favorable capital and operating costs. Optimal operation of these systems is critical, given their high energy consumption and effect on downstream processing. A considerable effort has been spent over the years in the development of advanced control systems to achieve a better performance in this regard. However, despite significant advances, the problem still remains challenging, owing to the nonlinear behaviour of the system with respect to the mill variables, and, the unmeasured ore variability come from the mine.The mill load, in particular, can be seen as a state variable of the mill, which could be important for; modelling and control, and, important insights into the mill behaviour. In this investigation, time series cluster analysis was performed using online mill load measurements in order to identify the different control states of the mill. More specifically, this time series was divided into short non-overlapping segments. A distance matrix was set up for each segment and the information was captured by means of textural features, similar to that used in multivariate image analysis. These wavelet and grey level cooccurrence matrix features could subsequently be used to rapidly identify the normal operating conditions from the feed disturbances in the mill.In principle, the methods and models presented here, once suitably validated and calibrated, could be used in online process monitoring of autogenous mills. They also could serve as a foundation for developing more advanced process control models."

Jan 1, 2016

By F. H. Samuel, J. E. Gruzleski, S. Valtierra, H. W. Doty, F. J. Tavitas-Medrano

319-type cast Al-Si-Cu-Mg alloys are commercially important due to their popular use in automotive applications. Artificial aging heat treatments are commonly performed in these alloys to achieve precipitation hardening and, therefore, improve their mechanical properties. The present work was carried out to investigate the effect of conventional (at a constant temperature, as specified by the standard T6 heat treatment regime), and non-conventional multi-temperature and interrupted aging cycles on the hardness, tensile and impact properties of two 319-type alloys (with and without Sr+ Mg additions). The results show that certain multi-temperature aging cycles have a more favourable effect in improving some mechanical properties than conventional cycles.

Jan 1, 2006

By Bruce Regensburg

As trucks become larger and larger, haul roads take on a more significant role in mining costs and economics. The School of Mining at the University of Alberta has compiled a design manual for haul roads using both empirical and theoretical information. One section of this manual deals with the economics of haul road construction. While many mines look only at the construction costs of haul roads, this paper looks at all associated parameters including construction costs, removal costs, timing, truck productivity and width implications. The authors demonstrate the method to determine the most appropriate quality of road for different road conditions and life spans.

May 1, 2001

By C. V. Corless

THE origin of various types and groups of ore deposits was some years ago a subject of much controversy. To this statement the copper-nickel deposits near Sudbury afforded no exception. Not since the Report of the Ontario Nickel Commission, in 1917, has there been any serious discussion of the origin of this very important group. This may be because, from the opening-up of Murray mine by the British America Nickel Corporation until the recent work at Frood mine, no new ore-body of importance has been developed in the district. The controversy fifteen or twenty years ago between those who favoured the theory of magmatic segregation, among whom Dr. A. P. Coleman was the leading exponent, and those who considered that most, if not all of the Sudbury deposits could more satisfactorily be accounted for by the theory of replacement, will be remembered by many members of the Institute. Perhaps, as too often happens in controversial discussion, each side tended to overemphasize the importance of those geological phenomena which seemed to be most easily accounted for by the theory it favoured. A more balanced view would perhaps admit that replacement was probably predominant in the formation of most of the offset deposits, and magmatic segregation in that of most of the marginal deposits . But there is danger in generalization. Each body of ore should be studied by itself, and no general conclusion of this kind should be allowed to warp the judgment in making such a study.

Jan 1, 1929

By E. S. Moore

"The Michipicoten-Goudreau area, bordering on the northeast corner of lake Suferior, has had a tectonic history related to that of the geosyncline occupied by this lake. This basin has been a major structural feature in the Canadian Shield since at least late-Precambrian time. It has been extensively faulted and was the centre of great igneous activity in the Keweenawan feriod . Many of the faults, folds, dykes, and sills in the surrounding regions tend to head directly or indirectly into this basin. Some of the faults in the Michipicoten-Goudreau area appear to run under the eastern part of lake Superior just as the large Keweenaw fault in Michigan extends into the lake on the south side. Some of these faults may even be extensions of or counterparts of the faults on the south side of the lake. Another set of faults in the Michipicoten-Goudreau area runs nearly transverse to some of these major faults, and it is evident that in some places movement has recurred at a later time on faults formed in an early period.STRATIGRAPHYThe rocks of this area, with the exception of Pleistocene and Recent formations, are all Precambrian:"

Jan 1, 1954

By K. Sun, S. A. Argyropoulos

The assimilation and the exothermic behavior of Zn-Zr metallic powder compacts into molten aluminum was studied by measuring simultaneously the temperatures inside at the centerline of the compact, at its surface, and inside the molten aluminum bath, as well as the net downward force acting on the compact. In addition, the exothermic behavior of these compacts was also investigated in an argon protected atmosphere. The temperature rise inside the compact increases significantly with the mass ratio of zirconium in the compact and to a lesser degree with the aluminum bath temperature. Experimental results on the recovery of these compacts in molten aluminum will also be presented.

Jan 1, 2008

By R. A. L. Drew, F. Jalilian, M. Jahazi

Joining of superalloy Inconel 61 7 with a foil interlayer using transient liquid phase bonding (TLP) technique was studied. Inconel 617 is a solid solution, Ni - Cr - Co- Mo alloy with an exceptional composition of high temperature strength, oxidation, carburization resistance and thermal stability. In this investigation, two bonding temperatures, 1065°C and 1150°C, and two interlayer thicknesses with joining times varying from 5 minutes to 24 hours were employed. Experiments were carried out using nickel base interlayer (A WS BNi-3) with boron as the melting point depressant (MPD) element. Joints were characterized using optical microscopy, SEM, FEG-SEM, EBSD, XRD and microhardness. The results indicated that the rate of elimination of the liquid phase with increasing the bonding temperature, holding time and decreasing the thickness of the interlayer increased. The main precipitates in the diffusion layer had platelike and blocky morphologies for both bonding temperatures and all holding times.

Jan 1, 2006

By Masatsugu Morimitsu

This paper introduces new technology of oxygen evolution anodes which can be applied to produce copper, zinc, cobalt, and other metals by electrowinning. The anode consists of nano iridium oxide particles dispersed in amorphous tantalum oxide matrix as a catalytic layer formed on a titanium substrate. The anode can reduce oxygen evolution potential by 0.25 to 0.55 V compared to commercially available lead alloy anodes and can suppress unwanted side reactions such as manganese oxyhydroxide, lead oxide, cobalt oxyhydroxide which occur during oxygen evolution in the electrowinning solutions. This technology is effective for environmentally friendly electrowinning processes with low energy consumption and less anodic deposition.

Jan 1, 2011

By P Kovacs, D. L. Flock

For the purpose of reservoir-performance calculations a balance can be made between the materials with-in the reservoir and the production from the reservoir. The material balance equation, a relationship which holds under or near equilibrium conditions, has been used in many forms by the Petroleum Engineer for the determination of initial oil-in-place in the reservoir and the calculation of performance into the future. One of the more recent methods developed by Tracy, utilizes a modified form of the Schilthuis material balance. In the latter case, values of incremental production are assumed for a particular pressure drop, a value of the gas-oil ratio found and a check of this estimate made by calculation"' the initial oil-in-place. Tracy's method utilizes an estimation of the instantaneous gas-oil ratio and by trial and error a value of the gas-oil ratio is

Jan 1, 1961

By J F. Davies

A review is presented of the fundamental differences between the Superior and Churchill geologic provinces. Structure, lithology, grade of metamorphism and a single recent age determination suggest that the Flin Flon -Snow Lake and Lynn Lake belts are remnant blocks of originally Superior rocks lying within the Churchill province. Major mineral belts occur along the main boundary between the Superior and Churchill provinces (the Thompson -Moak Lake nickel belt) and within the remnant Superior blocks inside the Churchill province (Fiin Flon -Snow Lake and Lynn Lake). During the Hudsonian orogeny, metamorphic gradients must have existed across the Churchill-Superior boundary and between the remnants of Superior rocks and the enclosing gneisses of the Churchill province. It is possible that not only the unusual nickel deposits of the Thompson belt but also the base metal deposits of the Flin Flon -Snow Lake and Lynn Lake districts are due to redistribution, or diffusion and migration of metals to areas of lower-grade metamorphism during the Hudsonian orogeny.

Jan 1, 1964

By G. Diaz

Técnicas Reunidas (TR) has been involved for over 30 years in the development of process technologies for the recovery of zinc from different primary and secondary feed materials, such as the ZINCEXTM process. Because of the complexity of the feed mineral resources, solvent extraction (SX) is an invaluable technique to concentrate and purify zinc solutions. When applied to a pregnant leach solution, solvent extraction can produce an extremely high quality zinc electrolyte, suitable for obtaining SHG zinc ingots, after electrowinning and melting and casting processes. However, the high affinity of most organic extractants for Fe(III) poses a serious problem, which may adversely affect the zinc extraction process. Different methods may be applied to deal with the negative effect caused by Fe(III). An acid regeneration step and electro-reduction stripping have been considered as the most viable techniques to remove the iron from the organic phase. This paper describes some findings of Técnicas Reunidas in the area of zinc solvent extraction, especially on removing Fe(III) from the organic phase.

Jan 1, 2006