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Jan 1, 1997

By Anibal Gastañaga

La determinación del cuarzo es un problema dentro de la Higiene Industrial, puesto que este mineral se convierte en una de las enfermedades ocupacionales causadas por la inhalación de pequeñas partículas de cuarzo encontradas en el aire. En ese sentido, el presente texto señala la importancia y peligrosidad de los polvos del mineral a través de la determinación cuantitativa de cuarzo en los polvos industriales, ya que el riesgo de adquirir silicosis es proporcional a la concentración de cuarzo en los polvos ambientales. Existen tres métodos para la determinación cuantitativa de cuarzo: El método químico, el de difracción de rayos X y el petrográfico. El método que presenta mejores beneficios es el de N. A. Talvitie, puesto que se basa en la propiedad del ácido fosfórico, donde se forma complejos solubles en agua con los silicatos y óxidos metálicos, quedando el cuarzo prácticamente inalterado.

Aug 1, 1955

By A Prinsloo, R Tewu

Automatic control of semi-autogenous grinding (SAG) mills has often been considered complex. Recent experiences at Century Zinc (worldÆs second largest open pit zinc mine) refute this. Together with operating knowledge and appropriate control techniques high quality control is achievable. In this application model-based, constraint, and multiple output control were employed. The control was implemented using standard blocks in the plant DCS. The resulting overall control strategy fulfils the operating objectives and controls the mill with minimal operator involvement over 95 per cent of the time. Previous campaigns using expert systems and complex DCS based control have lacked durability. Their fall into disuse is briefly discussed.

Jan 1, 2009

By Jean-Sébastien Kroll-Rabotin, Éric Climent, Florent Bourgeois

"Falcon concentrators are enhanced gravity separators designed for concentrating fine and ultrafine slurries. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidisation water. In a former study, we investigated the physical mechanisms that govern the transport of ultrafine particles (in the range 10 to 80 µm) inside Falcon UF concentrators, and concluded that separation efficiency is governed by differential settling. Initially, we derived and published a predictive model of the partition function under dilute conditions. The present paper proposes an extension of the initial model to concentrated ultrafine suspensions for application to industrial scenarios. The paper discusses how hindered settling has been added into the initial model to account for solid concentration effects. The modified model is tested against experiments carried out with a laboratory scale UF Falcon concentrator from dilute conditions up to 30 vol%. A good agreement between measurements and model predictions is obtained, which confirms that our hypotheses about the physics of separation inside a UF Falcon separator remain valid even at high concentrations.INTRODUCTIONThe Falcon concentrator is a fast spinning bowl that is fed at its centre of rotation. It uses centrifugal force to separate particles that are transported inside a thin liquid film that flows upward along the inclined wall of the bowl (McAlister and Armstrong, 1998). Due to differential settling, dense and coarse particles are concentrated inside the bowl whereas light and fine particles are rejected with the overflow stream. The fast rotation speed of the bowl yields high centrifugal force several hundred times the attraction of Earth. Despite the thinness of the liquid film (between 100 µm and 1 mm with a Falcon L40) where separation takes place, the Falcon concentrator can treat high flowrates (up to 30 L/min). At the bottom of the bowl, an impeller transmits the bowl rotation to the feed, which drains upward by centrifugal force as soon as it hits the base of the spinning bowl (Figure 1)."

Jan 1, 2011

The Greymouth Coalfield contains New Zealand's greatest known resource of bituminous rank coal. The coals are of very high quality, with low ash and sulphur contents and a range of other properties that makes them desirable for a wide range of uses. In fact only a few producers around the world today can offer coals with such exceptional properties. This suggests that Greymouth coal has potential as a premium export trading commodity. These assertions have been largely confirmed by a comprehensive exploration drilling programme funded by Mines Division û Ministry of Energy between 1979 and 1984. The program, forming part of the NZ Coal Resources Survey, was carried out under contract by Lime and Marble Ltd. The drilling of 49 deep, predominantly cored, holes at 1000 m intervals over the coalfield has generated a vast amount of data. It has shown the existence of three major potentially minable coal deposits containing 233 x 106, 33 x 106 and 15 x 106 tonnes of coal in ground. Investigations have at this stage only identified targets and these estimates represent 'in ground' resources, not recoverable reserves. Recent geological studies as well as past and present mining have clearly highlighted the problems posed by the complexity of the coalfield geology. The coalfield lies within a mobile zone in the earth's crust known as the Paporoa Tectonic Zone, which has been active from at least mid-Cretaceous to the present time. Currently this factor poses the greatest obstacle to the determination of mining possibility of the, defined deposit and ultimately will strongly influence any future mining development. The Greymouth Coalfield has, however, had a long and eventful mining history spanning the last 120 years, where 32.5 x 106 tonnes of coal has been won from over 100 mines. In spite of the problems facing development, the large quantities and exceptional quality of the remaining coal will act as a strong inducement to persevere with this difficult but potentially valuable resource.

Jan 1, 1985

By G. Gomez Ciments-Calcia

The sources of complaints by neighbours of the operating quarry are due to the 3 following causes : - Impulsional noises or air hoch wawes – Vibrations - D u s t How a blasting in a quarry operation is felt by neighbours cannot be measured solely by the various limits set by national and European regulations regarding vibrations and air shock waves (sound pressure).

Jan 1, 2002

CONTENTS:1. Introduct'iona. Previous Accountsb. Summary of Geologyc. Physiography2. Morgan Groupa. Lithologyb. Structurec. Faulting3. The Mineral Deposita. Descriptioni. Size and Shapeii. Compositioniii. Effects of Oxidationb. Relationship to Structurec. Genesis of Ored. Mount Morgan Orebodye. Sugarloaf Orebody4. Granitea. Mount Morgan Graniteb. Town Granite'c. Moonmera Granite5. Calliungal Beds6. Razorback Beds7. Acknowledgments8. References

Jan 1, 1952

By McLeod RL

The Tolukuma gold-silver prospect is located approximately 100km N of Port Moresby in the Central Province of Papua New Guinea (PNG). Epithermal "adularia-sericite" style mineralisation crops out over 1200m within an en echelon quartz veined zone 1 to lOm wide. At a 4g/t cut-off grade, a geological resource of approximately 1.47Mt @ 13.77g/t Au is indicated from 38 diamond drill holes completed since discovery by Newmont Pty Ltd in September 1986. At a regional scale, Tolukuma miner- alisation appears localised in a dilatant zone at the intersection of a 1150 magnetic structure, and the western margin of a N-S trending graben which is filled by a Pliocene volcanic complex contemporaneous with the Mt Davidson Volcanics 30km to the W. A l0km diameter circular Landsat feature, which may reflect magma emplacement at depth, occurs immediately N of Tolukuma and nearby mineralisation. Mineralisation at Tolukuma occurs in sub-vertical quartz veins at, or adjacent to the faulted contact between Pliocene basic and intermediate volcanics/intrusives, and quartz mica schists and phyllites of the Cretaceous Kagi Metamorphics. Most veins display evidence of multiple episodes of brecciation and textures indicative of cyclic boiling, including crustiform rhythmic banding and quartz pseudomorphs after platy calcite.

Jan 1, 1991

By T. K. Perkins, L. R. Kern, R. E. Wyant

Many factors influence the results of hydraulic fracturing to stimulate well productivity. Most of these factors have been studied and their effects discussed in the literature. However, the movement of sand through the crack during fracturing has received little consideration. Exactly where the sand goes in the fracture, how it gets there, and how this might influence results have not been studied, judging from published reports. To get an answer to some of these questions we have studied sand movement through a simulated crack segment in the laboratory. Although the work is preliminary, we have answered some questions about sand movement in a semiquantitative sense. We are reporting our results at this time in the hope of stimulating interest and further study in this important aspect of fracturing. LABORATORY EXPERIMENTS Fig. 1 is a schematic diagram of equipment used in this study. A segment of a vertical crack 0.25-in. wide was formed between two Plexiglas plates, and movement of sand in fluid through the crack was observed under various conditions. Sand and fluid were injected into the crack at constant rates. The top and bottom of the crack were closed so that the fluid flowed horizontally. Because of gravity most of the sand settled to the bottom before moving very far through the crack. If the fluid velocity exceeded a certain critical value, then all the sand injected was washed on through the crack even though it had settled to the bottom. When the fluid velocity was less than this value when sand injection was started, most of the sand which settled in the crack remained in place until enough of the area open to fluid flow was blocked by the settled sand to increase the fluid velocity to the critical value.. At this point all injected sand moved on through the crack even though it settled to the lower portion of the moving fluid section. All sand previously settled remained in place. When fluid velocity was increased at this paint by increasing fluid injection rate (without also increasing sand injection rate), some of the previously settled sand was washed out until enough area was open to flow that the velocity dropped to the critical value. Conversely, when the fluid velocity was decreased by decreasing the fluid injection rate (without changing the rate of sand injection), additional sand would settle until the critical velocity was again attained. In short, the critical velocity is an equilibrium value which the system will automatically seek, if possible. The equilibrium (or critical) velocity was measured under several conditions. The results of these measurements are shown in Pig. 2 where the equilibrium velocity is shown as a function of the amount of sand injected per minute. The points falling in the shaded band shown in Fig. 2 were obtained with water. The higher viscosities were obtained by adding CMC (carboxymethylcellu-lose). Data indicate that the equilibrium velocity is not very sensitive to sand size or transport fluid viscosity, or to sand injection rate (except at very low rates). Points connected by the solid CUrve in Fig. 2 were obtained with water and 20- to 40-mesh steel shot. The equilibrium velocity is apparently fairly sensitive to difference in density between particle and fluid. Only one run was made with a gelled fluid and that was gelled water at zero sand injection rate as shown in Fig. 2. (Measurements of equilibrium velocity at zero sand injection rate were made by filling the crack

In an earlier paper (Stanton, 1953) a brief account was given of the geological environment and structure of the Lloyd Copper Mine orebody, Burraga, N.S.W. The present paper is concerned with the chemical and mineralogical features of the ore from this mine.Investigation has been made difficult because of inaccessibility of the workings, which have been fallen in for many years. The exact positions within the orebody of the specimens described in this paper are known in only a few cases. The specimens examined are from the collections of the Mining and Australian Museums, Sydney, and from material collected by the writer from the upper parts of the mine and from various dumps about the old workings.However, no significant variations in the nature (as distinct from grade) of the ore have been mentioned in the old reports, or by Carne (1908) or Kenny (1928), so it is likely that the specimens examined are reasonably representative of the orebody as a whole.CHEMICAL CONSTITUTIONThe ore is of simple and apparently very uniform composition.It is essentially a copper ore, with minor amounts of zinc and very minor amounts of lead. Plotting of copper against zinc shows a more or less sympathetic relationship between these at least as far as 20 per cent. copper - the highest grade assayed during the present investigation. The trend of the plots indicates a Cu/Zn ratio of about 15/1 to this point. Lead is very low and extremely sporadic, showing no clear relationships with the other metals.MINERAL COMPOSITIONThe principal non-opaque minerals are quartz and sericite, and these are accompanied by smaller quantities of muscovite, calcite and biotite. Quartz is the most abundant mineral, occurring both as a C'onstituent of the country rock a quartz-sericite schist-and as veins. All quartz aggre...

Jan 1, 1955

By David Siskind

The authors studied small seismic exploration blasts for vibration characteristics and effects on structures in Mexico. Obtained were 267 three-component recordings of ground vibrations and structure responses from 62 test blasts at six single-story masonry structures. Charges were 4.55 kg (10 lb) of Vibrogel expolsive at depths of 20 and 30 meters. Initial blasts were 240 meters distant and proceeded towards the structures to as close as 5 meters. All blasts were in soil media in two basic types of terrain, low saturated areas and upland dry areas. Structural inspections were before, during, and after the test blasts.

Jan 1, 2002

By C. Scheffer

This paper describes a model that can simulate the behaviour of a pneumatic intensifier that is generally referred to as an ?air pump? (AP). The AP is used in many South African underground mines, and utilizes compressed air with pressures between 0.3?0.6 MPa to pump water up to pressures of 12?18 MPa. The high pressure water is used in numerous underground mines to pressurize props and roof bolts that act as safety and roof support devices. The simulation model reproduces the intensifier's operation under various conditions and therefore can be used to investigate the AP's sensitivity towards environmental conditions, design parameters (such as spring stiffness, plunger diameter, nozzle diameter etc.) and operating conditions. Model validation by comparison with laboratory experiments showed good correlation. The model can subsequently be used to investigate design changes aimed at improving the AP's performance and reliability over a wider range of operating conditions.

Jan 1, 2005

By K. N. Panigrahi

India bestowed with 6000km of the coastal belt, contains some of the richest and largest placer deposits with a mixture of heavy minerals like ilmenite, rutile, leucoxene, zircon, monazite, sillimanite and garnet. Each of the minerals is having economic value due to its inherent characteristics for industrial use in fields of paints, metallurgy, refractory, abrasive and so on. The reserves of titanium bearing minerals (ilmenite, leucoxene, and rutile) in the country is around 378 million tonnes. More than 90% of the titanium based minerals produced worldwide are utilised for making value added products in the pigment industries. Approximately 8 million tonnes of monazite reserves are available in the country from which several rare earth elements like cerium, neodymium, lanthanum, yttrium etc. can be extracted for use in several industries. The country contains a deposit of about 20 million tonnes of zircon, which is used in foundries, refractories, ceramics and chemicals. India has a reserve of 107 million tonnes of garnet and 131 million tonnes of sillimanite required for the abrasive and refractory industries respectively. Keeping in view the multifarious uses, the beach sand minerals are being exploited to have the economic growth of the nation. Although the process adopted for the separations are simple, the equipment involved are specially designed because of the nature of the material of construction. Starting from the spirals to magnetic separators, all equipments are manufactured outside India, which is not only costly, but the availability also takes much time for fulfilling the import formalities. Unlike open cast mining, beach sand mining is a environment friendly mining because dredging is implemented to cut and pump the loose sand through a slurry pump causing less damage to the surface topography as both mining and backfilling takes place simultaneously. Therefore all out efforts are made to explore the beach sand placer deposits in an economic manner to emerge as a leader in the global mineral industries.

Jan 1, 2005

By EDWARAD A. SIVEDENBORMG

REPORTS have been made at different times on the progress of water encroachment in the Frontier sands in the Salt. Creek oil field, Natrona county, Wyoming. All previous reports have, -however, been largely based on the position of water in the sands as determined by various physical tests. Subsequent information has been secured through a preliminary investigation of the porosity, grain size and degree of saturation of the Frontier sands. Also, a closer differentiation has been made between the waters encountered incident to the production of oil by means of chemical analysis. In view of the more recent developments there has been a need of a water encroachment map of the first Wall Creek based on a field survey and additional information acquired since the water encroachment map of the sand of 1926, by J. S. Ross and E. W. Henderson, petroleum engineers of the U. S. Geological Survey. The present report is confined to a study of the first Wall Creek sand and was written in connection with the preparation of the map, showing water encroachment in this sand. The first Wall Creek sand was the discovery sand in the field, the first well having been drilled in 1908. Its thickness averages 120 ft. and, varies between 90 and 160 ft. The sand is in the Colorado group of the Upper Cretaceous series and is further considered as a part of the Frontier formation found in other parts of Wyoming.

Jan 1, 1930

By N Phillips

Fosterville gold mine recently celebrated production of its one millionth ounce of gold based firmly within a history of refractory sulfide gold mining. Compared with other Victorian gold mines, the disseminated nature of the sulfide gold is a deposit style with low estimation variance combined with established processes to accurately delineate the controlling structures. The systems in place had been established and have worked effectively for the majority of the one million produced ounces.By the end of 2014, diamond drill campaigns targeting the lower Phoenix orebody at depths of 800 m below surface began showing a change to the nature of the gold within the deposit. Coarse visible gold within 0.5–2 m thick quartz carbonate veins were being intersected with regularity showing the emergence of a different zone of gold mineralisation.Data about the new and exciting discovery couldn’t be gathered fast enough, however, established systems and processes throughout the geology and processing departments were not developed to handle a coarse gold environment. Change would be commensurate with the size and scale of the discovery, and new learnings would need to be implemented quickly to keep in front of a mining schedule that was focused on producing tonnes due to the dropping grades of the sulfide ore.Gold assays being returned were showing that the gold nature was different to those of other Victorian deposits. Comparative to the highly nuggety nature of gold found in other Victorian goldfields, the fine grained gold accumulations were dispersed in relatively consistent narrow linear trends grading consistently into the hundreds of grams per tonne. New drill intersections were being returned by the day and research to find developed orebodies that had published information into how to handle such a rapid change yielded few examples.The challenge was to review and set new standards with regards to handling an orebody that transitioned the very nature of the gold being mined. This involved reviewing all steps in the estimation process including data capture and quality control and quality assurance through to mineral liberation through the mill. Difficulties also involved finding analogous orebodies that consisted of both free milling and refractory ores that were dealing with drill assays that were measured as percentages of gold.CITATION:Phillips, N, 2017. Fosterville gold mine – breaking the mould for Victorian gold, in Proceedings Tenth International Mining Geology Conference 2017, pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

A calibration of the Frantz isodynamic magnetic separator relates the current in the electromagnet and the transverse slope of the chute to the specific susceptibility at which separation is being effected. In addition to providing a rapid measure of the specific susceptibility of minerals and composite grains, the calibration provides a guide to operation of the Frantz isodynamic separator for mineral separation, and to the nature of composite grains. The most sensitive magnetic separation is obtained by using the highest practicable current and transverse slope, and the lowest practicable longitudinal slope.INTRODUCTIONProbably all minerals have a magnetic susceptibility measurable by sensitive techniques. However, magnetic separation between minerals which have low but different specific susceptibilities, and which for many purposes are considered essentially non-magnetic, has only become practicable with the development of the Frantz isodynamic separator.The construction and principle of this highly sensitive separator has been described by S. G. Frantz as an appendix to a description by 'Gaudin and Spedden (1943) of its application to the separation of sulphides constituting mill products.Various publications (e.g. Hess, 1949, Hutton, 1952) refer to its use in separating the mineral constituents of rocks, ores, and unconsolidated sands.As used in this study the Frantz isodynamic separator consists of a vibrating chute mounted centrally between the pole pieces of an electromagnet (Fig. 1). This unit may be inclined in any direction by the universal mounting, and the electromagnet current is continuously adjustable from 0 to 1·5 amperes.

Jan 1, 1957

By P. A. Mingione

"AEROPHINE@ 3418A is a unique sulfide mineral promoter produced by Cyanamid, based on phosphine (PH3) chemistry. It has proven effective as a collector for the sulfide minerals of copper and particularly lead (galena), as well as for secondary gold and silver values. AEROPHINE 3418A has widest application as a Cu and/or Pb collector for complex ores of Cu-Zn and Pb-Zn, which frequently have significant quantities of associated precious metal values. Advantages shown in the use of AEROPHINE 3418A are improved selectivities against Zn- and Fe-sulfides, increased precious metals recoveries, reduced total collector consumptions for Cu and/or Pb flotation, and increased flotation kinetics leading to higher recoveries of these values. Operating plant, pilot plant and laboratory test data from treating different ores are presented, demonstrating the advantages in use and preferred application of AEROPHINE 3418A.INTRODUCTIONCyanamid operates the only phosphine and phosphine derivatives plant in North America, located in Niagara Falls, Ontario. Specialty chemicals manufactured at this facility are used in many diverse applications, including solvent extraction reagents and textile flame retardants. A unique phosphine-based sulfide mineral promoter, AEROPHINE 3418A, is also produced. The origins of AEROPHINE 3418A promoter date back to the 1960's, when it was established that sulfide mineral collectors based on phosphine chemistry demonstrated efficacy. This new collector chemistry was found to provide flotation performance differing significantly from those of more traditional thiol collector chemistries such as xanthates, dithiophosphates, mercaptobenzothiazoles, thionocarbamates and those with xanthogen groups. Some of the advantages ultimately demonstrated by AEROPHINE 3418A promoter compared to these traditional collectors include:"

Jan 1, 1990

By E. O. RHODES

This report is one of a series written by members of the Solid Fuels Mission to Germany describing wartime developments in the mining, prepara- tion, and utilization of coal. This mission was organized early in 1945 under the auspices of the Technical Industrial Intelligence Committee, which cooperated with a counterpart British Committee. In some instances; engi- neers from other allied countries cooperated. The Solid Fuels Mission operated under the direction of a steering committee headed by Dr. C. J. Potter, Deputy Solid Fuels Administrator. The personnel of the mission consisted of H. F. Yancey, in charge, J. W. Buch, Thomas Fraser, L. L. Newman, and L. D. Schmidt of the Bureau of Minos; H. H. Lowry, Director of the Coal Research Laboratory, Carnegie Institute of Technology; H. J. Rose, Vice-President and Director of Research, Bituminous Coal Research, Inc.; and F. H. Reed, Chief Chemist, Illinois Geological Survey. E. 0. Rhodes, Manager, Development Section, Tar Products Division, Koppers Co., Inc., served on the mission for the Chemical Subcommittee of 1.I.I.C. in Europe. His assignment was the investigation of the coal-tar industry. In this connection he prepared this report on the German Low- Temperature Tar Industry as a companion to his provious report on the German High-Temperature Tar Industry (Bureau of Mines Information Circular 7409). Because of Mr. Rhodes' extensive experience in these fields and the impor- tance of the subject material to the coal producers and those utilizing coal-tar products, both reports are issued by the Bureau of Mines. Over fifty reports were written by the members of the Solid Fuels Mis- elon. These, together with microfilms of supporting data obtained in the course of the investigations, are on file at the Foreign Documents Group, Technical Reports Section, Bureau of Mines, Pittsburgh, Pa., where they are available for examination. Copies of reports available in printed form may be ordered from the Department of Commerce, Office of Technical Services, Washington 25, D. C. Check or money order accompanying order for printed reports should be made payable to the Treasurer of the United States. A Bibliography of Scientific and Industrial Reports, covering all ma- terials and subjects and giving instructions for obtaining the desired items, has been published weekly by the Office of Technical Services. Effective July 1, 1948, the Bibliography of Scientific and Industrial Reports will be prepared monthly instead of weekly and on a more selective basis. issue, which will be the first monthly issue, will be available about July The July month thereafter through June 1949. Annual subscriptions and orders for individual copies starting with the July 1948 issue should be addressed to the Department of Commerce, Office of Technical Servicos, Washington 25, ur, and be accompanied by chock or money order made payable to the Troas- Bibliof the United States. Annual subscriptions for monthly issues of the Bibliography of Scientific and Industrial Roports will be $10. Individual issues will cost $1 per copy. Foreign subscriptions will be $14 per year and $1.50 por copy. tions listed in the Bibliography of Scientific and Industrial Reports should All orders for reports in microfilm or photostatic type of reproduc- ורי

Feb 1, 1949

By R. Siy, O. Neiman, B. Hilscher

"A full-scale prototype of “Jameson Downcomer” technology has been installed and tested on a Tailings Oil Recovery (TOR) vessel in Syncrude’s Mildred Lake extraction plant. Jameson Downcomers are a type of mineral flotation equipment used in the coal industry that Syncrude has extended to the recovery of secondary bitumen in the oil sand extraction process. The TOR vessels are currently being operated as single-gravity separation vessels, in series with the Primary Separation Vessels (PSV’s). We have developed a model to differentiate between “floating” and “non-floating” bitumen in the PSV’s, and then applied it to verify that the current TOR performance only captures the “floating” bitumen by simple separation. The existence of “non-floating” bitumen provides an opportunity for recovery enhancement by means of the Jameson Downcomers. To achieve bitumen recovery enhancement, middlings slurry is withdrawn from the TOR vessel, and passed through a number of parallel Jameson downcomers, within which the slurry is accelerated to a high-velocity free jet, and impinged upon the slurry surface inside the downcomer, in the presence of air. The aerated slurry is returned to the middlings zone inside the TOR, resulting in an incremental recovery improvement of bitumen in the TOR. The operation of the downcomers is thought to produce suitably small air bubbles for the flotation of bitumen, either by fluid shearing during the slurry jet impingement, and/or by micro-bubble nucleation. This full-scale prototype design has met or exceeded the recovery expectations of the original Research piloting, recovering at least 40% of the non-floating bitumen. In Syncrude Extraction, this provides high business value by a separation efficiency gain achieved with modest expenditure. As well, the system has demonstrated excellent operability and maintainability.INTRODUCTION Syncrude Overview Syncrude Canada Ltd. is one of the largest producers of crude oil from oil sands. Our crude oil production facility has the capacity to produce over 15% of Canada's total oil requirements. To do this, we surface mine oil sand, extract the raw oil known as bitumen from the sand using water-based processes, and upgrade that bitumen into sweet light crude oil by fluid coking, hydro processing, hydro treating and reblending. Our final product, Syncrude Crude Oil (SCO), is sent by pipeline to three Edmonton area refineries and to pipeline terminals which ship it to other refineries in Canada and the United States. The Syncrude operation is comprised of four major technology areas: Mining, Extraction, Upgrading and Utilities. As well, Syncrude invests more than $40 million annually in science and technology, and is among the top 50 companies in Canada for Research and Development (R&D) investment. Syncrude holds 21 active Canadian and U.S. patents."

Jan 1, 2012

By McDonald G. G

In the deformation of a metal or a single-phase alloy all the crystals composing the metal after their shape in a similar manner as the metal in bulk and to about· the same extent. This is not the case in an alloy consisting of two phases of different resistance to plastic deformation. In such an alloy the two phases take part in the deformation approximately in inverse proportion to their hardness, at least at the beginning of the deformation. (1) The hardness difference becomes less in the course of the deformation and thereby the deformation more equal. The phenomena occurring during cold-rolling of some two-phase alloys have been investigated by H. Unckel who made statistical grain measurements of the degree of deformation of the two phases after various reductions by rolling and also microscopical observations of the flow in the neighbourhood of the grain boundaries. Because of the different relative flow of the two phases, the normal flow is disturbed in the vicinity of their boundaries, and some additional plastic flow must take place in these regions, the disturbance being levelled out at some distance from the boundary. The deformation of the two phases present simultaneously in the material should thus be different from that of each phase separately. The investigation of theimportance and the effects of this interaction of crystals of different phases is the subject of this paper.The deformation of crystals occurs as a gliding of crystal layers following crystallographic laws. In consequence of this slip the crystals composing the material tend to assume a common orientation, i.e. some crystallographic axes tend to become parallel to each other in all the crystals. The type of this preferred orientation depends on the type of the crystal and the working process. Any change in the mechanism of deformation results, therefore, in a change in the preferred orientation. Such a change in kind and degree of preferred orientation will, therefore, also occur if the interaction of crystals in a two-phase alloy gives rise to a mechanism of deformation different from that in the free phases.The present paper describes a study of the preferred orientation, the microstructure and hardness in wires of brass drawn to various extents.The development of preferred orientations in the two phases with increasing reduction was followed up in various layers of the wire.EXPERIMENTAL DETAILSThe experiments were carried out with a commercial 5 S.W.G. wire (0,212 in. diameter) containing: 62·7% Cu, 37·3% Zn, very faint traces...

Jan 1, 1941