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By Paul Toor

The operation of SAG mills is variable over time due to their continually changing liner shape, mass and subsequent load motion. However, this tends to be poorly accommodated in liner design and mill control, with only limited compensation made for this influence, usually in the first few weeks after a new liner is installed. With ever-increasing ore competency, increasing energy costs and decreasing ore grades, simplified design and operational approaches that compromise the achievable mill efficiency are no longer adequate. This paper presents a methodology that has been developed to measure and account for the changes in mill performance as the liner wears. This involves monitoring all liner profiles ? in other words the three-dimensional liner shape - over the life of the liner, then conducting controlled surveys at different stages of the liner wear life, and correlating the mill performance to the liner profiles. The measured liner mass is modelled to provide an ongoing meaningful load mass measure that excludes the liner mass.

Jan 1, 2012

By T. Feldmann, G. P. Demopoulos

The adsorption of gold complexes on inorganic metal oxides has been mainly discussed in geochemical literature, but it is also of interest to the hydrometallurgical industry. This is so because it could be responsible for valuable metal losses or because it could potentially serve as alternative adsorbent material to activated carbon in certain cases such as from hot and acidic process slurries. This paper constitutes an early investigation into this subject by focusing on the effectiveness of FeOOH, Fe3O4 and Al2O3 as sorbent materials. All tests were done in a batch stirred-tank reactor under atmospheric conditions with synthetic gold(III)-chloride solutions at 23°C and 80°C, in the pH range of 1.6 to 9.0. Detailed kinetic tests were performed at different pH values (3 and 6) on FeOOH and Fe3O4 with solutions having gold concentrations from 5 mg/L to 130 mg/L. The adsorption of gold was found to be best both in terms of kinetics and loading characteristics at 80°C and pH=6. This was explained by a change in Au(III)-Cl speciation from a gold(III)-chloride complex to a gold(III)-chloride-hydroxy complex. By far, magnetite (reagent grade chemical) yielded the best gold adsorption characteristics making it an interesting sorbent material for further development considering that it can be advantageously recovered from slurry streams via magnetic separation. On the other hand, the tendency of gold(III)-chloro complexes to adsorb on metal (hydro) oxides needs to be taken into account to minimize undesirable metal losses in chloride-containing leaching media.

Jan 1, 2015

By Ralf M. Kleine

THE property of Consolidated 1 Discovery Yellowknife Mines Limited, (Figure I) is situated in the Northwest Territories, approximately 50 air miles north of the town of Yellowknife. The mine is reached by a shaft which extends from surface to a depth of 4,000 feet, with working levels established at 1 50-foot intervals. Stopping operations are carried on throughout a vertical range of 2,000 feet, with both shrinkage and cut and fill methods being used, depending on the ground conditions. Production started in 1950 and milling is done in a 1 65-ton per day cyanide plant. During ten months of the year, the property is serviced entirely by air, utilizing charter aircraft from Yellowknife. A 4,000-foot runway near the mine was constructed from mill tailings. This strip is adequate to receive Bristol freighter planes carrying heavy loads. Other servicing is done by Otter aircraft, equipped with skis or wheels for winter and with pontoons for summer operations.

Jan 1, 1962

By A. D. Misener, L. G. D. Thompson

"IntroductionIt was shown by work previously reported that reliable geothermal gradients representative of various regions of the earth's, surface could he obtained from extended surveys of the rock temperatures in operating mines. These surveys showed the presence of anomalies in the isothermal levels and the existence of regions of regular behaviour. Below about 3,000 feet the temperature gradients became quite regular over the areas stud1ed. It is these regular gradients which are taken as representative of the region, wherever possible.The present paper describes the extension of this work which was undertaken to obtain further temperature gradients with a view to correlating them to other geophysical properties determined for the same regions. The additional data obtained have indicated possible reasons for the temperature anomalies. The experimental procedure was similar to that already described and was again made possible through the wholehearted co-operation of the management and the assistance of the personnel of the mines concerned. The research was entirely supported by a grant from the Research Council of Ontario.The equipment was a distinct improvement over that previously used and made it possible to take many more accurate temperature readings in a given time. Thermistor resistance thermometers were used, encased in silver sheaths and protected against damage by heavy copper casings. These were calibrated with a standard platinum resistance thermometer.The bridge used with these thermometers was one of a number designed and built by the Meteorological Service and designated M.S.C. Thermometer Indicator Type C-3. This very convenient and portable instrument operated from batteries in the instrument case. Multiple thermometer connections were provided so that rapid readings• of a number of thermometers was possible to accuracy of the order of 0.1°F. All electrical connections on the panel are covered with Dow-Corning ignition compound to prevent; electrical leakage due to moisture condensation. This, together with the high resistance of the thermometers and components of the bridge, gave much more reliable results than previously obtainable."

Jan 1, 1950

By J. C. Rudolph

"THE TOPIC on which I am speaking this afternoon is ""The Future of the Canadian Oil Industry.'' At the time of C + 100, we should take a searching look at ourselves, an honest appraisal of our achievements and a forthright accounting of our shortcomings as well as the uniquely Canadian aspects of this industry. I would like to put before you some of my views on the direction we are taking in the exploration field and in the production field. I would also like to speak briefly on some of our problems and the role of the various segments of our industry in solving these problems.First of all, let us look at the exploration picture. We are in the midst of an exploration boom. There were 133 seismic crews active in Western Canada this winter, the highest since 1957, land prices are appreciating rapidly, Canadian oil reserves increased + 16 per cent during 1966, there is a great demand for technical personnel of every kind and the whole industry, except the drilling segment, seems to be prospering. This surge of activity has its roots in two major occurrences. The first of these was the change in the pro-ration system in Alberta, the major producing province, accompanied by the change in spacing pat-terns. The proration change was designed primarily to encourage in-creased exploration and it has certainly had this effect. It has also had the unforeseen effect of put-ting everyone into what we, in the oil business, call ""elephant hunting."" In other words, the days of the development of barely economic, marginal fields are over. Oil companies today are only interested in high-reserve, high-productivity, high-quality reservoirs."

Jan 1, 1968

By F. Awotwe-Appiah, P. Koshy, A. Y. Fosu, J. Dankwah, J. R. Dankwah

Ghana currently exports its bauxite raw without any value addition. Gradual depletion of high grade bauxite (with high alumina content) and the emergence of low grade bauxite (with high iron oxide content) calls for novel and inexpensive ways to recover alumina from these low grade ores. Bauxite users have indicated their willingness to pay 10% to 50% higher for a corresponding reduction in impurities by a similar amount. This project therefore investigates the carbothermal upgrading of the Ghana Awaso bauxite using waste polypropylene as reductant in a locally designed gas-fired furnace. Composite pellets of low grade bauxite sample (assaying 45% Al2O3) containing pulverised waste polypropylene were formed, oven dried, placed in fireclay crucible and fired for 30 minutes. The magnetic fraction after reduction was separated by a Low Intensity Magnet and weighed. It was observed that up to 97% of the iron oxides (occurring as hematite and goethite) could be separated into the magnetic fraction as magnetite leaving a nonmagnetic fraction with over 98% Al2O3 as opposed to the 45% Al2O3 in the as-received bauxite sample. This research direction provides yet another simple but effective way for simultaneously upgrading low grade bauxite and recycling waste polypropylene, whilst at the same time decreasing the amount of waste material generated as red mud after the Bayer process.

Jan 1, 2015

"5.1. IntroductionThe sample preparation requirements for bulk analyses of platinum-group elements (PGE) are different from the requirements for ore microscopy and in-situ analyses. It is necessary that the initial sample collection results in as representative a sample as possible for both types of analyses. Ingamells (1980) believes, however, that sampling is always imperfect and that there is no such thing as a truly representative sample. Once collected, the usual low content and irregularly dispersed nature of the PGE require that samples for bulk analyses be made as uniform as possible, whereas in samples for ore microscopy and in-situ analyses the PGE must be concentrated. Because of the generally high specific gravity of platinum-group minerals (PGM), certain precautions must be taken, such as mixing the sample material in the bags prior to opening.5.2. Preparation forBulk Analytical MethodsThe principal factors that determine the size of the sample required for a bulk analysis are grade, heterogeneity and grainsize. Initially, the grade and sample heterogeneity can only be estimated and a sampling methodology is developed with experience. It is essential at all times, however, that the assayers have information about the source of the sample and the purpose for the analysis. Information on the grain-size, which can only be obtained through mineralogical analysis, is also very important for PGE analyses, but, unfortunately, is often ignored.5.2.1. Samples fromUnconsolidated DepositsConcentrations of PGE may occur in eluvial deposits as well as in a large variety of alluvial deposits, including those of fluvial and glaciofluvial origin. These deposits are often difficult to map and sampling is further complicated by the wide range, from sand-size to boulders, of the non-POE-bearing constituents, and by the irregular distribution and shape of the ""pay streaks"". PGE concentrations in unconsolidated deposits are largely composed of resistant Pt-Fe and Os-Ir-Ru alloys (cf. Cabri and Harris, 1975 and Raicevic and Cabri, 1976), thus making comminution to the usual-150 to -200 mesh somewhat unreliable, due to the malleability of these alloys."

Jan 1, 1979

By A. Dreimans

Tracing of 'float' against the latest ice-flow directions ha!' led to or assisted in discoveries of several mineral deposits in Canada at lP.ast since 1891, e.g., fluorite and corundum in eastern ?Ontario, Steeprock and Josephine iron ore in western Ontario, Malartic, Fisher-Quebec, and Lamaque gold ore, and Vendome zinc ore, in western Quebec, Sullivan zinc and lead sulphides in British Columbia, Orvan Brook or New Calumet sulphide deposit in New Brunswick, Lynn Lake nickel sulphide de-posit in Manitoba, etc. Pebbles or ore boulders whose source has not yet been found include diamonds in the Great Lakes region and ?sulphides in several localities in Ontario and Quebec. Complexity of transport of ore boulders, including non-glacial transport, may be the explanation. Tracing of ore boulders requires knowledge of the Pleistocene history of each particular area (ice flow directions, their ?changes during glacial oscillations, existence of pre-glacial lakes with ice-rafted boulders, later interference by streams, lakes, mass movements). Important also is distinction of till from similar non-glacial deposits and knowledge of the bed-rock geology. Quantitative methods, e.g., pebble counts, maybe applied while tracing magnetite, hematite, or goethite. Fragments of sulphide ores are less abundant in indicator trains, and quantitative methods are less suit-able for tracing them. Heavy-miner-al investigations may give good results for minerals resistant to weathering. Geochemical methods are of value only in the vicinity of ore deposits.

Jan 1, 1958

"AbstractThe Sedimentary Basin area of Western Canada, which lies between the Precambrian Shield and the Cordilleran mountain area, covers approximately 800,000 square miles. Sediments ranging in age from Cambrian to Tertiary are present and, of these, horizons in the Upper and Lower Cretaceous, Jurassic, Mississippian, and Devonian have yielded commercial oil and gas flows. Producing horizons in the Cretaceous and Jurassic are sandstone, while all those of the Palaeozoic are carbonate rocks such as red limestone or dolomite (bioherms). Shows of oil and gas have been encountered also in the Cambrian and Triassic sediments.The broad structural features of this vast expanse of sedimentary rocks are the Moose Jaw syncline, the Sweet Grass-Battle River arch, the Alberta syncline, the Foothills belt, the Rocky and Mackenzie mountains, the Great Bear-Slave Lake basin, and the Mackenzie Delta Basin area.This contribution outlines the .stratigraphy and structure of the Basin area, and gives examples of present producing oilfield structures and stratigraphic traps.Part 1.-Regional StratigraphyIntroductionThe vast expanse of relatively undisturbed sedimentary rocks of western Canada has long been recognized as prospective territory to search for oil and/ or gas. This search in western Canada dates back before the turn of the century, but, considering the size of area to be explored and tested, the effort an<l money expended upon it, which, before the recent discovery of oil at Leduc, Alberta, appeared large and fruitless, now seems almost ridiculously small. A check-up of effort and money expended prior to and since the Leduc discovery would undoubtedly reveal that more wildcatting and development has taken place during the last two and a half years than during all previous years combined. The figures would astound not only the average citizen, but many within the industry itself."

Jan 1, 1950

By D. V. Dorling, J. T. Bowker, J. A. Gianetto

Over the last few years, interest in the development and construction of large diameter, high pressure pipelines from the Mackenzie Delta in northern Canada and Alaska&apos;s North Slope has steadily increased as a result of the projected decline in recoverable natural gas from existing reserves in western Canada. The success of such enormous pipeline projects, which will require utilization of a strain-based design approach, is largely based on successful application of high strength line pipe steels, such as X80 and X100. To fully realize the economic benefits of high strength steels, welding processes and procedures must be developed to ensure that the requirements for high strength and good low temperature toughness are confidently obtainable in field girth welds used in the construction of such pipelines. This study aims to provide a better understanding of the factors that control weld metal strength and toughness for a series of mechanized X100 girth welds produced using a range of narrow-gap gas-metal arc welding procedures. The attainment of high yield strength (> 810 MPa) is considered to be an important target to ensure overmatching strength relative to the longitudinal property distribution of X100 line pipe steel. Some factors that have been considered in this evaluation include influences of gas-metal arc welding process variants (single and multi-wire) and changes in welding procedure specifications, including joint preparation. Key components of this work relate to the reliable measurement of weld metal strength variation through-thickness and as a function of position around the circumference of a given girth weld.

Jan 1, 2005

By G. E. Peacock

SIGMA MINES is situated in the township of Bourlamaque, Abitibi County, Quebec. It is a gold producer, and presently treats an average of 1,200 tons of ore per day, at a grade of approximately 0.18 oz. per ton recovered. The mill started operations in March, I937, at a rate of 300 tons per day. This was increased to 800 tons in I940, and to 1,000 tons by I943. The rate was cut back during the war years, but was brought back up to capacity by I948. The mill tonnage was in-creased to the present 1,200 tons per day in I960. The underground workings are serviced through No. 2 Shaft (Figure 1), which, with 24 operating levels, extends from surface to a depth of 3,317 feet. When depth exploration was decided upon, two possibilities were considered: (a) deepen the main shaft by1,000 feet; (b) put down a winze for the same distance.

Jan 1, 1962

By Donald J. MacNeil

The commercial carbonate industry of Cape Breton Island, Nova Scotia, began about eighty years ago with the opening of the Sydney steel plant. Significant carbonate deposits are confined to the Precambrian George River Grav" and the Mississippian Windsor Group. George River Group carbonates are thought to have formed as part of a stable platformal sequence. They are crystalline and lie within a dominantly quartzitic sequence. Of the four major sites for George River carbonates on the island, the most commercially promising are the dolomite at Kelly Cove and the limestone and dolomite at Glencoe. Kelly Cove dolomite has good potential for metallurgical, agricultural and fettling purposes; reserves approach 13.6 million tonnes. Windsor Group carbonates were deposited as marine sediments in basins formed by pre-Carboniferous fault blocks. Windsor dolomite reserves at Stoney Creek are only fractionally retrievable and hence are of little economic value. The Windsor Group's Irish Cove limestone has been quarried on a large scale since 1964; no undeveloped commercial deposits, however, remain in the group.

Jan 1, 1984

By W W. Moorhouse

A survey of recent literature indicates that sulphides occur in the volcanic rocks of the Archean, or in sedimentary rocks intercalated with the volcanic rocks. The thick sedimentary sections are generally poor in sulphides. Thus, the widespread pyrite and pyrrhotite mineralization in the Archean may be largely of volcanic origin. Introduction I N this paper, commercial base-metal deposits will not be considered, as they are dealt with in other papers of the Symposium. Instead, attention will be focused on those sulphides, often associated with graphitic argillites or tuffs, which have appeared in such embarrassing abundance in electromagnetic surveys of Archean areas. The data on which the paper is based are drawn from recent reports of the Ontario Department of Mines, the Quebec Department of Natural Resources and the Geological Survey of Canada. The information available from these sources is unfortunately limited, because sulphides commonly occur in sheared rocks, such as black argillites and tuffs, which rarely form conspicuous outcrops, and may not be exposed at all. Thus, in the absence of geophysical information, even detailed mapping may fail to reveal the presence of sulphide-rich rocks.

Jan 1, 1965

By D. R. E. Whitmore, J. M. Harrison

There are five logical stages in the search for orebodies in virgin territory, namely: (1) reconnaissance inventory of geology, and related investigations; (2) development of broad concepts as a basis for selecting regions of potential mineral deposits; (3) assessment of criteria leading to specific localities within these regions; (4) geo-physical and geochemical studies that will delineate small anomalous areas; and (5) stripping, drilling or other means of locating ore. In addition, the development of new means of extracting mineral resources and the finding of new uses play a vital role in our mineral industry. The continued growth of this industry will be largely governed by our ability to develop or to adapt new concepts and techniques, and to produce a greater number of scientists and engineers. It should always be remembered that more than one-third of Canada's exports are dependent upon our ability to find, develop and economic-ally exploit new orebodies.

Jan 1, 1967

By W. Gordon Muir

This paper deals with the exploration, development and current operations of the salt mine at Goderich, Ontario operated by the Sifto Salt Division of Domtar Chemical Limited. The rock salt is obtained from a bed 1,760 feet below the surface, 75 feet thick, extending under Lake Huron. Annual production is in excess of one million tons. Large mobile equipment is used. Details of this equipment, as well as the shaft layout, which permits the equipment to be lowered underground with a minimum of trouble are outlined. Mining, crushing and screening procedures' are rev1ewed. Reference is also made to productivity salt distribution and uses.

Jan 1, 1967

By C. Blais, G. L’Espérance

Characterization of second phase particles is important with regard to their influence on mechanical properties of materials. Analytical electron microscopy offers the possibility to achieve complete characterization of inclusions. Complete characterization of inclusions means quantitative evaluation of their chemistry and the stereological parameters. A characterization technique based on integrated microscopy and involving scanning electron microscopy, image analysis and energy dispersive X-ray spectrometry is presented. A discussion of the use of transmission electron microscopy and electron energy loss spectroscopy is also presented for the characterization of very small particles and compounds (>100 nm).

Jan 1, 1998

By Richard C. Corson

"Modern microprocessor systems make it possible to use several variables to anticipate changes in the process and to react with responses before upsets can be magnified by the process or by control action.Through tighter control, ""insurance"" can be eliminated from process set points without affecting product quality. In actual operation with a traveling grate furnace this control philosophy has produced savings of up to 20% in fuel consumption and 8% in fan power usage while producing a more consistent quality product.IntroductionA straight grate indurator, or pelletizing machine, consists of a continuo us moving train of pallets on which a feed stream of unfired, ""green"" pellets is deposited on a hearth layer o f fired pellets. This bed moves through several zones in the furnace where it is dried, preheated, fired and cooled by streams of gases which are pulled or blown through the bed by a series o f large process fan s. Control systems for straight grate plants are designed to maintain gas flow through the machine to ensure that sufficient time and heat are available to raise the temperature of the entire green bed to 1300°C where hematite bonding take s place.For the pas t two year s a new approach to control systems using microprocessor-based instrumentation has been designed and tested in an existing plant with a straight grate indurating furnace processing magnetite ore. The purpose of the test was to determine the most efficient operating setpoints for all levels of production above fifty per cent of design capacity. Through a combination of feed forward control, variable setpoints and additional loops, significant savings have been realized. Thus far the project has taught us much about control systems design and operation, energy utilization, and the process itself."

Jan 1, 1983

By J. Béland

"Three stages, each characterized by a particular sedimentation, magmatism, mineralization and deformation, are recognized in the geological history of Gaspe. The first stage led to the formation of the Taconian orogen, the second to that of the Acadian orogen and the third stage to the accumulation of a post-orogenic cover. The Taconian orogen includes volcanic and detrital rocks of Late Precambrian or Cambrian and Lower to Middle Ordovician ages in which ultrabasic intrusions have been emplaced. Folding is severe. Mineralization is of the Cr-Ni-Cu type, related to the igneous facies.The rocks constituting the Acadian orogen include two distinctive sequences corresponding to two successive sub-stages. The second substage began in Early Devonian time with the first pulses of the Acadian orogeny. The rocks of the first substage grade southward from a nearly platformal sequence to an assemblage implying less stability and spotty volcanism. The second substage was one of synorogenic deposition of elastic rocks, first in a marine environment and later under terrestrial conditions. Granitic intrusions, surrounded by aureoles of skarn and hornfels in which Cu-Pb-Zn mineralization is found, accompanied the Acadian deformation. The second-stage"

Jan 1, 1969

By C. S. Crocker

The Centennial orebody was discovered and named in 1970, Manitoba&apos;s centennial year. It is relatively small, about 2 million tons. Strike length varies from 400 to 600 feet and widths from 10 to 60 feet; dip is 75 degrees. Low grade and metal prices demanded low-cost mining, and the mine was developed for conventional sublevel stoping. As the ore lay entirely under a large lake, ground movement had to be avoided and the stopes were to be filled hydraulically. Late in 1973, vertical crater retreat mining was introduced at Inco Limited, Sudbury, to recover pillars between filled stopes. It proved satisfactory and the results were publicized by CIL, who developed the technique. The method seemed to offer some advantages and one stope at Centennial Mine was selected to be mined by VCR while production was maintained from blasthole stopes. The trial stope was safe and showed lower development costs, reduced drilling time, a favourable powder factor and good fragmentation. VCR mining is now an accepted method at HBM&S Co., Ltd., and its use is being extended.

Jan 1, 1979

By X. -G. Chen, K. Liu

Nowadays, great interests are rising on aluminum alloys for the applications at elevated temperature, driven by the automotive and aerospace industries requiring high strength, light weight and low cost engineering materials. As one of the most promising candidates, Al-Mn-Mg 3004 alloys is found to possess considerably high mechanical properties and creep resistance at elevated temperature resulted from the precipitation of a large number of thermally stable dispersoids during heat treatment. In present work, the effect of Fe contents on the evolution of microstructure as well as high temperature properties of Al-Mn-Mg 3004 alloys has been investigated. Results show that the dominant intermetallic changes from a-Al(MnFe)Si at 0.1 wt.% Fe to Al6(MnFe) at both 0.3 wt. % and 0.6 wt. % Fe. In the Fe range of 0.1 to 0.6 wt.% studied, a significant improvement on mechanical properties at elevated temperature has been observed due to the precipitation of dispersoids, and the best combination of compression strength and creep resistance at 300°C is obtained in the alloy with an intermediate Fe content (0.3 wt.%) with finest size and highest volume fraction of a-Al(MnFe)Si dispersoids. The superior properties obtained at 300°C makes 3004 alloys more promising for high temperature applications. The relationship between the Fe content and the precipitation of stable dispersoids as well as the materials properties has been discussed.

Jan 1, 2015