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By V. Taylor

"THE petroleum industry in Canada has been experiencing considerable difficulty in filling its manpower requirements during the last few years, and because of the rapidly expanding nature of the industry it is concerned about the supply that will be available to fill the needs of the future. As the oil industry is one of the more technically oriented industries, the most acute problem exists primarily in the field of profession-al/technical personnel. This is particularly true in the production and exploration side of the business, because it employs the highest percentage of this type of personnel. Let me illustrate this by giving you some figures reported by the Alberta Bureau of Statistics as of December, 1965 -out of a total of 9,641 male employees engaged in oil producing and geological and geophysical operations in Alberta, 3,021, or 31 per cent, were classified as engineers, geologists, geophysicists, managers and other professional personnel. No figures are available for 1946 to make a direct comparison of the expansion of the industry over the past twenty 466 years, but it is doubtful whether more than 100 professional/technical people were engaged in producing in Alberta at that time"

Jan 1, 1967

By N. W. D. Davis

"As I have recently carried out some further research on the Navan lead-zinc deposit data while working in Michel David's research team, I should like to add a few comments on the paper- ""Universal Kriging for Ore-Reserve Estimation- Conceptual Background and Application to the Navan Deposit"", by M. Dagbert and M. David (CIM Bulletin, pp. 80-92, February 1976). The first comment is that since this research has been carried out, important new theoretical advances have been made which make for an easier application of geostatistics to the non-stationary case (see Matheron0l). This is the theory of intrinsic random functions of order k. With the aid of this theory, it has been possible to write computer programs which can carry out automatically universal kriging, although so far such applications have been largely confined to automatic contouring and not to mining problems. However, if approached with care there is no reason why these methods should not be applied to mining problems and, in this case, an automatic study has been done on this data."

Jan 1, 1976

By L. Zhu, S. Kaierle, M. Dahmen, C. Zimmermann, T. Haubold, I. Kelbassa, C. Mattern

Application of integrally bladed disks (blisks) is of increasing interest in compressors of aero engines. Blisks are preferred due to their potential for size and weight reduction, for increased performance and for reduced manufacturing costs compared to conventionally bladed disks. In case of a damage the blisk aerofoils cannot be simply replaced. If the damage is beyond acceptance or blending limits refurbishment is possible only by scrapping the whole blisk assembly, or more cost effective by the application of advanced weld repair methods. Weld repair of blisk aerofoils is challenging as it affects a critical part with specific requirements regarding its mechanical integrity, and as the accessibility is usually limited. The paper describes the ongoing development of advanced weld repair processes as part of a comprehensive repair strategy which have been developed for small-sized blisk assembly to give competitive maintenance cost.

Jan 1, 2006

By M. E. Hurst

SINCE 1934 there has been a marked revival of interest in the Porcupine district, especially in the eastern portion of the area, where exploration on the property of Pamour Gold Mines has indicated the presence of extensive gold-bearing deposits. Owing to the prevalence of overburden and the limited amount of exploratory work that has been done, little information is available as yet concerning the distribution and structural relationships of the rocks in the area to the east of Porcupine lake. In order to throw some light on the structural conditions in this section, a brief discussion of the sequence and character of the formations in the better known, producing section of the camp has been included. It should be emphasized that this paper is a preliminary study and that, consequently, the conclusions expressed should not be regarded as final. The writer wishes to acknowledge his indebtedness to P. C. Benedict, whose study of the geological relationships on the Foley-O'Brien property has made possible a fuller understanding of the structure in the central portion of the area. The writer also wishes to express his appreciation of the information and facilities placed at his disposal by R. M. Macaulay and C. D. Stevenson, of Pamour Gold Mines, and by A. Bell, of Noranda Mines, Limited.

Jan 1, 1936

By A. Saki, P. Gebski, W. Ying

Industrial smelting furnaces are subjected to significant structural changes and deterioration caused by the conditions under which they operate. The current methods for the structural assessment of furnaces include visual inspections, analysis of thermal data, acousto ultrasonic-echo (AU-E) of the refractory lining and surveying of the key structural elements. Acoustic Emission (AE) non-destructive testing (NDT) technique has proven its capabilities for continuous monitoring of industrial installations and structures. Recently, Hatch Ltd. has been successful in applying acoustic emission for monitoring furnace tapblocks, and expanding the scope of the acoustic emission monitoring to the structural integrity of the entire furnace. The capability of detecting emissions related to the fracture development in the furnace shell, movement of the refractory, electrode arcing, combined with efficient source location algorithms makes an acoustic emission system a comprehensive tool for the real-time furnace integrity monitoring. In this paper the concept of such state of the art system for structural integrity assessment is presented. The initial results of the acoustic emission monitoring together with data analysis techniques are discussed.

Jan 1, 2011

By M. Fafard, F. Chevarin, D. Ziegler, H. Alamdari, M Kavand

"Carbon anodes, used in the Hall-Heroult process, are consumed by the electrochemical reaction to produce metallic aluminum. It is also consumed by parasitic reactions with air and CO2. The carbon anode is made of petroleum coke with different particle sizes, butts (recycled anodes) and coal tar pitch. The mixture of fine particles (less than 150 µm) of coke together with the pitch material forms a matrix, binding the large coke particles together. It is generally thought that the binder matrix is more reactive than the other anode constituents. This conjecture was not clearly proved in the literature. The present study is focused on the CO2 reactivity of binder matrix and anode constituents at 960°C, both under chemical regime (100% of CO2) and under a concentration gradient (diffusion). The apparent reaction rates of these materials were measured. The role of the binder matrix in anode consumption and its disintegration (dusting phenomenon) was discussed.INTRODUCTIONThe metallic aluminum production is one of the most important industries in Canada. The Al metal is obtained by the Hall-Héroult process. The principle of this process is the electrochemical reduction of alumina in molten cryolite carried out by an electrical current between carbon anodes and cathode at 960°C (Equation 1). The carbon anode is typically composed of calcined petroleum coke (65 wt.%) and recycled anode (called also butt, 20 wt.%) with coal tar pitch (15 wt.%), playing the role of cement to ensure the cohesion of the anode block."

Jan 1, 2016

By T. Urbancic, Eric von Lunen, G. Viegas, A. Baig

"The characterization of the failure process of induced fractures by hydraulic stimulation is fundamental to understanding the generation and evolution of the discrete fracture network within the reservoir. A more detailed analysis of the fracture mechanism can be a powerful tool for identifying fluid flow paths and proppant placement within the reservoir. For example, during the rupture process the energy release is partitioned into different physical processes for which the relative ratio is changed by the presence of fluids or rotations in the local stress field with relation to the frictional resistance in the fracture plane. Fractures occurring in the same host rock under the same stress conditions are expected to rupture similarly, independent of their size (self-similarity). Changes in the scaling relationships of fractures are indicative of a change in the failure process, host rock or in-situ stress. Correlation of failure process data with reservoir rock properties and the in-situ stress field will help identify regions within the reservoir with characteristic types of failures. Further correlation with hydrocarbon production data can be used to develop efficient treatment plans and production diagnostic tools.In this study we investigate the failure process of ~27,000 microseismic (M < -1) fractures induced during a hydraulic fracturing shale completion program in NE British Columbia, Canada by estimating static and dynamic source parameters, such as dynamic and static stress drop, radiated energy, seismic efficiency, moment tensor, fracture plane orientation, slip direction and rupture velocity. On average, the microseismic events have low radiated energy, low dynamic stress and low seismic efficiency, consistent with the obtained slow rupture velocities. Events fail in overshoot mode (slip weakening failure model), with fluids lubricating faults and decreasing friction resistance. Events occurring in deeper formations tend to have faster rupture velocities and are more efficient in radiating energy. Variations in rupture velocity tend to correlate with variation in depth, fault azimuth and elapsed time, reflecting a dominance of the local stress field over other factors.Further identification of spatial and temporal distribution of families of events with similar characteristic rupture behaviors, based on either rock formation, depth, source type, fracture plane orientation, stress drop, pad or proppant stage, may be used as a proxy for specific fracture network development and hydrocarbon production. This information may be used to determine reservoir properties, constrain reservoir geo-mechanical models with measured physical parameters, classify dynamic rupture processes for fracture models and improve fracture treatment designs. These will be the focus of future studies."

Jan 1, 2015

By D. Sharma, A. K. Singh, R. Singh, P. K. Mandal, M. Sarkar

"This paper deals with the stability investigations carried out at the XIVth seam of Jitpur colliery. The study was conducted to investigate the possible causes of roof cavity formation and face spalling at the middle slice face of block-3 longwall panel and to suggest remedial measures. The instrumentation and monitoring work was carried out in the panel over a period of nine months. On the basis of observations, it was found that if the maximum face span was reduced from the existing 4.8 m to 3.6 m, and if the face time schedule cycle was reduced from a maximum of 37 days to about 18 days, this problem could be eliminated. The recommendations of CMRI have been implemented in the middle slice face of block-4 panel with success. IntroductionModerate to steeply dipping, undisturbed seams of uniform thickness are worked by way of inclined slicing parallel to walls. In this method, the seams are treated as a combination of several moderately thick seams dipping parallel to roof and floor. Numerous variations of multislice mining have been used worldwide to get high coal recovery under local conditions of geology, subsidence control, proness to spontaneous combustion, statutes and economics. Multislice mining can proceed either downward descending from the roof or upward ascending from the floor. Ascending methods require backfill behind the working face to provide a base for the next slice. It is also adopted for surface protection against subsidence or mining under a massive roof. This paper presents a scientific study conducted in Jitpur colliery, IISCO where a 9 m thick seam is mined in three slices in ascending order with stowing."

Jan 1, 2002

By Muhammad Zaka Emad

ABSTRACT: Sublevel stoping mining methods with delayed backfill employs cemented rockfill (CRF) as a backfill material. It is used in underground mines to achieve ground control and reduce wall slough. In addition CRF serves to reduce development waste and provides a working surface for mining the upper levels. Efforts to optimize CRF practices have been published. This paper presents a detailed review of CRF practices in open stoping mining systems with reference to case studies. A new methodology is suggested in a simple stepwise approach, which can be adopted for site specific conditions. The need of laboratory testing and quality control program is discussed based on the published literature.

May 1, 2013

By G. W. Poling

"Construction, equipping and planned operation of a new laboratory for engineering-teaching and research in coal and mineral processing is described. This facility will provide approximately 1860 m2 (20,000 ft. 2 ) of laboratory space with nearly half devoted to a new venture in coal preparation. Two high-bay, overhead crane-accessed areas will accommodate major unit operations for each of the ""coal"" and ""mineral"" laboratories. COAL PREPARATION FACILITIES:The coal facility provides three main functional areas:(1) Sample preparation (drying, blending, crushing, screening) and sink-float washability testing.(2) Unit operations U1igh-bay, serviced by crane).(3) Analytical laboratories.(l) Sample Preparation and Sink-Float TestingBreaking or comminution of coal will be accomplished using a rolls crusher, a hammer mill, a jaw crusher, or a pulverizer. Capacity to prepare coal at rates of up to approximately 4 tph will be provided by some of these units. Large diameter (~0.5m) baths of heavy organic liquids will be available for sink-float washability tests on coal samples of several kg. Particle sizes of up to 25 mm can be tested in these baths. Smaller scale washability tests on finer samples will be accelerated by centrifuges."

Jan 1, 1980

By Eric Toh, Michel David

"Geo-statistics was born from mining problems: grades not being what was expected; more tons of waste than expected; in other words, dilution. Geo-statisticians now claim to have solved many of these problems, but the solutions seem to have a hard time being picked up by practitionners. One of the reasons may be the jargon which geo-statisticians are using. The reason for jargon is that obtaining solutions required a strict formulation in a statistical framework. Practicing mining engineers and geologists are not used to such a framework, and they are not familiar with the jargon. In this paper, the authors re-examine dilution in operating mines and answer two extremely practical problems, using practical language as much as possible. Can dilution be reduced by improving the quality of blast hole samples? How many samples are needed to obtain a good ore-waste discrimination, i.e. to reduce dilution to acceptable levels? Citing real situations, this paper will try to show how fairly simple concepts can be used to answer both problems. It will try to present the solut ions using a minimum of jargon, even if the theoretical solution could be obtained in a few precisely worded paragraphs.The two problems considered are the following: the first one was encountered in the Panguna deposit of Bougainville Copper Limited, P.N .G., but it occurs in every open pit operation where selective mining is required. As the cut-off is lowered, more and more mining occurs in marginal areas. Grade control is mostly based on the grades obtained from blast holes, hence, it is essential that the quality of the blast hole samples be as good as possible in order to reduce dilution, waste being sent to the mill and ore being sent to the waste dump.The second example stemmed from the grade control technique used in many gold open-pit operations in Western Australia: channels are cut on lines 5 m apart and assays are taken every metre. The pattern in the same regardless of rock type, whether one is in the oxidized zone or not. The number of samples to be treated is enormous, hence, the question arises how to find an acceptable sampling grid, and whether changing it can reduce dilution at an acceptable cost.A solution will be given to each problem separately, although in fact it could be seen that the formal framework is the same in both situations."

Jan 1, 1989

By J. Olaf Sund

"THE November issue of the Bulletin carried in it ""Origin of the New Bruns1viclc Gypsum Deposits"" by J. Olaf Sund. This paper was a digested account of a Master's thesis at the University of New Brunswick which was a very useful compendium of information of gyp-sum in New Brunswick. It was a warded the President' s Gold .Medal and the First Prize in the Graduates' Section of the Students' Essay Competition. The present writer presents his congratulations to the winner of the competition. At the same time he must comment on the use of certain terms and on certain conclusions presented in the paper.The term ""unconformable"" has been used in several places in the paper to describe the relationship of gypsum to anhydrite in various deposits in New Brunswick in a sense which is quite alien to the accepted meaning. It has long been known tl1at the gypsum at the surface or near the surface in deposits in the Atlantic Provinces has come from hydration of anhydrite by surface and ground waters. The gyp-sum must be looked upon then as an alteration or even a weathering product. It cannot in this sense be called ""unconformable"" and thus arguments using the word in the accepted sense are invalid."

Jan 1, 1960

About Barrick Paste Backfill at Barrick Goldstrike Rodeo Paste Plant Cyclone Lab Testing Challenges and Lessons Learned Future Barrick Projects

May 1, 2013

By F. Rosenblum, P. Spira

"Self-heating of broken sulphide ore or waste rock underground can lead to ignition and cause serious problems in a mine operation. An extensive study has demonstrated that it is caused by oxidation of certain species of pyrrhotite. Self-heating was found to take place in two stages, first progressing from ambient temperature to 1000C with exothermic formation of elemental sulphur in the presence of moisture and oxygen, and proceeding to a second stage in which the sulphur oxidizes to SO2. Ignition may eventually follow. An apparatus was developed to assess the propensity of sulphide rock to self-heating and the potential for hazardous behaviour. The effect of temperature, time, rock size, and surface treatment with chemicals is presented. On the basis of these results, possible approaches for preventing a runaway reaction are suggested for further investigation.IntroductionThe oxidation of sulphide ore, waste rock or tailings backfill, which may cause hazardous conditions underground through heating, oxygen depletion and, in some cases, fire, is well documented (Farnsworth, 1977; Ninteman, 1978; Rosenblum et al., 1982; Reimers, 1987). The self-heating mechanism, nevertheless, has not been satisfactorily explained. The onset of heating from ambient temperature, in particular, has not drawn the attention of researchers. In the course of a previous study (Rosenblum et al., 1982) aimed at finding a method to assess the hazard from using sulphide tailings as backfill, the authors developed an apparatus to measure self-heating rate under controlled, near ambient conditions. This has since provided decisive information in backfill investigations in the Noranda Group.The test methodology devised for tailings failed to predict self-heating in a broken waste rock known to be active. Upon repeated testing, however, a freshly crushed sample began to exhibit appreciable heating and oxygen uptake (Fig. I). After 14 tests, the self-heating rate reached a plateau of about 4O°C/h and then fell progressively to < 5°C/h after 30 tests. It was hypothesized that weathering in the presence of moisture and oxygen during testing had caused the onset of self-heating. Active tailings, on the other hand, are exposed to natural surface oxidation and need not be weathered to show heating. Based on this finding, a new apparatus was developed capable of simultaneously weathering a sample of rock and monitoring its self-heating behaviour."

Jan 1, 1995

By M. van de Vijfeijken

This paper will first give a short overview of the Copper Mountain project in British Columbia, which just has started commercial operation earlier this year. The grinding process with one 34&apos; x 20&apos; SAG mill and two 24&apos; x 39.5&apos; ball mills will be briefly discussed. All three mills are gear driven by a ring gear, dual pinion and two low speed synchronous motors. Copper Mountain has installed on all three mills, the new state-of-the art dual pinion mill drives. All the inherent operation and maintenance features of this drive technology will be discussed, as well as the advantage of having variable speed control also on the ball mills. The installation and commissioning of the mills and drives at Copper Mountain will be briefly reviewed. Finally the first field measurements on these low speed mill drives will be presented, with the main focus on the low mechanical stress impact of these mill drives on the pinion and ring gear, as well as the accuracy of the load sharing between the two motors.

Jan 1, 2012

By Dennis Martin

What is Borehole Hoisting Borehole Hoisting is the use of a hoisting plant to hoist rock, workers and materials or both, vertically through a borehole, between a mine level and surface or between two levels of an underground mine. Screen and bolt ground support on walls of 5.5 m diameter borehole hoisting shaft

May 1, 2013

By A. Taylor

This paper considers mineral processing in zero gravity dry environments typical of asteroids or comets. The electro-dynamic separation technique using pneumatic flow systems is explored. Pneumatic delivery of solids is used because of extreme temperature changes and the possible scarcity of water. The present earth-based process and how it can be modified for these conditions is examined.

May 1, 2001

By W. J. Przybylowicz, V. M. Prozesky, D. de Bruin

"The common style of gold mineralization in the Basal Reef and other auriferous conglomerates of the Witwatersrand Supergroup comprises clusters of gold grains occurring interstitially to quartz and pyrite pebbles as well as gold accumulations attached to the surface of and infilling hairline cracks and fractures in round, compact, detrital pyrite. The latter textural association is generally interpreted as a result of remobilization of originally detrital gold during regional metamorphism and related hydrothermal fluid circulation. There is general agreement that, although gold solubility was low, ore modification occurred during the metahydrothermal event, but uncertainty exists about the magnitude and scale of gold remobilization.Micro-textural and chemical investigation of compact round pyrite and associated gold accumulation has established that gold is preferentially deposited on chemically heterogeneous pyrite surfaces. Combinations of alternating high- and low-As zones in pyrite result in mixed np-type conductivity accompanied by electron exchange and the reduction-driven deposition of gold at the cathode. This model does not explain gold accumulations which are not immediately linked to chemical heterogeneities and it is inferred that an additional control on the deposition of gold was exerted by physical defects which lead to zones of increased charge density and/or areas of focussed conductivity. The inferred precipitation mechanisms suggest that submicrocopic physical and chemical controls are the important factors that determined the sites of gold nucleation and that precipitation mechanisms based on physicochemical changes of the hydrothermal system were not involved. The Basal Reef contains on average close to 5OJo of round, detrital, chemically zoned pyrite which provides a large number of electrochemically active pyrite surfaces. The extremely effective electrochemical precipi- . tation mechanism together with the low solubility of gold in Witwatersrand fluids is the main reason for the spatially restricted remobilization of gold in the conglomerate reefs."

Jan 1, 1994

By Norman B. Davis

Introductory Feldspar is one of the most important mineral products consumed by the various branches of the ceramic industry. In the manufacture of table ware, electric porcelain, floor tile, and enamels, it supplies the chief fluxing ingredients necessary to bond the other more or less inert materials together when moulded into desired shape and fired in a kiln. Feldspar is used in the manufacture of bottle glass as a means of introducing alumina in a form easily assimilated. It is also used in certain scouring soaps particularly designed for cleaning enamel and glass surfaces. Feldspar, as it finds its way to the trade, is not a single mineral but is rather a mixture of various proportions of the feldspar silicate series, either in natural intergrowth or blended in the milling process, to produce a desired result. It is often further modified by the presence of quartz in amounts up to 30 per cent. The table on the next page gives typical commercial analyses of feldspar from various sources. Canadian feldspar produced to date has consisted mainly of the high-potash, relatively low-soda, variety, and has enjoyed a good market in the United States for the manufacture of enamels, electric porcelain, and vitrified table-ware. About eighty per cent of the output has been exported to the United States, but, with increased milling facilities in Canada and changes taking place in domestic United States sources of supply, the proportion exported will be reduced next year.

Jan 1, 1931

By D. Mas Ivars, K. Suzuki, J. A. Vallejos

"A comprehensive geotechnical characterization has been undertaken at the El Teniente mine to describe and determine the rock mass behaviour strength properties of the primary copper ore. The Synthetic Rock Mass (SRM) modelling approach is used to simulate the mechanical behaviour of this heavily and unfractured rock mass. The micro-parameters of the model have been calibrated against mechanical properties and scaling laws for intact rock and veins, in order to represent virtual samples of four different geotechnical units. Results can be used to predict the rock mass scale effects, anisotropy, and brittleness properties that cannot be obtained using empirical methods.INTRODUCTIONThe primary copper ore at the El Teniente mine is described as very competent and massive, given that it exhibits a brittle behaviour (Rojas, Cavieres, Dunlop, & Gaete, 2000). This description is coherent with the geological description of the rock mass, which does not have discontinuities match as the definition provided by International Society of Rock Mechanics (ISRM, 1981). Only faults can be classified as discontinuities, but they are widely spaced. The primary copper ore has a high frequency of veins, where the cooper mineralization is hosted, these vein network structures are known as stockwork. Soft veins containing weak minerals as infill (chalcopyrite and anhydrite) control the disassembling of the rock mass during caving (Brzovic & Villaescusa, 2007).Presently, there are mainly two traditional methods used to estimate the strength of the rock mass: 1) determination of the strength envelope of the rock mass using scaling parameters from laboratory tests and 2) using numerical modelling based on back analysis of previous experiences of failure observed and measured in mining or civil excavations. The primary copper ore of El Teniente mine has no fractures; therefore, it is difficult to determine a rating that would enable to scale laboratory data, such as, RMR (Laubscher, 1977) or GSI (Hoek, 1994). This is the reason why the first option is not valid unless the entry data is manipulated or adjusted in order to obtain reasonable results. The second option requires, in general, a good characterization of a previous failure event in the rock mass, which is not always available. In recent years, new techniques of numerical modeling have been developed (PFC3D, ELFEN, Abaqus). Those methodologies are the third way to estimate the strength of the rock mass, but they are still in development. Particularly, the concept of SRM developed by Itasca is implemented in this study (Pierce, Mas Ivars, Cundall, & Potyondy, 2007; Mas Ivars et al., 2011), aiming to capture the real behaviour of the rock mass."

Jan 1, 2015