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By D. Berkley

Off-gas systems often become the limiting factor in production increase and environmental projects. Any upgrade or new off-gas project needs to address control instability issues, instabilities that can result in safety hazards, significant loss of system capacity and/or emissions to the environment [1]. In addition, the design engineer must optimize system configuration and equipment size for the new operating conditions, to have a technically feasible and economically viable project. Dynamic simulations can be used for addressing both the control stability and the design optimization issues. This paper illustrates how the dynamic simulation of transient processes and of their control system can be used in "real life" situations for these purposes, presenting the example of an electric furnace off-gas system design.

Jan 1, 2005

By J. Elbrond

"This paper describes qualitatively the progressive are losses and rock dilution in a mining project from the geological modelling to and including the concentration. A simple theoretical model of the net present value of a deposit, assuming a log-normal grade frequency function, is used to find the pair of decisions on rate of production and cut-off grade, which maximizes the net present value. Various degrees of ore losses and rock dilution are then applied on this optimum, and the resulting decreasing net present values are calculated, as well as the increasing cost of metal and the increasing metal losses as a function of are losses and rock dilution.IntroductionDue to a variety of uncertainties, to inevitable lack of precision in deposit estimation and in mine planning, and due to production constraints, ore losses and rock dilution occur throughout the many phases of a mining project. The phases range from the geological definition of the orebody, over the cut-off grade optimization and decision, over the design of the mining method and the actual mining to the ore dressing, where the final loss of valuable ore into the tailings occurs. Quantification of ore losses and rock dilution are mostly difficult if not simply impossible to obtain. At the end-phase an estimate of the total dilution may be obtained with some degree of precision by observations of the amounts and analysis of concentrate and tailings. It is much more difficult to estimate the total ore losses because the uncertainty of the geological modelling in the initial phase and in the mining phase is very difficult to quantify, despite the use of geostatistics for grade estimation.Many attempts at quantification of ore losses and rock dilution have been made and some examples are shown in Table I. Although they differ widely from each other, it is obvious from these figures that ore losses and rock dilution are significant and have considerable effects on the economical results of a mining operation. Life length, net present value, cost of producing metal and the loss of metal are all affected."

Jan 1, 1994

By James F. Archibald

A research effort has been undertaken, under WSIB sponsorship, to characterize the support capabilities of conventional and innovative spray-on lining materials for mitigating dynamic failure effects created by simulated rockbursts. Conventional spray support media, such as shotcrete and fibrecrete linings, and a variety of new spray-on lining materials (TSL?s), typically polymer-type thin coatings, were subjected to simulated rockburst influence. For baseline comparison, conventional rockbolt and boltand- mesh support products were also evaluated. Observation of lining performance was undertaken through completion of field scale support and rock detonation trials. Controlled blasting tests were conducted at the Queen?s University Explosives Laboratory to examine the effectiveness of the variety of surface coating agents for modifying dynamic rock spalling processes. All tests were performed upon largely undisturbed and homogeneous rock materials in highly repeatable fashion. Both conventional and innovative TSL-type surface lining materials were subjected to ?rockburst? exposure in rigorously-controlled blast trials. All blasts were observed seismically and photographically to provide detailed information concerning rock motion, surface fracturing, ejected fragment motion and support liner survivability characteristics. These material comparison trials were performed to assess the relative effectiveness of a wide range of currently-available area support techniques for suppressing hazards associated with dynamic rock ejection. The results of this study validates that thin, sprayon linings may be equally as effective, and often better, than conventional support materials at mitigating rockburst or like damage in highly stressed mine environments.

May 1, 2003

By Derek Perkins

"Brenda Mines Ltd. operates an open pit copper and molybdenum mine located in south central British Columbia. The main economic mineralization is chalcopyrite and molybdenite. Pyrite, galena and sphalerite are also present in varying quantities. The mineralization is present in small veins and fractures in a porphyritic quartz diorite host rock.The mill processes approximately 30,000 tonnes of ore daily. The ore is crushed in three stages and then ground in conventional rod mill - ball mill circuits with cyclone classification. The cyclone overflow is fed to the bulk flotation circuit as a pulp with a density of 50% solids. The particle size distribution is approximately 35% plus 65 mesh. Bulk rougher and cleaning flotation produce a concentrate grading approximately 20% copper and 4% molybdenum. This concentrate is fed to the separation circuit, where the copper is depressed with sodium hydrosulphide and the molybdenum is floated. These products are further ground and then upgraded by column flotation. The molybdenum concentrate is pumped to the leach plant to reduce concentration of lead and copper. It is then washed, filtered, dried and packed for shipment to Europe. The copper concentrate is filtered, dried and subsequently shipped to Japan.Prior to November 1977, the mill flotation control was carried out by the assay laboratory using a Philips PW 1540 sequential x-ray spectrograph. The assay set consisted of twelve samples, analysed on a two hourly basis for copper, molybdenum, lead, iron and silica.In order to provide elemental composition information on a much shorter sampling interval and to produce speedier control analysis for automating process control, an Applied Research Laboratories PCXQ on stream analyser was purchased. The installation of this analyser, reduced the turnaround time of the control analyses from (2) hours to (20) minutes. At Brenda, the following assays are used in the mill control strategies."

Jan 1, 1989

By H. J. McQueen

The modeling of the extrusion of 6061 alloy and its composites with 10 to 20 vol% Al203 or SiC by two techniques. The uniaxial finite element method FEM (DEFORM" ) provided force-stroke curves and temperature rise over the range 450-500 °C, 2.6-5mm/s and extrusion ratios of 31 and 64. The traditional technique considers ideal work and redundant work as well as friction and uses average temperatures and strain rates. The two techniques are used to clarify each other and to extend the analysis to 400 and 350 °C. The calculated efficiencies are compared to measured values in extrusion trials and to values derived for 7075 extrusion analyses. The analyses are based on constitutive equations determined by torsion testing tests.

Jan 1, 2004

By R. A. L. Drew, G. Mendoza-Suarez, J. Filipi, R. Vintila, J. A. Kozinski

Economics and environmental considerations along with the increasing demand of hydrogen encourage development of novel technologies such as plasma processing of hydrocarbons and thermal cracking of natural gas. Plasma discharges, either in thermal or non-thermal regimes are expected to allow low temperature and fuel flexible on-site hydrogen generation. The main drawback of thermal plasma reformers is the high-energy consumption resulting from high-temperature operation. On the other hand, non-thermal plasma, generated by dielectric barrier discharge (DBD), is able to simulate the chemical reactions employing much lower energies than those required by thermal treatment processes. The non-thermal plasma process allows for instance, a direct conversion of methane into hydrogen and carbon black with no CO2 release. The focus of this research was on the GHG-free method of H2 generation in compact non-thermal plasma reactors using low, medium and high permittivity dielectric ceramics. A stable, non-thermal plasma was generated by placing a dielectric ceramic between two electrodes with a 25 thou gap and applying an alternating current of 1-5kHz and voltages of 4-8kV. In order to ensure energetic efficient plasmas, experiments were conducted to analyze the behaviour of different permittivity ceramics. It was found that the dielectric properties of a ceramic, when used in a DBD reactor, have a strong influence on the discharge characteristics, which in turn influence the power consumption. Higher dielectric constant resulted in higher conversion rates of methane (higher yield of hydrogen and carbon). At the same time, the mechanical properties of the dielectric material, which are closely associated with its processability, influenced its resistance to electron bombardment, as well as thermal and mechanical damage. Therefore a reliable ceramic should have good dielectric properties, in addition to good thermo-mechanical stability.

Jan 1, 2004

By Nosa O. Egiebor, Kafui Nyavor

"The effectiveness of sulphuric acid, nitric acid, and hydrogen peroxide pressure oxidation on the cyanide extractability of gold from a double-refractory concentrate is presented. Whileover90% of the sulphide content could be oxidized by either of the two acid pretreatments, only 65% was achieved by the peroxide oxidation. Carbon oxidation by both acid and peroxide pressure oxidation were less than 15%. Although the peroxide pressure oxidation pretreatment resulted in much lower sulphur and carbon oxidation, it gave pretreated residues with decreased levels of preg-robbing activities and higher gold recoveries during subsequent cyanidation, thus indicating some deactivation ofthe preg-robbing carbon during pretreatment with hydrogen peroxide. The refractoriness due to carbon preg-robbing activity was found to contribute more to the refractory behaviour of the concentrate than the occlusion of gold particles by the sulphide mineralization.IntroductionGold ores and concentrates are classified as refractory when a significant portion of the gold content cannot be extracted efficiently by conventional cyanidation, even after fme grinding (Weir and Berezowsky, 1984); (Demopoulos and Papangelakis, 1987). The refractory behaviour of precious metal ores and concentrates is generally attributed to two main factors: The presence of carbonaceous materials which could cause preg-robbing activity during cyanidation (Zaitseva et al., 1973); (Nice, 1971); Scheiner et al., 1971); (Eisele et al., 1983), or occlude gold-bearing minerals (Wells and Mullens, 1973); (Gasparrini, 1983); (Chen and Reddby, 1990), and the occurrence of sulphide minerals which can occlude gold, thus reducing the access of lixiviants (Schwartz, 1944); (Weir et al., 1986); (papangelakis and Demopoulos, 1990); (Michaelis, 1989); (Schweigart, 1965). When the refractoriness is due to a combination of these two factors, the ore or concentrate can be referred to as being ""double-refractory"". Because of the rarity of gold ores exhibiting this double-refractory phenomenon, only a few studies have been carried out on their suitability for pretreatment by existing techniques."

Jan 1, 1992

By Riggin P. R.

"IntroductionIndustrial Relations combines two very important relationships - employee relations and union relations.Employee relations always come into play when people are hired to perform tasks. Because mineral processing plants cannot be operated successfully without people, at least not yet, if they ever will be, employee relations must exist in an operatingplant.If the employees choose to be represented by a union, then a relationship with the union as an institution also comes into play. It is very important to note that unionization does not mean that the employee relationship is replaced by a relationship with the union. The latter is superimposed on the former, but it does not replace it. Similarities and overlaps in the two relationships will be present, some of which are of fundamental importance. Nevertheless, they are two different relationships and the reader should bear this in mind when reviewing those parts of this chapter which discuss unionization, collective bargaining, collective agreements, and work stoppages.These two important relationships, which we have chosen to combine and call industrial relations, have crucial roles to play in the social system which interrelates people performing the necessary tasks involved in the operation and maintenance of a plant. The technological organization - equipment, process layout and so forth - and this social system are interdependent and complementary. This chapter attempts to show that the potential level of effectiveness of both the technological organization and the social system depends on the recognition and nurturing of this nexus between them.Occupational health and safety and training are subjects for another chapter. But, both of these have been critical and longstanding employee relations topics . They are destined to take on added importance in the future. As issues in collective bargaining, they are also attracting increasing attention in all union relations. It is hoped that the reader will not isolate from industrial relations those topics which are being dealt with in another chapter. They are very much a part of it and we cannot refrain from making some reference to them."

Jan 1, 1989

By A. H. Lang

"The Cordilleran region of western Canada includes most of British Columbia and the Yukon and pares of Alberta and the Northwest Territories. The western part of this region was for about 50 years the principal mineral producing area of the Dominion. It lost this distinction in 1907 when production from the mines of the Canadian Shield took the lead, but it continues to provide about 15 percent of the total Canadian production. In 1945 the total mineral production of British Columbia and the Yukon was valued at $65,302,900, of which about 80 percent was derived from metals.This paper is intended to serve as an introduction co the more derailed Cordilleran papers. Part I includes a brief synopsis of the complex geology and diverse types of mineralization in the region and Parr II collates the main structural principles exemplified in the derailed papers, and draws some conclusions regarding the application of this information to prospecting."

Jan 1, 1954

By H. C. Rickaby

The Bannockburn gold area covers the four townships of Bannockburn, Argyle, Hincks, and Montrose, lying in the western part of the Matachewan district of Ontario (see Figure 1). The geology of these four town-ships was studied by H. C. Cooke of the Geological Survey, in 1917-18, and is shown in his map of the district. In the fall of 1930, a rich gold-bearing quartz vein was discovered in the northwest part of Bannockburn by B. S. Ashley. A prospecting rush followed the discovery; many claims were staked in the Bannockburn area, and, during the summer of 1931, a considerable amount of prospecting was done.

Jan 1, 1932

By A. Ignatieff

This is the first in a series of Coal Technology Reviews being prepared in accordance with a recommendation voted by the Coal Division in session at the Jubilee Meeting, Vancouver, April, 1948, that the Department of Mines and Resources be requested to arrange for publication by the proper Government authority of a Quarterly Review' of Coal Technology, for distribution among those concerned in the production and use of coal in Canada. This recommendation was subsequently endorsed both by the Council of the Institute and by the Dominion Coal Board. Further reviews (or digests) will appear at intervals in the Bulletin, or will be published and distributed by the Board which, meanwhile, has undertaken to distribute reprints of Mr. Ignatieff's review.-En. * * * The fields in coal mining technology which are considered to demand most attention and study at the present time are reviewed under the headings appearing below. Mechanization In the light of the growing shortage of skilled miners and the necessity of mitigating constantly increasing mining costs, interest continues to centre in mining methods and applications of mechanization chat will produce the maximum reduction of man power. The growth of strip or open-cut mining, also, is a consequence of this trend. Mechanization at the face attracts most attention and the trend is toward developing and adopting machines capable of cutting and loading the coal in one operation instead of having the separate operations of cutting, drilling, blasting, and loading. In Great Britain, where longwall mining is? the general practice, the A.B. Meco-Moore machine still receives much attention, and accounts describing its performance over reasonably long periods have appeared in the technical press.

Jan 1, 1948

By D. M. Ward

"The uranium deposits upon which the Rabbit Lake project story is based are located at the eastern margin of the Athabasca Basin just west of Wollaston Lake in northern Saskatchewan. This paper provides a general review of the exploration history for the major deposits and the influence of an expanding geological data base, which served to guide the continuing exploration programs.A brief description of each of the deposits is provided in order of their discovery and with emphasis upon their relative geological and mineralogical characteristics.The Rabbit Lake and Eagle Point orebodies are monometallic uranium deposits localized by thrust faults within the Aphebian Wollaston Group. The Cof/ins Bay A-zone, B-zone, and D-zone are polymetaflic U, Ni, As, Co (Au , Ag) deposits located within the Helikian Athabasca Group at its unconformable contact with the underlying Wollaston Group. INTRODUCTIONThis paper demonstrates the importance of applying the accumulated geological knowledge, gained through the exploration, mining, and development process, to the ongoing success of exploration programs. To emphasize this point, the basic geology of each of the major Rabbit Lake area deposits will be presented in chronological order of their discovery and subsequent development. These depos its include Rabbit Lake, Collins Bay A-zone, B-zone, D-zone and Eagle Point. The geological descriptions are based primarily upon the detailed observations of many current and former geologist s employed by both Gulf Minerals Canada Limited and Eldorado Resources Limited. Much of the early historical data was obtained from Dr. E.E.N. Smith, formerly with Eldorado Resources Limited. Regional GeologyThe Rabbit Lake area which includes the Rabbit Lake, Collins Bay A-zone, B-zone, D-zone and Eagle Point deposit s, is located on the eastern edge of the Athabasca Basin close to the western shores of Wollaston Lake (Fig. I). The area is in the Churchill Province of the Canadian Shield within the Wollaston lithostructural domain, at the eastern edge of the Athabasca Group. The uranium deposits occur within both the Wollaston Group metasedimentary assemblage of probable early Aphebian age, and the diagenetic ally altered quartz sandstones and conglomerates of the Athabasca Group of Paleohelikian age. Both units unconformably overlie granitoid gneisses interlayered with metasediments and a graphitic iron formation all believed to be of Archean age. All uranium depo sits in the Rabbit Lake area occur in close proximity to the Paleohelikian - Aphebian or Paleohelikian - Archean unconformity."

Jan 1, 1989

By Balmer Neilly

FOR some reason or other, Mine Taxation has never been a popular subject for discussion in meetings of this kind, and it has never received the study and consideration its importance demanded. By way of explanation, two reasons may be suggested. In the first place, the computation, adjustment, and final payment of taxes, have been looked upon in most cases as a Head Office chore. Secondly, since taxes represent an uncontrollable cost item, they have been treated as an added rather than an inclusive factor in calculating unit costs. Perhaps because I am half Irish, and therefore resent taxation of all kinds, perhaps because I am half Scotch, and am therefore concerned with the results, I have always taken a keen interest in this subject. Moreover, by some peculiar set of circumstances, I have been a participating party in many, perhaps I can say most, of the discussions on this subject that have taken place between the Governments and the representatives of this industry during the past thirty years. Looking backward, certain very definite impressions remain. Political considerations have never had any part in these discussions. Views have been exchanged upon the frankest possible basis, and, when we disagreed on some particular detail, we agreed to disagree, and followed through in harmony and? good faith. We, as an industry, have refrained from importuning and fault finding in ways that might be considered as petty or selfish, and it is only upon occasions such as this, where conditions necessitate action, that we lay our troubles before the powers that be. The Ontario Mining Tax Act was drafted by men who were earnest and practical as to purpose, and that Act has stood the test of time. It is, in. truth, a mode! Act, for it has been copied in its general clauses by both Quebec and the Dominion of Canada. We all know that, when a machine is running smoothly, we should leave it alone. The same is true of a well designed, easily applicable, taxation measure, and our present difficulty with respect to this Act arises out of an amendment made in 1916. In that year, you will remember, the Dominion imposed a wartime Income Tax Act. It was described as a wartime necessity and it was intimated t:1 at with the end of hostilities its application would be restricted and finally cancelled. The rate of taxation was modest, and when the Ontario Government was asked that the Dominion Income Tax be allowed as a deductible item, they readily acquiesced. This was looked upon as a temporary arrangement.

Jan 1, 1943

By E. Fiset, T. Hennebel, F. Verbruggen, A. Prévoteau, K. Rabaey

Arsenic (As), bismuth (Bi) and antimony (Sb) are known to affect the quality of copper deposits in copper electrowinning operations. The codeposition of As was previously believed to occur only at current densities far exceeding the range of typical current densities for copper electrowinning. In this study, we investigate the copper electrodeposition on different pretreated stainless steel (SS) substrates from bleed electrolyte in galvanostatic mode at –45 mA/cm². Scanning electron microscopy (SEM) micrographs illustrate that during the initial phases of copper nucleation and growth, the current density was locally increased due to the pretreatments. It was reasoned that the codepostion of As could possibly occur in normal electrowinning conditions, but the risk can be substantially reduced by good SS substrate handling and maintenance practices. INTRODUCTION The presence of As, Bi and Sb is known to have a deleterious effect on the copper cathode quality in copper electrowinnings (Hiskey & Maeda, 2003; Hoffmann, 2004; Xiao, Cao, Shen, & Volinsky, 2012; Xiao, Cao, Mao, Shen, & Ren, 2014; Jafari et al., 2017). They are known to influence both the chemical and physical quality of the copper as they can contaminate the copper (Jafari et al., 2017) and affect the copper deposit structure (Hiskey & Maeda, 2003; Kim, Kim, & Chung, 2009), which contributes to a degraded market value of the copper (Tuddenham, 1984). The incorporation mechanisms of these impurities are believed to occur mainly through slime inclusion (F. Xiao et al, 2012) and electrolyte inclusion (Hiskey & Maeda, 2003). Other studies suggested that codeposition of these impurities is possible by their standard reduction potential being close to the one of copper (Xiao et al, 2014). Hiskey and Maeda (2003) investigated the copper electrodeposition on a copper electrode substrate in Cu electrolytes with a Cu, H2SO4, As, Bi, Sb composition representative for commercial copper tankhouses. The combination of voltammographic techniques and Auger electron spectroscopy showed that As was the first impurity to be electrodeposited from this electrolyte, yet at potentials where the limiting current density of the copper electrodeposition reaction is exceeded. The copper tankhouses usually operate at a current density ratio of 0.3 to the limiting current density in order to achieve tolerable copper quality deposits. The codeposition of As could be considered impossible in this current density condition. However, it is known that during the initial phases of electrodeposition on foreign substrates, a substantial part of the reaction proceeds by growth of individual nuclei where the current density is locally high and diffusion limited (Radisic, Ross, & Searson, 2006). Furthermore, it was observed that copper nucleation on TiO substrates occurred preferentially in the scratched oxide free areas which could serve as parts with high localized current densities (Chang, Choe, & Lee, 2005).

Jan 1, 2019

By Leonard Kellogg

Introduction The Mine Manager or Superintendent is a man faced with a difficult problem. He must direct the activities of his mine in such a manner that, over a period of time, the greatest possible profit will be realized. In this respect, a mine is no different from any other business organized for profit. What makes the mine manager's task so difficult then? The profit of a mine is determined by -among other things -the grade of ore, the market price of the metal or metals produced, and the cost to operate the mine. The mine manager cannot do much about the first two of these, but he has considerable control over the operating cost. This cost will depend in large measure on the nature of the programme on which he plans to operate his mine. This operating plan may be broad or specific, on a long-range basis or on a month to month basis. The development of the plan, however, is made very difficult by the existence of so many factors which must be considered. These may be (1) factors requiring decisions based on the best judgment and interpretation of engineering and geological information available, or (2) items which must be considered but which are largely non-controllable. To be more specific, examples of such items would be: (1).-(a) The amount and type of development work to be done in relation to amount of ore to be mined. (b) Mining methods to be followed and type of equipment to be used. © Amount of exploration diamond drilling to be done if the orebody is not clearly defined. (2).-(a) Rock type and degree of hardness. (b) Width, depth, and pitch of veins. © Amount of work requiring timbering. (d) Faults encountered. (e) Water and gas conditions met with.

Jan 1, 1952

By Y. N. Zhang

Friction Stir Welding (F SW) is a novel "green" manufacturing technique due to its energy efficiency and environmental friendliness. This solid-state joining process involves a rotating tool consisting of a shoulder and/or a probe. The shoulder applies a downward pressure to the work-piece surface, constrains the plasticized material around the probe, generates heat through the friction and causes plastic deformation in a relatively thin layer under the bottom surface of the shoulder. The rotating probe mainly drags along, plasticizes, and mixes the adjacent material in the stir zone, creating a joint without fusion. Friction Stir Processing (FSP), a variant of FSW, has been developed to manufacture composites, locally eliminate casting defects, refine microstructure and/or improve the associated mechanical and physical properties including strength, ductility, fatigue, creep, formability and corrosion resistance. However, major challenges such as tool design and wear currently limit the use of F SW/P for manufacturing applications, particularly for high melting temperature or high strength alloys. In this review, the FSW/P tools are briefly summarized in terms of the tool types, shapes, dimensions, materials and wear behaviors.

Jan 1, 2011

By T. T. Wang, T. H. Huang, S. S. Zhan

"Fractures with diverse features dominate the hydraulic behavior of fractured rocks and are one of the major subjects for hydrogeological characterization of a site. This study investigates curve patterns obtained by packed tests, and as well the influence of fracture features based on 59 sets of in situ packer tests with different fracture combinations and fracture features. The result shows that, in the example of Heshe site, neat and tidy fractures usually provide stable channel for water flow during testing, and the hydraulic properties of fractures infilled with breccia and mud may change during testing because of leaching and/or washed out of infilling breccia and mud. Different combinations of fractures with diverse features in packed test sections lead to different curve patterns for in situ hydrogeological tests. For groundwater flowing predominately through neat and tidy fractures, the pressure-discharge curve of modified Lugeon tests are usually linear curve pattern, and the pressure decrease while the discharge increase in pressure-discharge-time curves of single-hole double packer tests, which benefit statistically determining the transmissivity of dominant fracture sets. INTRODUCTIONFractures interlaced in rock masses are major channels for groundwater flow and generally account for the anisotropic and heterogeneous characteristics of permeability for fracture rocks. To describe reasonably the permeability of a fracture rock, the Discrete Fracture Network (DFN) approach and others with similar ideals have been developed. Many methodologies and associate equipment, for instance, the televiewer and the in situ hydrogeological test, have been proposed to investigate the spatial distribution and the transmissivity for different fracture sets, which are two main parameters necessary for the DFN or similar model simulation (Pearson & Money, 1977; Barker & Black, 1983; Hsieh et al., 1985; Bernard et al., 2006; Quinn et al., 2012). However, diverse outlooks for the pressure-discharge curves and the temporal pressure and associate temporal discharge curves often confuse the investigation results by significant deviations on derived permeability (Houlsby, 1976; Zlotnik, 1994; Royle, 2009; Camilo, 2010).Aiming on technical development for in situ hydrogeological tests and fracture investigation, an experimental well site with 10 wells has been established in Heshe in central Taiwan since 2011 (Wang et al., 2011; Song, 2012; Zhan et al., 2013). Extensive geological survey and well-hole scanning by a televiewer provide spatial distributions and outlooks of fractures in detail. Additionally, a series of Lugeon tests, double packer injection tests and pumping tests have been performed to investigate the permeability of fracture rocks, and dominate fracture sets as well. Based on the results obtained from the Heshe site, this study classifies the curve patterns of hydraulic packer tests. The features of fractures involved in packed sections for packer tests are then inspected in detail. Relationship between the curve patterns of hydraulic packer tests and associated features of corresponding fractures in rock are discussed and addressed accordingly."

Jan 1, 2015

By W. K. Muwais, R. G. Cuddy

"The Lower Cretaceous McMurray Formation contains the bitumen reserves of the Syncrude Mine in northeastern Alberta. This formation comprises sediments deposited sequentially in fluvial, estuarine and marine depositional environments. The Syncrude Base Mine area consists mostly of estuarine sediments, as much of the original marine sediments have been eroded away. These estuarine deposits consist of channel-fill sediments and interchannel tidal flat sediments with the channel-fills comprising most of the orebody.Channel-fills contain, among other lithologies, interbedded sand, silt and clay rich layers that often occur as sequences of inclined beds with dips up to 25 degrees or more. A detailed knowledge of the distribution of these inclined beds, their lithological characteristics and their continuity is very important in assessing the risk of mine highwall instability . Techniques used to identify and characterize adverse structures are reviewed. INTRODUCTIONGeneralThe Syncrude Canada Ltd. oil sand mine is located within the surface mineable portion of the Athabasca Oil Sands area about 40 kilometres north of Fort McMurray in northeastern Alberta, Canada (Fig. I). The company commenced large-scale strip mining of oil sands in June 1977in the area, referred to as the Base Mine, situated in the southeast corner of the company's two lease areas (Fig. 2).The mining method (Fig. 3) utilizes large electric drag lines operating on a single bench with highwall depths up to 60 metres. Feed grade oil sand (= 6 wt.% bitumen) is mined by draglines and windrowed parallel to the highwall crest. Lower grade oil sand « 6 wt. 0J0 bitumen) occurring as waste bands is selectively mined by the draglines and cast back into the mined out pit or placed on the bench and hauled by truck. The windrowed feed is delivered to the extraction plant by a bucket wheel reclaimer and conveyor system. Stripping of Recent, Pleistocene and Cretaceous overburden units is done outside the conveyor systems by mobile equipment. The 4.5 kilometre long mine is split into four quadrants for planning and scheduling purposes, with each quadrant having an individual dragline-bucketwheel-conveyor system.Surface mining of oil sand at Syncrude requires the removal of vast quantites of material. The design of the open pit mine relies heavily on knowledge of the distribution of ore and waste materials, and on the physical characteristics of these materials.The geology of the oil sand below the dragline bench at the Syncrude Mine is complex. Geological, geotechnical and hydrogeological factors play an important role in the design and operation of the mine. This paper describes aspects of the geology that impact on the design and operation of the mine. Some of the methods and procedures adopted by Syncrude to successfully overcome difficulties that the complex geology creates are discussed."

Jan 1, 1989

By G. W. Govier

Measurements of the settling rates and the rheological behaviour of heavy media formed of fine suspensions in water of each of magnetite, ferrosilicon, and galena have been made. For media ranging from 1.6 to 2.8 specific gravity the settling measurements gave initial settling rates of from 0.5 to 0.01 ?cm. 'Per minute for magnetite; from 4.0 to 0.8 cm. per minute for galena; and from 35 to 1.6 cm. 'Per minute for ferrosilicon. These measurements indicate the ?relative stability of the suspensions and should be helpful in establishing the useful specific gravity range for each medium. Measurements of the consistency of the media were made with a Fann Model 35 rotational viscometer. Aibnormal or non-Newtonian behaviour was observed in the case of each media, the apparent viscosity being dependent upon the rate of shear or the intensity of motion. Measurements were made over the rate of shear range of 10? to 1,000 reciprocal seconds. The apparent viscosities of the magnetite media ranged from 450 down to 4?0 centipoise at 2.30 specific gravity, and from 2,450 down to 700 centipoise at 2.80 specific gravity. In the case of the galena media, the variation was from 40, through a minimum of 6, to 10 centipoise at 2.20 specific gravity, and from 950, through a minimum of 180, to 450 centipoise at 3.6 specific gravity. The ferrosilicon suspensions exhibited apparent viscosities ranging from 42, through a minimum of 5.6, to 9 centipoise at 1.9 specific gravity, and from 160, though a minimum of 35, to 85 centipoise at 2.8 specific gravity. The dependency of apparent viscosity or consistency upon intensity of motion is considered to be of particular significance in applications of heavy media where the medium is in rapid motion.

Jan 1, 1957

By D. J. W. Piper, T. Hundert, G. Pe-Piper

"Abstract - Potentially commercial deposits of kaolin are found in the fluvial Lower Cretaceous Chaswood Formation, the sedimentologically proximal equivalent of deltaic sediments of the offshore Scotian basin. The geological setting of the kaolin deposits has been interpreted from high-resolution seismic-reflection profiles and boreholes, and mineralogical studies on one reference borehole. The kaolin is a product of early diagenesis involving meteoric water below the water table. The distribution of kaolin is controlled by the presence of intraformational unconformities that were sites of ground water recharge, and are marked by the development of oxisols above the water table. Such diagenesis was facilitated by interbedded, loosely consolidated, permeable sandstone. The highest-grade kaolin deposits are found in areas close to river belts, where overbank muds were not sufficiently drained to develop paleosols, but where later uplift created intraformational unconformities. In the sandstone, meteoric water flow altered feldspars to kaolin, thus yielding commercial silica sand deposits. It also altered ilmenite to rutile, which is concentrated as secondary placers in modern rivers that have eroded the Chaswood Formation and tills derived therefrom. Sommaire - Des dépôts de kaolin potentiellement économiques ont été notés dans la Formation de Chaswood d'’âge Crétacé Inférieur, laquelle constitue un équivalent latéral en milieu fluviatile aux sédiments deltaïques du bassin de Scotian. Le contexte géologique de ces dépôts de kaolin a été interprété a partir de profils de seismique-réflection à haute résolution, de sondages, et d’études minéralogiques sur un sondage de référence. Ce kaolin est un produit diagénétique précoce formé par de l’eau météorique sous le niveau de la nappe phréatique. La distribution du kaolin est contrôlée par la présence de zones de recharge associées à des discordances intraformationelles marquées par le développement d’oxisols au-dessus du niveau de la nappe phréatique. La présence d’interlits de grès perméables faiblement consolidés a contribué à l’efficacité de ce processus diagénétique. Les dépôts de kaolin les plus riches se trouvent en périphérie des rivières, là ou les boues de la plaine d’inondation n’étaient pas suffisamment bien drainées pour permettre le développement de paléosols, mais où des mouvements verticaux subséquents ont crée des discordances intraformationelles. La circulation d’eau météorique dans les grès a entraîné l’altération des feldspaths en kaolin, générant ainsi des dépôts économiques de sable de silice. Elle a aussi causé l’altération de l’ilménite en rutile, que l’on trouve dans des placers secondaires situés dans des rivières contemporaines qui ont érodé la Formation de Chaswood et les tills qui en sont dérivés."

Jan 1, 2006