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By Kristine Haug

Although most in situ operations in Alberta do not encounter significant problems during resource extraction, there have been a few documented occurrences of oil or steam releases as a result of compromised caprock seals. The objective of the Oil Sands Caprock Integrity Project (OSCRIP) is to characterize the units above and below bitumen zones to determine which geological factors affect the quality of the caprock seal. In addition, geomechanical properties and stress measurements of the bitumen reservoir and overlying units will be examined to provide a better picture of the containment conditions in which in situ operations occur. The information from this study will aid regulatory staff and industry in determining the zone-specific geological and geomechanical factors that could affect the design, operation, and feasibility of in situ recovery projects. The OSCRIP study area (Townships 87 to 99 and Ranges 1 to 13, West 4th Meridian) encompasses the surface mineable area, the northeast extent of the Wabiskaw-McMurray bitumen deposit and the Clearwater Formation, as well as a wide band of the Devonian salt-dissolution zone. Regional geological mapping of the Cretaceous strata focuses on the spatial extent and thickness of the caprock seal. Mapping of the underlying Devonian strata is targeted at better understanding the potential effects of salt dissolution and collapse of overlying strata on the integrity of the caprock seal. Examination of LiDAR (Light Detection And Ranging) bare earth DEM in the study area has revealed localized depressions that may represent sinkholes rooted in subsurface collapse features in Devonian carbonate and evaporite strata. Mapping the location and understanding the timing of salt dissolution-related features and deformation in the Devonian strata will help address questions about the possible effect that geological structures, such as sinkholes, have on the integrity of the caprock, as well as the potential for localized variations in the stress regime of the bitumen zone and overlying units. The stress regime in units above 350 m is such that any induced fractures are believed to be horizontal, and therefore, there would appear to be no mechanisms that would allow these fractures to reach the surface. However, recent incidents have shown that vertical pathways can occur, linking the subsurface to the surface. The final phase of the project will evaluate the changes that may occur in the stress regime under thermal operating conditions in the study area.

Jun 1, 2012

By H. R. Huffman

"This paper reviews the history of iron powder production, and outlines the varions production methods. The uses of iron powder and the reasons for its use are also covered. The paper concludes with a look at future trends in powder metallurgy.INTRODUCTION TO POWDERSTHE IRON POWDER INDUSTRY is enjoying a very rapid growth. The annual consumption of iron powder is now at the 100,000-ton level, twenty times higher than it was at the end of World War II, and the yearly in-crease bas been almost consistent at 20 per cent. This is expected to increase, bringing the tonnage to 200,-000, or even (according to some experts) to 270,000, in 1970. In any event, powder metallurgy is expanding at high speed and making an important impact on the production of iron and steel products. Some indication of the faith in the future market may be indicated by the commencement of three new powder production plants in Canada with a total capacity of 136,000 tons annually."

Jan 1, 1969

By David C. Mulder

As a result of the dramatic growth of Edmonton, Alberta during the past decade and the rapidly increasing price of natural gas, Edmonton Power has received provincial government approval to construct and operate an 8O0-megawatt- capacity coal-fired thermal generating station at Genesee, about 50 km southwest of Edmonton. The power plant will consist of two 400-megawatt steam-driven thermal generators, with provision in the future for two or more additional units. The coal will be hauled by truck from the nearby three-million-tonnes- per-year strip mine, with economically recoverable reserves exceeding two hundred million tonnes. Edmonton Power controls a major part of the coal leases in the area, and is working with other lease holders in developing the most efficient mining plan. A natural depression was selected as the site for the 600-hectare cooling pond to provide water for the power plant. Edmonton Power is working closely with the people in the area to ensure that their rights and concerns are communicated and recognized by all parties.

Jan 1, 1981

By Tomoya Kawasaki, Tatsuya Motomura, Yutaka Yasuda

Saganoseki Smelter, one of the largest copper producers in Japan, currently operates a single flash smelting furnace to produce 450,000 tons of new copper annually. The smelter used to employ two flash furnaces, and integrated the two into one in 1996. Since then, various improvements to its facilities and technologies have been made to increase productivity. To upgrade the operation efficiency, "stability" was considered a key issue, and the measures were taken to increase the operation and facility reliability. Currently, the furnace is running at a feed rate of 215 DMT/h, while the furnace utilization has been maintained at 97%. This paper outlines recent improvements that have made to increase furnace productivity and efficiency.

Jan 1, 2014

By K. E. Harley, M. J. Whiting, T. J. Sabin, E. M. Ryan, J. F. Watts

"Wire and Arc Additive Manufacturing (WAAM) has the potential to enable a very significant reduction in buy-to-fly ratio compared to conventional manufacturing through the ability to build near-net shape components. Components manufactured from AA 2319 by WAAM can exhibit significant levels of porosity. There is also a variation in the physical appearance of the surface deposit sometimes found on such components. This deposit is similar to those observed on aluminium joined by MIG and TIG welding processes. It has been suggested that both the bulk porosity and the surface deposit are caused by hydrocarbon-based lubricant on the feedstock wire. An established correlation between surface deposit and porosity would offer valuable insight into WAAM products and enable early interventions in quality control or process monitoring based on visual examination. The relationship between the nature of the surface deposit and porosity has been studied for AA 2319 WAAM components manufactured using different wire batches. Evidence is presented to support the assertion that (i) there does not appear to be a relationship between surface deposit coverage and porosity, (ii) batch-to-batch variability in feedstock wire affects porosity. This study has led to a better understanding of the cause of porosity in WAAM components.INTRODUCTION There is a high cost associated with conventional, subtractive manufacturing because of the high ‘buy-to-fly’ ratio, a measure of the initial material bought compared to the material found in the finished part (Allen, 2006; Yilmaz & Ulga, 2016). A typical aerospace product may have up to 90% of the purchased billet of forging machined away which is cost inefficient and high in material waste. Wire and Arc Additive Manufacturing (WAAM) has the potential to reduce costs and lead time. Robotically controlled weld torches rapidly deposit feedstock wire in layers to build large near-net shapes with mechanical properties similar to those of conventional manufactured parts (Sequeira Almedia & Williams, 2010; Martina et al., 2012; Ding et al., 2015; Williams et al., 2015). A high level of porosity variation has been observed in aluminium WAAM parts (Cong, Ding & Williams, 2014; Gu et al, 2016) which can result in a range of material properties (Rudy & Rupert, 1970). This leads to difficulties in regards to standardisation and qualification of process and parts. In order for WAAM to be used commercially, porosity will need to be understood, monitored and reduced to a reproducible acceptable level or eliminated."

Jan 1, 2018

By M. Pötsch, A. Kluckner, P. Söllner, W. Schubert

"The in situ block size is a key parameter in the geomechanical characterization of rock masses. It describes the fracturing of the rock mass and thus is a measure for the degradation of the rock mass strength. Several classification systems use the in situ block size. For instance, the Geological Strength Index (GSI) requires the “blockiness” and joint surface condition factor as key input parameters. The “blockiness” has recently been related to the in situ block volume (Cai et al., 2004). Due to the limited information about the internals of a rock mass, it is not possible to determine the in situ block size directly. Currently, the in situ block size is determined by calculations using oversimplified models, vague estimations or, due to the lack of relevant information, it is neglected. As remote measurement systems have become available for rock mass characterization, a more comprehensive record of discontinuities can take place. Measurements can be performed on exposed rock outcrops and in particular on tunnel faces and walls, delivering the location, orientation, spacing and persistence of discontinuities at an arbitrary number and locations. An estimation of the in situ block size at the same level of sophistication is still not available. This paper aims at examining the relationship between visible and measureable information at the rock surface, and the in situ block size. Three-dimensional block model simulations were performed using the block model engine of the distinct element code 3DEC. Initial investigations focussed on the minimally required observation area in order to obtain reliable block size distributions. Based on a representative volume element, a reference distribution of the block area at the observation area for a specific discontinuity system was determined. Subsequently, the size of the observation area was decreased stepwise and each new distribution was compared to the reference distribution. For all analyzed systems, it turned out that the mean block area must be smaller than 1% of the observation area to achieve a reliable block size distribution. Further simulations focussed on discontinuity systems with three non-persistent sets. The results were compared to the formula proposed by Cai et al. (2004). A transformation factor T was introduced which replaces the persistence terms in Cai et al.’s proposed formula. The factor describes the correlation between block volumes generated by persistent and corresponding non-persistent discontinuity sets. The simulations included the variation of the discontinuity set spacing, persistence, and orientation. The mean and additionally the 25%-, 50%- and 75%-quantiles of the block size distribution were analyzed. Examining all values for the transformation factor the distribution can be described by a power function with a negative exponent. The function depends on the persistence only. Finally, the results of random simulations were compared to the analytical formula using the transformation factor. The predicted mean and selected quantiles show a good agreement with the simulation results. It gives a comprehensive picture about the block size distribution in discontinuity systems with three non-persistent sets."

Jan 1, 2015

By K. Woo

"With ever-increasing global demand for mineral resources, mining companies are considering developing deeper, more complex and lower grade ore bodies. Recent years have seen the transition from surface to underground mass mining operations to access deeper resources, with mass mining methods such as block and panel caving being favoured due to the tonnages and economics achievable when dealing with lower grade ore. However, the rock engineering interactions involved with such plans are complex and challenging given the significant disturbance caused to the surface environment. If not properly accounted for, the unexpected propagation of a cave breaking through to surface or the differential surface displacements otherwise produced may threaten the safety and integrity of overlying mine and civil infrastructure.This paper reports the findings of a comprehensive research programme focussed on investigating and integrating new developments in remote sensing characterization and monitoring technologies with state-of-the-art numerical modelling to better manage the challenges and geo-risk associated with the transitioning from open pit to underground mass mining. Procedures were developed to integrate discrete fracture networks (DFN) into finite-element/discrete-element analyses to simulate the influence of rock mass fabric on cave propagation and the evolution of caving-induced surface subsidence and step-path failure of large open pit slopes through the progressive failure of rock bridges. The results clearly showed that caving-induced surface deformations tend to be discontinuous and asymmetric due to large movements around the cave controlled by geologic structures, rock mass heterogeneity and topographic effects. Although parallel investigations of empirical design charts used to predict caving-induced deformations were found to be moderately sufficient for assessing the extent of macro deformations directly above the undercut (i.e. caving collapse features), numerical modelling was found to provide the only means to confidently estimate the lateral extent of smaller strain subsidence.These results were further supported by the use of high-resolution synthetic aperture radar (SAR) data to monitor the ground deformations associated with block caving production, and to use these to calibrate and constrain a series of predictive 3-D numerical models focussed on Rio Tinto's Palabora mine in South Africa. The InSAR data was obtained from Canada’s recently launched RADARSAT-2. The close fit achieved between the predictive 3-D numerical model and InSAR monitoring data demonstrates the significant value of InSAR calibrated 3-D numerical models applied to subsidence prediction.Collectively, the results from this research programme have helped to further the characterization, assessment and understanding of mass mining-induced subsidence, and its evolution, by addressing existing limitations in the use of empirical and numerical design methods. The limitations and uncertainty arising from mine site data were detailed, specifically the representation of mine geology, rock mass properties, in-situ stresses and cave propagation, together with means to constrain these inputs and calibrate sophisticated 3-D numerical models through back analysis and integration with high resolution monitoring data."

Jan 1, 2015

By Arnold R. Miller

Overview ? Vehicle Projects LLC (prime contractor) and the Fuelcell Propulsion Institute have developed the world?s first fuelcell locomotive. ? Principal applications are underground mining and tunneling. ? Because fuelcell vehicles solve the problem of underground emissions, mining is expected to be their first commercially viable market. ? The first year of a three-year project to develop a fuelcell mine loader is funded and underway.

May 1, 2002

By A. Zangooi, J. A. Finch

"A frother analysis technique based on the formation of a colored solution with UV-VIS absorbance proportional to frother concentration over a certain range has been developed. The calculation of concentration requires the comparison of the sample absorbance at a selected wavelength with a linear calibration (frother concentration vs. absorbance) constructed with values collected from solutions of known concentration (standards) at the same wavelength. It has been found that concentration ranges for preparation of standards can vary widely. An integration of our experiences into a databank can offer some guidance on the selection of standard concentrations. The databank includes results from the analysis of 37 chemical reagents, commercial frothers, and natural oils used in research work or at industrial sites. Grouping frothers by similar chemical structure or origin provides a good basis for selecting the standards to approach the maximum absorbance range for the spectrophotometer in use.INTRODUCTIONA technique to determine frother concentration on samples of industrial milling streams based on formation of a colored solution with UV-VIS absorbance proportional to frother concentration has been developed. The concentration is determined by comparison of its absorbance, at some selected wavelength, with those obtained by processing a series of solutions of known concentration (standards), at the same wavelength. It is desirable to have linear calibration (frother concentration vs. absorbance) over the widest concentration range. The upper concentration can be restricted by the instrument, as there is a maximum detectable absorbance (minimum transmittance), which can be reliably sensed by the UV-VIS detector (in most cases maximum absorbance is 3)."

Jan 1, 2016

By Jae-Chun Lee, Sadia Ilyas

We investigate the technical feasibility of bioleaching of metals from low grade sulphidic ore. Experiments were conducted with an adapted consortium of Sulfobacillus thermosulfidooxidans and Thermoplasm acidophilum in batch bioreactors (1.5 L), small columns (10 kg ore load, 8 % S0 sludge) and large columns (80 kg ore load, 12 % S0 sludge). Approximately 83 % Ni, 85 % Cu, 55 % Fe and 81 % Zn was leached out in batch mode while 93 % Ni, 89 % Zn, 81 % Cu and 65 % Fe was leached out in column reactors. Bioleaching potential improved by acid pre-leaching, adaptation of microbial consortium and periodic bleeding of effluents.

Jan 1, 2014

By K. Robertson, K. A. Scalise, K. C. Kocsis, M. B. Teixeira

"Many deep and highly mechanized underground metal mines require cooling. In many cases, appropriate working conditions might be fulfilled by ventilation alone, but some require the implementation of cooling systems. The most common cooling systems are bulk air cooling and localized cooling. These systems are effective, but they use considerable amounts of electricity. Ground source heat pumps (GSHP) can supplement existing cooling and heating systems, while geothermal systems can cool the mines in their entirety if there are significant sources of geothermal energy are present. A major advantage of geothermal and GSHP systems are their renewability, which reduces the carbon footprint of the mine.INTRODUCTIONThe western United States has abundant alternative energy sources including a high potential for geothermal energy. Geothermal utilization is a viable energy alternative that many areas throughout the world have access to because high geothermal potentials are located near areas of volcanic activity such as along plate boundaries, mid-oceanic ridges, rift valleys and hot spots (IRENA, 2017). There is significant potential to use geothermal energy for many applications. With constantly evolving and innovative technologies being developed, an increasing number of geothermal applications are becoming feasible. The western United States is an ideal candidate for alternative energy applications due to the geothermal availability and the emergence of modern technology. This paper investigates the incorporation of renewable methods and the alternative energy possibilities of Barrick Goldstrike, located in northern Eureka County, NV and Rio Tinto/BHP Billiton’s Resolution Copper mine located in Superior, AZ.RENEWABLE SYSTEMSGeothermal SystemsGeothermal temperatures are typically defined as either high or low temperature systems(Shengjun, Huaixian, & Tao, 2011). The high-temperature reservoirs (>220°C / 428°F) are feasible forlarge, commercial production of electricity with dry stream and flash stream systems (Shengjun, Huaixian, & Tao, 2011). Low temperature systems, below 220°C (428°F) (Shengjun, Huaixian, & Tao, 2011), aremuch more difficult to use for energy production. Low-temperature reservoir heat can be harnessedthrough the implementation of a binary cycle plant. The working fluid for a binary cycle plant is eitherorganic (Organic Rankine Cycle (ORC)) or an ammonia-water mixture (Kalina cycle). Organic fluids andammonia-water mixtures have low boiling points that allow for the recovery of heat from low-temperaturesources (Eymel Campos Rodriguez, et al., 2013). The efficiency of the binary cycle plant varies depending upon the fluid, thus the proper selection of the fluid is critical for maximum energy output"

Jan 1, 2019

By T. G. Phillips

"This paper gives an inside look at a bulk terminal and describes the preparations that must be made by a company in developing such a terminal and its position in today's traffic pattern. The following headings cover the subject material: (a) Traffic pressures, their detection and measurement, (b) position in the traffic flow -selection of site, (c) transportation connections -present and possible future routes, (d) engineering studies and costs, (e) contracts, the basic material for insured traffic, (f) financing, (g) budgetary control, (h) development of new techniques, (i) growth into new cargoes or cargo-handling methods and (j) consolidation."

Jan 1, 1968

By E. Stansfield

Coal samples are sometimes taken from a wet spot in a mine, or from an open car or pile shortly after rain, and submitted for analysis in a dripping wet condition. Other samples are taken from a dry spot in the mine, or from an open car or pile after a period of dry weather. Comparison of the analyses obtained in the two cases would be absurd, although the samples might be of essentially the same coat apart from the surface moisture on the one. The analyst therefore attempts to reduce all samples to an equal basis by the operation known as air-drying. Air-drying is practised by the chemist for three reasons: (1) To make it possible to grind the coal to powder. (2) To bring the coal sample to a condition in which it will not change in weight rapidly whilst portions are being weighed out for analysis -in other words, to bring it into equilibrium with the air in the laboratory. (3) To determine the water-retaining power of the coal. Any kind of drying is satisfactory for (1); the coal should be dried more or less according to the humidity at the time in the laboratory for (2); whilst it should be always dried to the same extent for (3). In other words, no method can be satisfactory for both (2) and (3). In this paper the only question considered is (3) -that is, air-drying the coal under standard conditions so that strictly comparable results can be obtained for the water content of coals after air-drying. After a sample of wet coal is exposed, it loses moisture until it is in equilibrium with the air at the time: thus the coal will loose distinctly more water in air of 20 per cent relative humidity, for example, than it would in air of 80 per cent.

Jan 1, 1923

By Seher Ata

"Virtual reality, a three-dimensional computer generated environment, has become recognized delivery system for many forms of education. This article describes the application of virtual reality to mineral processing education. An interactive mineral processing visualisation module has been developed at University of New South Wales (UNSW), Australia. The module provides students with an overview of a base metal concentrator, details about each stage of the process, as well as revealing how the mined ore progresses from stage to stage. The module also involves developing a number of instructional based plant layouts and flowsheets in the virtual environment that are intended to assist the user in understanding the essential components of the base metal concentrator.INTRODUCTIONVirtual Reality (VR) is the creation of an artificial environment that is experienced through sights and sounds provided by a computer (Squelch, 2001). The simulated environment is achieved through a host of technologies such as three-dimensional graphics, audio feedback and special peripheral devices to produce interactive environments.VR has been used in diverse fields including medicine (Riener & Harders, 2012), entertainment (Hsu, 2011), military (Manojlovich, Prasithsangaree, Hughes, Chen, & Lewis, 2003), manufacturing (Zimmermann, 2008; Jiang, 2011), and chemical processing (Schofield, Lester, & Wilson 2005; Squires, Andersen, Reklaitis, Jayakumar, & Carmichael, 2014). VR is also becoming recognized delivery system for many forms of education, including engineering education (Bell & Fogler, 1996; Bell & Scott, 1998; Shin, 2002). For example, virtual laboratories have been designed and developed to teach students fundemental features of the heterogeneous catalytic mechanisms and absorption columns (Bell & Fogler, 1995), the multi-phase and multi-component blast furnace iron making process (Babich & Senk, 2009) and to guide students to identify various safety measures while working in real laboratory (Bell & Fogler, 1996)."

Jan 1, 2016

By M. P. Amsden

"Ecstall Mining Limited, a subsidiary of Texasgulf, Inc., Operates the Kidd Creek Mine, Concentrator and Zinc Plant at Timmins, Ontario. Two different ore types are mined and milled to produce concentrates of copper, zinc, lead and tin. The ores are processed at the Concentrator in three separate individual milling circuits, each with the capacity to treat up to 3500 tons per day. Two circuits treat copper-zinc ore 1t an average combined rate of 6500 tons per day and the third circuit treats 3500 tons per day of silver-lead zinc ore. Conventional crushing, grinding and flotation procedures are followed. The purpose of this paper is to describe Ecstall's experience with rubber mill linings in the grinding circuits.CrushingBoth ores are crushed to minus 6 inches at the Mine and delivered by rail to the Concentrator where they are reduced by secondary and tertiary crushing to minus 5/8 inch.GrindingThe crushed ores are prepared for selective flotation by grinding with rod mills and two stages of ball milling. flotation circuit middling products are reground in regrind mills prior to further treatment. A typical flowsheet of one of the grinding circuits is shown in Figure 1.All the grinding units are Allis-Chalmers Mills. The rod mills are 10 1/2 feet diameter by 16 feet long. Both the primary and secondary ball mills are 12 feet diameter by 18 feet long and all regrind mills are 6 feet diameter by 12 feet long. The primary mills are charged with 1 13/16 inch forged balls. Secondary mills are charged with 1 1/2 inch forged balls and the regrind mills are charged with 1 inch forged balls. All cyclones are Kreb units. The primary cyclones are Dl5B hydrocyclones, the secondary cyclones are D6B hydrocyclones and all regrind cyclones are D6B hydrocyclones."

Jan 1, 1974

By E. McLaren, J. Sanftenberg, C. Cameron, H. Dello Sbarba

"A Ventilation on Demand (VOD) system has been optimized and maintained at Glencore’s Nickel Rim South Mine (NRS) in Sudbury, Ontario, Canada for the past seven years. The system monitors and controls air quality and quantity through real-time, dynamic automation of primary fans, secondary fans, automated airflow regulators, and air monitoring instrumentation with VentSim™ CONTROL, a VOD software. This paper will focus on the implementation of testing procedures and system maintenance methods. Overall, the results show a consistent reduction in energy usage.INTRODUCTIONThe Ventilation on Demand (VOD) system at Glencore’s Nickel Rim South (NRS) mine in Sudbury, Ontario, Canada, involves the control of two 2,980 kW centrifugal surface exhaust fans with Variable Frequency Drives (VFDs), three 335 kW vane-axial surface intake fans with VFDs, 21 automated airflow regulators, six automated dampers, seven automatic doors and 198 underground auxiliary fans with ON/OFF starters. Additionally, the system monitors airflow at 48 locations, carbon monoxide (CO) at 40 locations, nitrogen dioxide (NO2) at 21 locations, and dry bulb and wet bulb temperature at 21 locations. The VOD system is also integrated with a tagging and tracking system to modulate the ventilation system automatically and in real time according to the presence and position of the personnel and vehicles. The tracking system comprises of 75 vehicle tags with diesel status and hydraulic status (ON or OFF), 440 personnel tags, and 200 tracking zones. Finally, it also involves the configuration and updating of 55 level plan and interactive procedures and 24 daily scheduled events. NRS currently uses VentSim™ CONTROL, Ekahau Tracking and PI Datalink to control, monitor, and configure their VOD system."

Jan 1, 2019

By James Stenhouse

Abstract The aqueous oxidation of pyrite in caustic solutions under oxygen pressure was investigated by measuring that effect of reaction variable on oxygen consumption by the reactions. From the results of this investigation, a model for the process has been proposed. In this model, sulphur diffuses as a positive ion through an oxide layer which forms on the sulphide particles and is then oxidized to sulphate ion. Iron is oxidized by substitutional diffusion of oxygen atoms into the oxide layer. The effect of most reaction variables on the rate of oxygen consumption can be explained with this model. Introduction Recent investigations (1,2,3) have shown that certain sulphide ores can be readily leached by agitating the ore in the form of a pulp under pressure in the presence of oxygen. Since very little was known of the mechanism of this oxidation, a programme of investigation was inaugurated in 1949 in the laboratories of the Department of Mining and Metallurgy of the University of British Columbia. Financial support for the investigation was received from the National Research Council in the form of student grants and bursaries, from the Canadian Liquid Air Company, Limited, and from the Consolidated Mining and Smelting Company of Canada, Limited. The first objective was to devise a technique to study the primary oxidation reactions in aqueous solutions and to apply the technique to a detailed study of the oxidation of pyrite in caustic solutions.

Jan 1, 1952

By C. Liu

Corrosion behavior of the stir zone in a friction stir weld of dissimilar A12024/AZ31 alloys was investigated in the immersion test in distilled water (pH=6) for different times. Microstructures and the distribution of chemical elements were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Due to the difference in the corrosion potentials between A12024 and AZ31, the AZ31 alloy constituent in the stir zone was susceptible to the corrosion attack in the distilled water. The corrosion attack was found to occur in the narrow region of the AZ31 alloy adjoining the A12024 region, where there was a low ratio of anode-to-cathode surface area. The corrosion attack became more severe in the AZ31 alloy regions with increasing immersion time. The A12024 alloy region in the stir zone of the weld was protected by cathodic reactivity due to sacrificial anode AZ31 alloy.

Jan 1, 2007

By A. J. Hyett, R. D. Reichert

"A laboratory and field research program was conducted to investigate the major factors influencing bond capacity of grouted cable bolts. The results indicate that cable bolt capacity most critically depends on the grout uniaxial compressive strength (UCS), the radial confinement, and the embedment length.In the laboratory &apos;split-pipe&apos; tests were conducted using P VC, aluminum and steel pipes to provide radial confinement, and field test sites were chosen in granite, limestone and shale rock masses. For both datasets higher capacities were obtained under conditions of higher radial confinement. A correlation between the two was obtained through a comparison of the radial wall stiffness of the laboratory pipes with that of the field boreholes as measured using a high pressure dilatometer. Cable bolt capacity was found to increase with embedment length though not in direct proportionality.The use of low water cement ratio grouts (<0.40) can increase cable bolt capacities by 50% to 75%. This effect is maximized under conditions of high radial confinement. However, the use of super thick grout paste (0.30 and less) may be both impractical and undesirable, first because of their limited pumpability and second because of their inconsistency in strength. Grouts with a water cement ratio of between 0.35 and 0.40 are recommended for practical cable bolt applications."

Jan 1, 1992

By J. D. Bateman, A. S. Dadson

"The Giant claims are on the west side of Yellowknife bay about 1 ½ miles north of the settlement of Yellowknife. They were staked in 1935 by prospectors in the employ of Burwash Yellowknife Gold Mines, Limited, and were transferred to Giant Yellowknife Gold Mines, Limited, in 1937, on the incorporation of that Company. During the period 1936 to 1940 a number of surface discoveries were investigated by trenching, test pitting, and diamond drilling. A shallow inclined shaft was sunk on the Brock zone, a system of narrow and irregular quartz veins, and some 75 tons of high-grade ore was mined and shipped to the Trail smelter. In 1943 management control was acquired by Frobisher Exploration Company, Limited. An intensive campaign of diamond drilling was commenced in January 1944 and carried on continuously for 2 years. This drilling indicated the presence of substantial gold orebodies lying within well-developed shear zones. Two shafts, 1 ¼ miles apart, were sunk during 1946 and underground development started on two of the orebodies.The claims are underlain largely by rocks of the Yellowknife greenstone belt, which extends from the shore of Great Slave lake along the west side of Yell ow knife bay and northward . The most conspicuous structural features are the steeply dipping late faults. The chief of these is the West Bay, which bisects the greenstone belt at an acute angle and crosses the southern part of the Giant group. At the 'big bend' near the west boundary of the claims there is a remarkably sudden change in the strike of the fault, from about 12° N.W. to about 3° N.E. The apparent horizontal displacement along this fault is of the order of 3 miles, with the east side moved relatively north. There are also a large number of lesser faults with apparent horizontal displacements of a few feet up to l,70J feet for the Townsite fault. Most of these faults trend north to northwest. Surface examination indicates that, at least for most of them, the movement corresponds to that along the West Bay fault, that is, the east side moved relatively north. According to the available evidence, all or most•of the movem:nt along the West Bay fault and along the lesser faults was post-ore. Late diabase dyk:s that cut through ore-bearing shear zones, with chilled margins in contact with the mineralized material, are apparently displaced to the same extent as earlier geological markers. ( see Frontispiece. )"

Jan 1, 1954