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By D. W. Hayley

The rapid expansion of exploration drilling with anticipated production facilities for oil and gas in the Mackenzie Delta region of the Northwest Territories has created a demand for granular construction materials. This paper discusses the technique adopted and experience gained by the authors from several major resource evaluation programs in this remote area. The first part of the paper describes a methodology for deposit identification, logistics of helicopter and ground-based drilling operations and the sampling difficulties which are unique to permafrost: soils. The second part describes the exploitation of a large glaciofluvial deposit at YaYa Lake on Richards Island. Granular construction material is sparse in the delta region relative to projected demand. Exploitable sources of granular materials for aggregates or construction borrow are found in glaciofluvial deposits of Pleistocene age or in outcrops of Paleozoic bedrock. Glaciofluvial landforms can be located by reference to published surficial geology maps coupled with airphoto interpretation. Preliminary assessment of these features in a large region is most economically carried out during the summer months with a drill that is transportable by helicopter. Once prospective borrow pit sites are identified, a detailed ground-based winter drilling program must be undertaken to establish aggregate quality and quantity, and to provide information on natural features which could affect development. The glaciofluvial terrain has been highly modified by the formation of massive ground ice within the gravel deposits. This presents some unique pit development problems which are not encountered in a normal bedrock quarry operation.

Jan 1, 1977

By J. L. Llanca

The New Level Mine project (NLMP), the planned underground expansion of the El Teniente mine in Rancagua, Chile, is expected to reach a daily extraction rate of 137 to 180 ktpd upon achieving full capacity. Production is planned to start in the year 2017 and the current plan is to meet that target through two development phases, from the year 2012 to 2014 and from the year 2015 to 2017. To achieve the 2012 to 2014 underground development schedule, the ventilation requirements have been estimated in the range of 189 m3/s (400 kcfm), and cannot be made available without significant modifications to the current system of El Teniente. As a result, a certain number of alternatives were explored to find a solution to this shortfall, for example, adding raises to generate parallel airways and installing fans to reinforce the current ventilation system. From the alternatives studied, the installation of a second main fan (system) in parallel to an existing one was identified as the best solution, and selected for implementation, however the location was not ideal and there were concerns as to the operation of both fans once the second fan was installed. This paper presents the study used to estimate the operational points of both the current and the new fan, and to justify the parallel installation of the additional main fan. An additional computational fluid dynamics study was undertaken to validate the operational point, given the particular geometry of the fan?s location and placement, to guarantee a stable operation of the fans. Finally, the protocols arising out of this work for starting the fans, and operating them in parallel to avoid generating a stall condition and damaging the investment are discussed.

Aug 1, 2013

By W. D. Madeley

Synthetic minerals were made from pure starting materials and galena samples were doped with the title metals. Microscopic, microprobe and X-ray examination confirmed that the dopeants were in solid solution. Paired flotations in a Hallimond-tube apparatus were performed to determine relative flotation response using Aerofloat 238 promoter. Results of these tests show that silver-doped galena floats more readily than pure galena and that galena doped with bismuth floats less readily than pure mineral to a 95% confidence level. Galena doped with both silver and antimony as AgSbS2 shows no detectable effect. Antimony-doped galena followed the expected trend, but not to 95% confidence. The results are consistent with the theory that flotation by thiol-type anionic collectors is enhanced by p-type semiconduction.

Jan 1, 1978

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 Burrows. A.

Temperature profiles in the lead smelter sinter bed at Xstrata Zinc Mount Isa sinter plant have been measured using a wireless temperature probe. Corresponding sinter samples have been collected for characterization. The sinter peak bed temperatures were found to be in the range of 1000 - 1200 °C. Microstructures and softening temperatures of these sinters have been characterised. Strong correlations have been observed between peak bed temperature and peak hood temperature, and between mean sinter softening temperature and peak bed temperature. It was found that higher peak bed temperature results in higher sinter softening temperature. For the feed material used in the trials, to obtain sinters with mean softening temperatures above 1050 °C, peak bed temperatures above 1130 °C are required. There appears to be a direct correlation between granule size distribution in the feed and peak bed temperature attained. High peak bed temperatures are observed in sinters with narrow granule size distribution.

Jan 1, 2008

By E. C. W. Perryman

BEFORE describing the methods used for fabricating uranium into various shapes and sizes it is necessary to illustrate briefly the unusual conditions under which uranium has to operate when used as a fuel element in a reactor. During reactor operation, for every fission that occurs two atoms of intensely radioactive fission products are produced together with two or three neutrons. The neutrons that are ejected possess several m.e.v. of energy and when one of them strikes an atomic nucleus, that atom acquires up to 105 e.v. of kinetic energy. This is large enough to displace the atom from its lattice position and send it shooting through the crystal, displacing other atoms out of their lattice positions. The net result is that a large number of vacancies and interstitial atoms are formed within the crystal lattice which sometimes have profound effects on the physical and mechanical properties of the material in question.

Jan 1, 1957

By K D. Conroy

For the past year, Lowphos Ore Ltd. has been operating two desliming hydroseparators on a fully automatic basis. Automatic operation is achieved by sensing the position of the silica-magnetite interface and automatically controlling the jet water addition to maintain a desired interface position. The system further provides automatic control of the underflow pump speed in order to assist in maintaining interface position when an <Ore change occurs. Interface position is maintained at 12 inches below the surface and is -controlled within plus or minus one inch. Metallurgical unit recovery is held above 98.5 per cent, and a 10 to 12 per cent increase in concentrate grade is normally achieved.

Jan 1, 1963

In several European countries, including Russia, it has become economically attractive to utilize peat as a fuel for power generation, the production of metallurgical coke, the production of fuel briquettes for the domestic market and low-Btu gas. Although the economic base and availability of energy supplies in Europe is much different than it is in Canada, regional economics here may warrant the development of peat as an alternative source of energy. Canadian peatlands cover several thousands of square miles and have historically been considered as waste land. Now, with the increasing costs of other energy sources, it is apparent that fuel peat should be re-evaluated as a potential energy resource. A nation-wide inventory of peat deposits has been prepared and reserves evaluated for some of these areas where field surveys have been carried out. The paper describes alternative mining methods developed to meet some of the various conditions encountered on virgin peatland . These mining techniques are generally based on current peat technology exercised in other parts of the world and would be applicable in some of the peat regions of Canada. Cost estimates have been prepared for peat production in regions of Canada, and the socio-economic aspects of a large-scale fuel peat operation are discussed. Several potential utilization schemes have been described, with particular emphasis on electric power generation. The paper makes recommendations for steps to be taken in the development of a fuel peat industry in Canada.

Jan 1, 1978

By Greg Yuriy

Over the past two decades, Vale Canada has used discrete-event simulation in a key role to support many underground mining studies. Traditionally, general purpose simulation software was developed for manufacturing and service applications. Not until recently have Mine Designers and Simulation Specialists been able to model the dynamics of underground mining scenarios without extensive manipulation of the inherent tools and entities contained within these simulation environments. This paper discusses Vale Canada?s past experiences with a variety of simulation software, describing model development methods and highlighting some of the lessons learned. The paper concludes with a review of recently considered software and provides a framework of desired attributes/functions for modeling mining scenarios.

Aug 1, 2013

By Nick Vayenas, Ming Cai, Hongbin Zhang Lorrie Fava, Enrique Acuña

"A hybrid methodology is proposed to improve the accuracy of Diesel Particulate Matter (DPM) concentrations simulated in a ventilation network model by using Computational Fluid Dynamics (CFD). DPM, as a primary concern for underground hard-rock mines, has been studied in two dominant numerical models, ventilation network solvers and computational fluid dynamics. Ventilation network solvers are efficient, but they are not able to provide three-dimensional DPM concentration contours and only accept area-average DPM data as input. CFD simulations are time-consuming, but generating DPM concentration results with high accuracy. Besides, both monitoring points and planes can be created in a CFD model, which can take both point data and area-average DPM data as input. The hybrid methodology is intended to combine the advantages of the two by using the CFD results to update the network model results at key locations. A field study was conducted in a dead-end heading in an underground gold mine in the United States. Real-time DPM monitors were used to collect data. A CFD model and a network model were built for the experiment area. The CFD model was calibrated to the experimental data. In the study presented here, results from a calibrated CFD model are converted to equivalent diesel emission rates in the ventilation network model at a shared outlet. The hybrid methodology is used to provide better input for the network model. INTRODUCTION Mine ventilation system is one of the most important parts for an underground mine. It not only provides fresh air to the personnel but also helps clear the contaminants generated from the diesel-powered equipment. For most underground metal and non-metal mines, diesel particulate matter is the main contaminant. It is also the focus of this paper."

Jan 1, 2019

By Q. Shi, Q. Feng

"The influence mechanism of chlorite on the flotation of pyrrhotite was investigated through flotation tests, Zeta potential measurements, optical microscope photos, solution ion measurements and absorption measurements. It is observed that, the addition of chlorite influences the flotation of pyrrhotite seriously. The IEP (isoelectric point) of pyrrhotite and chlorite is 7.6 and 4.3 respectively, in the condition of slight alkalinity, both pyrrhotite and chlorite are negatively charged, and the hetero-aggregation will not occur. With the existence of oxygen in solution, the iron ions are dissolved from pyrrhotite surface because of the oxidation of pyrrhotite during pulp conditioning. The dissolved iron ions adsorb onto the surface of chlorite in the forms of iron hydroxyl and iron hydroxide, and the adsorption results in the opposite charge of chlorite surface. As a result, the hetero-aggregation between pyrrhotite and chlorite occurs. The adsorption of chlorite changes the surface property of pyrrhotite and restricts the adsorption of amyl xanthate onto pyrrhotite surface, and then decreases the flotability of pyrrhotite.INTRODUCTIONIn sulfide ores processing, magnesium silicate bearing gangue minerals often report to the concentrate causing downstream processing problems as well as increased smelting costs. Talc,chlorite and serpentine are gangue minerals commonly encountered in complex sulfide ores (Engel, Middlebrook, & Jameson, 1997; Pietrobon et al., 1997; Witney & Yan, 1997; Chen, Grano, Sobieraj, & Ralston, 1999a, 1999b; Bremmell, Fornasiero & Ralston, 2005; Senior & Thomas, 2005; Wang, Somasundaran, & Nagaraj, 2005; WieseHarris & Bradshaw, 2007). All of them are characterized with uniform crystal structures consisting of silicon-oxygen tetrahedron and magnesium-oxygen octahedron. The magnesium-oxygen octahedron layers are broken during the liberation of serpentine to expose the magnesium-oxygen bonds with strong ionicity and hydration, which results in natural hydrophilicity of serpentine. In water, the hydroxyl on serpentine surface ruptures and dissolves into the aqueous phase while the Mg2+ remains, resulting in surface positive charge (Tao, 2012). As serpentine has a positive potential at alkaline condition, it is therefore likely that it will attach through electrostatic attraction to the negatively charged mineral surface and reduce both the flotation rate and recovery of target minerals (Lu et al., 2011). For talc, characterized as good natural hydrophobicity, the liberation comes from the interlaminar fracture to remain molecular bonds on surface with weak hydration. Being naturally hydrophobic, talc easily reports to flotation concentrates, thus reducing concentrate grade (Shortridge, Harris, Bradshaw, & Koopal, 2000; Beattie, Huynh, Kaggwa, & Ralston, 2006). Meanwhile, both molecular bonds and magnesium-oxygen bonds are exposed on chlorite surface when liberation occurs, resulting in moderate natural hydrophobicity between serpentine and talc (Tao, 2012). And thus the mechanisms of influence of chlorite on sulfide ores are more difficult to study."

Jan 1, 2016

By R. J. Enkin

Modern mineral exploration depends on multidisciplinary 3-dimensional integration of geological and geophysical data. Identification of the geological sources of geophysical anomalies requires knowledge of the physical properties fingerprint of rock types, formations and their alteration products. Understanding how and why rock physical properties vary within the Earth&apos;s subsurface ensures that appropriate geophysical exploration methods can be chosen, and allows for more efficient and effective surveys to be designed. Physical properties knowledge is integral to geophysical modeling - measured data or values estimated based on geological understanding are used to produce realistic forward calculations and to constrain inversion models. Mira Geoscience and the Geological Survey of Canada, in collaboration with industry and academia, are building a Rock Properties Database System (rpds.mirageoscience.com). It compiles the most valuable physical properties for mineral exploration (density, porosity, magnetic susceptibility and remanence, electrical resistivity and chargeability) linked with location and lithological metadata. A critical knowledge gap, addressed in this study, concerns the dependence of physical properties on alteration and mineralization processes. We report on the results of a collaborative University of British Columbia - Geoscience British Columbia project, ?Integrated Geological & Geophysical Porphyry Models: Adding Value to Geoscience BC Geophysical Data?. As part of the QUEST and QUEST-West geophysical initiatives, Geoscience BC focused detailed geophysical surveys on a suite of six known porphyry deposits: Mount Milligan, Endako, Huckleberry, Bell, Granisle, and Morrison. Physical properties for a set of 269 samples of characteristic host rocks and their altered equivalents were measured. The causes of physical properties variations were investigated through their correlations with ore and alteration mineralogy determined from thin-section observations and X-ray diffraction analyses. Physical properties of variably altered host-rocks and intrusive rocks vary significantly between different BC porphyry deposits. No specific unifying geophysical model exists that can be uniformly applied during exploration. Knowledge of local background geology and local physical properties variations is necessary as host-rocks and intrusive rock compositions vary depending on magmatic affinities, and alteration styles will vary reflecting host-rock compositions, crustal depth and influence of meteoric water. A district-scale exploration strategy requires location of intrusive bodies, which are commonly magnetic, resistive and low in density. Correlations should not be expected between density and magnetic susceptibility, because alteration may lead to magnetite destruction or to secondary magnetite development. Deposit-scale ground geophysics might image potassic alteration zones that can be magnetic in both alkalic and calcalkalic systems. Low magnetic susceptibilities, resistivities and densities might aid in locating the typically more porous phyllic and argillic zones. All geophysical data must be interpreted with background knowledge of local rock types and in light of the expected deposit model and associated magmatic and hydrothermal processes. The most effective means to building physical properties knowledge prior to geophysical investigation remains collecting rock physical properties measurements. The cost of rock properties data collection is low, relative to the overall costs of running a mineral exploration program, and can provide an important framework for design of geophysical surveys, survey method selection, geophysical modelling, and data interpretation.

Aug 1, 2013

By E. Brzychczy

Artificial intelligence techniques are ever more frequently implemented in the modern world. One of their numerous uses is supporting enterprise management. Intelligent techniques and intelligent information technology (IT) systems can be implemented in mining-related issues as well. The author of this article concentrates on supporting the process of planning mining operations by intelligent systems and techniques. The author also underlines the importance of knowledge accumulation in a mining enterprise (especially tacit knowledge) as well as its efficient storing and using. Additionally, the author provides a short description of characteristics of intelligent IT systems and indicates their capabilities in planning mining operations. She presents two solutions, namely: an advisory system which supports the process of planning preliminary works and exploitation works in hard coal mines, and a method of modeling and optimizing mining operations. Finally, the author indicates a few possible future development trends of intelligent systems - the intelligent systems of decision support.

Aug 1, 2013

By J. A. Vonhof, R. O. van Everdingen

Since 1949, a total of 59 disposal wells have been installed in Canada to inject liquid wastes from refineries, mining operations and chemical plants into subsurface formations at an ever-increasing rate. Well depths range from around 600 feet to almost 5,500 feet; injection rates range from 0.5 (U.S.) gpm to more than 1,000 gpm for individual wells; wellhead injection pressures range from a slight vacuum to over 500 psi. Apart from strictly technical considerations of well design, the geological, hydrodynamic and hydrochemical conditions at the disposal site have a strong bearing on the safety and success of such operations. Prevailing hydrogeological conditions in large portions of the country do not allow safe subsurface disposal.

Jan 1, 1973

By G. F. Liu, S. Owada

Platinum Group Metals (PGMs), Pt, Pd, Rh, have been widely used as a three-way catalyst to clean discharged gas from automobiles and therefore a considerable amount of the spent catalysts is generated annually. This paper proposes a novel concentration technology of PGMs by utilizing the double-deck structure of PGM bearing alumina-ceria and cordierite phases. The applied technologies are a combination of heating-quenching, selective grinding and screening for separating alumina-ceria phase from cordierite. Temperature change as a function of quenching time and the thermal stresses applied to both phases were simulated and calculated by FEM, and it was clarified the mechanism of micro-cracks generation at the phase boundary and micro-cracks in alumina-ceria phase, which indicated that separation of alumina-ceria phase from cordierite and selective breakage of alumina-ceria phase could be achieved in the subsequent selective grinding with an attritor. This process could concentrate 46 wt% of alumina-ceria phase into fine fractions with 86 % recovery efficiency. The remaining alumina-ceria phase can be further recovered by applying flotation and so on.

Jan 1, 2015

RÉSUMÉ Cet article traite d’une analyse technique et économique du concept du triage optique en vue d’améliorer la rentabilité des opérations minières. Le principe du tri optique et les principaux systèmes et modules servant au fonctionnement de l’appareil de triage sont décrits. un modèle a été développé pour analyser l’intérêt économique d’une opération de triage optique. L’étude est basée sur des données provenant d’une halde de minerai à faible teneur en or, déposé à la surface, et de minerai extrait des opérations souterraines courantes de la mine Beaufor au Québec. Les résultats de cette analyse indiquent que l’opération de triage optique permet d’améliorer grandement la performance économique; l’opération devient alors rentable pour des teneurs en or relativement petites.

Jan 1, 2010

By Chris Harris, Kamal Adham

The use of HCl acid is gaining momentum among hydrometallurgical processes. However, the issue of environmentally efficient and economically viable ways to regenerate HCl acid (from various metal chloride intermediate products) remains a technology and operational challenge. The authors provide a state-of-technology review based on Hatch’s years of testing, design and commissioning experience with high-temperature units (fluid bed and spray roasters), plus the recent efforts in the area of low-temperature HCl regeneration.

Jan 1, 2014

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 F. W. Tregarthen

"This paper gives a brief description of the methods used to form and implement the present planned maintenance program. The system is designed to assist plant personnel in their task of controlling a large work-force and maintaining the many and varied types of equipment used in a mining and concentrator operation. The types of reports and methods used in scheduling and work-loading are described. General built-in flexibility is derived from computer assistance to the Central Planning Group."

Jan 1, 1971

By C. Lambert

It has been shown that contacts between host rock and engineered barriers may be critical in the design of deep radioactive waste repositories. Water is expected to reach the interface zone after the re-saturation of the geological massive and its presence may lead to concrete leaching. Such a phenomenon could increase the interface transmissivity and compromise the confinement of radioactive waste. Recent experimental results from Buzzi et al. (2008) have enhanced how concrete leaching can drastically change the mechanical behaviour of such interfaces. Because of the local loss of strength resulting from leaching, shearing resulted in a degradation of the interface asperities. Similarly to rock joints, intact interfaces exhibit a usual contracting-dilating behaviour. On the contrary, depending on the extent of leaching, the degraded interface can display a fully contracting. This paper intends to investigate the influence of concrete leaching on the mechanical behaviour of host rock-concrete interfaces. The leaching process consists in the dissolution of some of the hydrates of the cement paste, leading to a reduction of the strength and Young&apos;s modulus. A discrete model has been developed with PFC3D where a simplified interface morphology has been introduced using a saw-tooth description of the asperities.

May 1, 2009