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By R. Lovat, J. A. Hunter

"The design, development, and verification of the Lovat 7.6metre diameter full-face tunnel-boring machine is reviewed. Programmatic and technical challenges are outlined with a review of the specifications and the design to meet these requirements. Subsystem designs are presented for the waste material removal, ventilation, cutter head, structural support, advance technique, water removal, and interfaces with the Donkin-Morien Mine. The techniques used to verify that the design meets the requirements is by testing in the Lovat factory and in the field. Certification of the machine for use in a methane environment is discussed.IntroductionStudies have concluded that the average annual worldwide tunnel construction is 500 kilometres at an estimated average co st of $3,400 U.S . per linear metre. The total market value of the tunnelling industry is estimated as approximately $1.7 billion U.S. per annum. Of this, the current market for tunnelboring machine excavation is approximately $270 million U.S. per annum worldwide with a further potential of $250 million if more contractors are convinced that Tunnel-Boring Machines (TBM) are more suitable than conventional techniques. The worldwide civil tunnelling market has the potential to double each year in the next 5 to 15 years. Growth has been identified in the energy and mineral resources sectors of the economies of many nations and a significant volume of machine tunnelling studies and trials are presently underway for the extraction of coal, uranium , heavy oil or oil sand fuels, metallic and non-metallic industrial minerals and base metal or rare earth ores. Further tunnel projects for regional transportation, waterpower, irrigation , high density urban transportation, storm water sewers and water supply purposes are continually being implemented with new concepts like military security facilities and underground storage schemes being considered.Lo vat Tunnel Equipment of Rexdale, Ontario, the only Canadian manufacturer of TBMs was incorporated in 1973 to manufacture so ft ground tunnel-boring machines to satisfy this growing market demand. Lovat has produced an average of 5 machines per annum during the period 1972 - 1982 and has established an international reputation for competitive costs, quality of construction, after-sales service, and reliability. As of June 1982 Lovat TBM's have been used to tunnel over 240 km in projects throughout the world."

Jan 1, 1984

By Z. Q. Yue

Many large rock avalanches and/or landslides have occurred in mountainous regions around the world. Their occurrences are normally rapid and unexpected, which can cause disasters. They have been investigated extensively by many researchers and engineers since the 1903 Frank Slide on Turtle Mountain, Alberta, Canada. They are one of the most peculiar phenomena because the rock debris of more than one million m3 can move over the horizontal distances exceeding those expected from conventional friction physics. This paper presents a gas cause hypothesis responsible for the large rock avalanches. It is the migration and expansion of a certain amount of highly pressurized and dense natural gas mass from deep geological grounds into the mountainous rock mass slopes. The natural gas with high pressure and density can escape from the deep geological ground and flow through faults, weak zones and/or porous channels into the rock mass forming a mountainous slope. The rock mass forming the slope has the high tensile and compressive strength and can resist the initial loading of the gas mass migrated into and stored in their voids, pores, holes, gaps, openings, apertures and cavities. With time, more and more gas mass from deep ground can migrate into and stored in the slope rock mass. Eventually, the peak equilibrium of forces and deformation reaches. The expanding power of the gas in the slope rock mass would instantly and rapidly break, erupt and/or explode them. The compressed and dense gas mass would mix, flow and expand together with the broken rock debris mass and continue offering their remaining expanding powers to the moving and sliding debris mass. As a result, the rock debris of large volume can reach the runout distances exceeding those expected from the conventional friction physics. The gas would escape into the sky and the solid rock debris would remain on the ground spreading over large ground area. The 1903 Frank Slide is examined to show this gas cause and mechanism in mountainous regions.

Jan 1, 2015

Building block cave operations involves significant commitments to capital and time before arriving at completion or full scale production. The focus of the mine planners is habitually to minimize the upfront capital and achieve target development rates and construction dates. However, management of the construction of block cave projects requires understanding of the strategic/tactical decisions that the project planners can take to increase the value of the project and cope with schedule risks. As block cave projects involve development of vertical and lateral access to the underground footprint and ore body, more attention to uncertainties is required as most of those projects need to confront delays leading to a decrease in value. The standard process of development and construction scheduling is often not planned with provisions to realise uncertainties in the construction phase. Uncertainties and risks such as poor ground conditions and equipment breakdowns are the primary reasons for schedule slippage. As a result most of these projects experience delays. In order to mitigate risk to the project schedule, we centre our attention on increasing the value of the project by spending more money upfront and improving the schedule rather than focus on minimizing the upfront capital. Scenario-based simulations along with project appraisal methods hold great promise to address those challenges and enable mine planners to make better decision and enhancing project value. This paper will present a hybrid simulation based approach to model the process of development and construction based on discrete event (DES) and continuous based simulations (CBS). Such simulations will be conducted for scheduling multiple development headings (Apex, undercut, extraction, and haulage levels). Two scenarios are utilized to investigate the impact of risks on schedule and how flexibility in construction can be incorporated to minimize delays: (1) The bench mark scenario is created based on actual data from an existing case study. (2) The flexible scenario is an alternative way to use primary production infrastructure (Ore Handling System) including conveyer drifts, conveyer belt, and a gyratory crusher in the construction process and that requires the system to be in place before starting lateral development in the footprint. As a result, a truck-load system versus a conveying system will be studied to observe the gain in construction speed and to estimate the premium cost for mucking rock from headings and drawbells and transporting it to surface. Such strategic flexibility would be part of the original budget to make the tactical flexibility available during construction. Continuous cash flow models are used to evaluate and compare the scenarios. This study is an example of how new techniques in planning can be used to support decision-making processes in block cave design.

Aug 1, 2013

By C. J. Simensen, R. Østhus, H. J. Roven, K. G. Skorpen, H. Kalager

"This work encompasses co-extrusion of alloy Al4.5Mg at the core and rapidly solidified Al4.5Mg1Ag forming the surface layer. The goal is to produce a multi-material by co-extrusion having a relatively hard surface as compared to a softer core. At the same time, work hardening in both alloys is expected to be significant due to Mg in solid solution. Precipitation hardening at 160°C is studied by applying solution heat treatments at 560°C. The hardness increased from 80 to 130 VH in the surface material after 236 h. Surprisingly, the Al4.5Mg alloy also shows pronounced aging at this temperature, i.e. from 70 to 90 VH. The relatively high solution heat treatment temperature introduces grain growth in the core, but this is insignificant for the RS surface alloy. Blisters forms at the surface and cracks follows large portions of the interface. However, the tensile ductility is significant in all conditions due to very pronounced work hardening, i.e. for the as co-extruded, T6, under- and over-aged. The elongation at fracture ranges between 40–45% and the tensile strengths 240–275 MPa. The tensile properties increase linearly with the thickness of the RS alloy, i.e. following the rule of mixtures.INTRODUCTION Al-Mg alloys in 5xxx-series are classified as non-heat treatable wrought alloys (Polmear, StJohn, Nie, & Ma, 2017). The formation of the binary ß-Al8Mg5 does not give a substantial increase in the strength of the alloys (Mondolfo, 1976). When a third element like Ag, Cu or Zn are added, G.P.?zones are formed at low temperatures and intermediate, partial coherent phases are nucleated somewhat higher temperatures and finally a ternary, equilibrium phase is formed (Auld, 1968; Cousland & Tate, 1986; Mondolfo, 1976). Both the formation of G.P.?zones and intermediate phases increase the hardness and strength of the materials. An intermediate, hexagonal T´?phase is formed in Al-5 wt%Mg-1wt%Ag, and finally the equilibrium, cubic phase (Al,Ag)9Mg5 is nucleated (Cousland & Tate, 1986; Mondolfo, 1976)."

Jan 1, 2018

By S. Koppalkar

ABSTRACT: The development and evolution of the gravity recoverable gold (GrG) test procedure at McGill university is reviewed in this paper. Since the late 1980s, the research group led by the late Professor André Robert Laplante at McGill university has undertaken fundamental studies and applied research of the Knelson concentrator to develop a sustainable method of estimating GrG. Historically, a concept of “free gold” was used, and it was de?ned as the gold that could be separated and recovered from gold ore by amalgamation. Due to health and safety hazards, the practical use of amalgamation has declined. around 1994, a methodology using a 3-in Knelson concentrator to measure gravity recoverable gold was established at McGill university. as a result of more than 10 years of improvement and optimization, this technique has become a standard method of evaluating GrG for gold ores, gold plant streams and platinum group metals. By 2006, about 200 GrG tests were carried out at McGill universityon ores from all over the world. recently, a modi?ed version of the GrG test (a simpli?ed test) was developed to provide a quick and rough estimate of the GrG in a sample; this simpli?ed test has theadvantage of reduced mass, processing time and cost. to recognize and honour the contributions madeby the late Professor Laplante towards the establishment of a standard test procedure for assessing gravity recovery potential, the authors propose that the GrG test be named after Laplante.

Jan 1, 2010

By I. P. Swainson, A. Ilbagi, H. Henein

Powders of Al-50wt%Ni, Al-40wt%Ni and Al-36wt%Ni were produced using the Impulse Atomization technique, a rapid solidification technique. The molten droplets were cooled in-flight by the stagnant helium or nitrogen in the atomizing chamber. The resulting powders were sieved into different size ranges. X-Ray diffraction and neutron diffraction were used in order to quantify the phase fractions in the samples. The computer software GSAS was used to calculate the weight fraction of the existing phases, namely Al3Ni2, Al3Ni and Al, by profile refinement method. The effect of processing parameters, alloy composition and particle size will be discussed in this paper. In brief, no AlNi was found in any of the samples analyzed. Higher cooling rates resulted in the reduction of the ratio of Al3Ni/Al3Ni2. Also, at high cooling rates, Scheil closely predicted the ratio of Al3Ni/Al3Ni2. Some metastable phases were found in Al- 36wt%Ni.

Jan 1, 2010

By David Eichenberg

A154S A154N After 3 Years of Mining ?Current mining Level A154S 280RL ?110 Vertical metres of A154S ?Current mining Level A154N 300RL ?100 Vertical metres of A154N ?Variations in Kimberlite Volume ?Ore Types and Plant Production

May 1, 2006

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 C. D. Smith

Numerous studies have shown the potential of air rate profiling to significantly improve the flotation performance of a bank of cells. To date many profiles have been implemented; balanced, increasing, decreasing and combinations of these. Previous work has typically shown using an increasing air rate profile, where the air rates are increased proportionally to each cell down the bank, yields a higher grade for a given recovery compared to other profiles. Air rate profiling can then be thought of as having two distinct components; determining the correct distribution of a given volume of air and, perhaps more importantly determining the correct total volume of air to add to the bank. To date no method for this second component has been established. In an alternative technique the air rate to each cell is adjusted in order to optimise the air recovery from that cell. Air recovery is the fraction of the inlet air which overflows the weir of a cell as unburst bubbles. The peak in air recovery (PAR) is a robust measurement that indicates optimal performance for the operating conditions in the cell, and sets the PAR air rate. By doing this for each cell in the bank, the optimal total air rate to the bank and the optimal distribution of that air can be simultaneously determined. In this study plant trials evaluated different air rate profiles, and profiling based on PAR. The total air rates to the bank for all profiles tested were approximately equal, allowing direct comparison. The results showed that the highest cumulative mineral recovery was achieved by operating at air rates which gave the PAR for each cell down the bank. Different distributions of the same total air rate to the bank gave the same cumulative upgrade ratio, but lower cumulative recoveries. In this study, the increase in cumulative mineral recovery, at the same upgrade ratio, was more than 33%. Peak in air recovery (PAR) based optimisation of air rates to banks of cells and to the individual cells has been shown to significantly improve flotation performance as it simultaneously determines the optimal air rate to the bank, and the optimal distribution of that air.

Jan 1, 2009

By E. G. Gaylord

THE material improvements which have been made in the practice of exploiting oil and gas reservoirs in the United States during recent years may be attributed largely to: (1) The necessity for drilling deeper wells at costs not much greater than was formerly expended on shallower wells. (2) The necessity for producing oil at a lower cost per barrel. (3) A growing recognition of the importance of the nature of production practice upon ultimate yield of oil and gas. The first two of these factors result, to a large extent, from the fact that a greater proportion of new development has been deeper development, and these wells have been drilled in the face of progressively lower per well allowables. In California, for instance, maximum allowables have declined from 400 barrels per day in March, 1938, to 156 barrels per day in September, 1940, and during this same period some 125 wells were drilled to the deeper 10,000-foot producing horizons discovered during this time. The third item listed above results from our increasing knowledge of the basic factors which influence the amount of recovery we may expect from reservoirs. In addition to the longer-range planning now being undertaken by the more prudent operators, State proration and conservation laws have focused attention upon the importance of methods conducive to obtaining progressively greater quantities of the hydrocarbons in place. In a paper of this length it will be possible to discuss only a few of the recent advances. An effort has been made to select the more important of these and to indicate, where possible, the factors which have made these advances possible.

Jan 1, 1941

By A. C. Hatton

Doped SrCoO3.8 was found to be a promising material for use as a cathode component in intermediate temperature SOFCs. In this work, strontium cobaltite ceramics doped with 10 mol% to 90 mol% samarium were synthesized using the glycine nitrate process in order to study the electrical conductivity and thermal expansion at temperatures of up to 800°C. As-synthesized powders were deagglomerated, pressed and sintered at temperatures ranging from 1100-1250°C. The effect of temperature and composition on electrical conductivity and thermal expansion are presented and discussed.

Jan 1, 2005

By Radford B. Langston

Mining Methods Majority of Production Ramp and Fill at Stillwater, Sub-level Becoming More Important Production at East Boulder from Sub-level l Majority JM REEF ROCK TYPES NORITE - plagioclase and bronzite cumulate GABBRONORITE - plagioclase, augite, and bronzite cumulate TROCTOLITE - plagioclase and olivine cumulate ANORTHOSITE - plagioclase cumulate PERIDOTITE - olivine cumulate

May 1, 2002

By J. L. Barton, R. A. Murray

"This paper looks at how Syncrude Canada Ltd. is utilizing the Conveyor Belt Monitoring technology developed and patented by the Australian CSIRO and licensed to Syncrude by Conveyor Belt Monitoring of North America, Inc. The technology involves magnetizing the steel cables in the conveyor belts and detecting the fields produced by breaks, gaps or cable ends using special sensors which feed the signals into a multi- channel recorder to provide permanent traces of the various events taking place in the steel cable belts.The data is analyzed and combined with existing belt audit programs, to assist in predicting belt life, change-out criteria and belt design, belt loading and construction. All of these applications of the CBM technology leads to better utilization of resources and forms an integral part of the conveying system reliability program."

Jan 1, 1992

By H. A. Kee

In the mining industry, as in other business, one of the more satisfactory results of sincere but cheerful effort lies in the proper completion of undertakings and problems, which, to be successful, must continually hold the interest of all concerned in the work. In most undertakings, genuine interest and satisfaction is largely dependent on the proper appraisal of opportunities presented, and the opportunity to associate ourselves with sinking operations at McIntyre central shaft, from the surface to a depth of 4,133 feet, was genuinely appreciated. This opportunity was made possible by the previous persistent and successful leadership of Mr. J. P. Bickell, President, with the assistance of his associates, and of the general manager, Mr. R.J. Ennis, in the development of the McIntyre Porcupine mine, and I beg to state that any success in this sinking operation was very largely due to the congenial co-operation and splendid workmanship of Captain Martin C. Horne, his shift bosses, leaders, and all those who worked with us . Our slogan throughout was " Safety First for Pleasant and Efficient Workmanship," and this general policy made it possible to sink and timber 2.,123 feet during the first year without a serious accident.

Jan 1, 1928

By J. Kouam

Al-Si-Cu and Al-Si-Mg alloys are widely used in several applications. Although they can be produced near-net-shapes, products made of these alloys very often require some machining. The purpose of this study is to evaluate the machinability of A319 and A356 under TO and T6 conditions. The machinability was assessed using during dry drilling machining process and the machinability indexes used are the chip form, the chip breakability and the cutting forces. It is found that 319 and 356 exhibit different machinability behaviors, especially in the T6-condition in terms of forces requirements, chip breakability and chip segmentation. It is also found that both the microstructure of the workpiece materials and the machining conditions significantly affect the chip formation mechanism, and therefore, the machining parameters could be selected to promote a chip form that is easily manageable in production.

Jan 1, 2011

By E. L. Martheleur

A general expression for the electric power generated or consumed in a direct-current circuit is obtained by multiplying the reading of a suitable voltmeter connected across the terminals by the reading of an ammeter connected in the circuit. by the reading of an ammeter connected in the circuit. When alternating currents are considered, the product of the volts and amperes as obtained for direct currents does not generally represent the true energy involved; it is greater than this true energy and should be multiplied by a certain factor which may have any value between zero and unity, according to the conditions of the circuit. This factor is called the power-factor of the system, and expresses the ratio of the true energy over the apparent energy. For a three-phase system the expression of the apparent energy is [\/ 3 x E x I; ] while the expression of the true energy, that is, energy suitable for mechanical work, is [v? 3 x E x I x cos A.] The total current of a circuit corresponds to the reading of an ammeter connected in the circuit; it is the resultant of two currents. The first of these is in phase with the voltage, and is that portion which really produces mechanical work; the second is always in quadrature with the voltage, that is it may lead or lag the voltage by 90° according to the condition of the circuit. This second current does not produce any sensible work, and for this reason is sometimes called wattless current or reactive current.

Jan 1, 1924

By T. S. Golosinski

"This paper reviews the types of selective continuous miners (SCMs) available at present, and compares their main features. Furthermore, operating practices and mine planning aspects of the SCMs applications are reviewed and conditions for efficient application of this equipment are defined. Finally, the potential applications of the SCMs in surf ace mining of oil sands are discussed INTRODUCTIONIn the 1970s the United States Bureau of Mines (USBM) conducted a program of investigations, design and demonstration of various continuous surface mining concepts, This included continuous mining equipment which was an adaptation of several civil engineering and/or underground mining machinery concepts to surface mining. Upon termination of this program, the related development was continued by a number of equipment manufacturers, leading to development of several types of SCMs. This new type of surface mining equipment is able to mine selectively hard and thin multi-layered formations at high, sustained, and economically viable production rates.While used mostly in coal mining at present, the characteristic features of this equipment permit conclusion that it may prove to be an efficient tool for surface mining of oil sand, and/or related overburden stripping. Of particular interest here may be the ability to mine thin layers of hard material, without a need for its earlier fragmentation, and the ability of the SCMs to load a variety of haulage equipment, including belt conveyors."

Jan 1, 1989

By Alf Hartling

"Most of the Paleozoic section of the Williston Basin is a thick accumulation of numerous carbonate to evaporite, shallowing upward, cyclic sequences. These sediments were deposited in broad epeiric seas, and the deposition of the evaporite facies marked the final stage of each cycle. Many of the sequences display a pervasive replacement dolomite in the uppermost portion of the carbonate units. This secondary dolomitization is, at least in part, an early diagenetic event, synchronous with evaporite deposition.The inception of evaporite precipitation resulted in the seepage of a dense, Mg-rich brine into the underlying sediment. The heavy brine moved down the gentle regional dip displacing the more normal marine interstitial pore fluid and dotomitized the primary calcitic sediments en route. The supply of Mg-ions decreased away from the source, and correspondingly, the degree of dolomitization decreased and larger crystals formed because of slower nucleation at fewer sites.The seepage refluxion of dolomitizing brines gave rise to the frequently observed textural variation of cryptocrys talline, impervious dolomite grading into a finely sucrosic, permeable dolomite down-dip. This diagenetic facies change provides the critical up-dip barrier for potential hydrocarbon reservoirs. The lateral pool boundaries are controlled by either structural relief or a similar diagenetic facies change. The reservoirs are capped by the tight evaporites.Hydrocarbon production is attained from diagenetic traps in the Mississippian Oungre Zone and the Ordovician Red River 'C' Zone . Reservoir creation and the pooling mechanism are the result of dolomitization by the seepage refluxion of dense, Mg-rich brines beneath restricted, hypersaline lagoons. When formulating an exploration/ exploitation program for these oil prone horizons, it is essential to understand the complete geological history in order to establish where the reservoirs will be found and to define the areal extent of each accumulation."

Jan 1, 1984

By Greg M. Hollyer

The search for minerals in the future will be dominated by deeper exploration and the need to accurately target ?blind? deposits as more and more of the ?easy? near surface targets are exhausted. In this context, key technologies are emerging for deep exploration both in grassroots and minesite exploration, including the Titan 24 Deep Penetrating geophysical technology. Introduced in 2001, this technology has grown rapidly into an accepted approach for exploration in a variety of geologic environments, including brownfield environments where discovering additional reserves would most quickly benefit companies. Titan 24 belongs to a new class of sophisticated Distributed Acquisition Systems (DAS) which record high-volume, high-quality data simultaneously at multiple receiver stations. This data is then processed digitally, modeled using specialized inverse modeling software, and interpreted according to geologic and other parameters. The result is a robust, high-quality, high-volume data sets which provide a basis for improved imaging to depth. In this paper, the Titan 24 distributed technology is discussed. Illustrations of the vast improvement to overall exploration are showcased through results in several case studies. These include examples from two gold deposits, a porphyry deposit and a minesite. These examples show the range of applicability of the technology and the ability to effectively image mineralization, lithology, structure and alteration to depth as an aid to understanding prospective mineral deposits and targeting drills more accurately.

May 1, 2008

By Lorant B. Geller

Sixteen miners died tragically at the Paymaster gold mine at Timmins, Ontario in February, 1945, when a badly corroded hoist rope broke. The investigation of the Royal Commission that followed arrived at a number of recommendations (Investigations, 1947) aimed at avoiding future disasters of this kind. One consequence was the development, and legislated use in Canada, several decades ago, of powerful electromagnetic (EM) instruments for the nondestructive testing of mine shaft wire ropes. The authors have been involved for many years in the design, production, and testing of EM instruments (Geller and Udd, 1990 and 1992, Geller and Kitzinger, 1991, Geller et al., 1993). Since the mid-1990s particular attention was paid to the design and operational results obtained from the computer- controlled portable MagnographJ II wire rope tester (Geller et al., 1995 and 1998). In the present article the authors summarize further hardware- and software-related developments of this instrument. Further, an account is given of the results obtained from the most recent design known as the PermaScanJ testing system. This is also a computerized dual-function system. In it, however, the sensor head is designed primarily, if not solely, for permanent installation and for remotely controlled operation. This represents a basic departure from traditional designs, which were intended for ad hoc temporary installations. The remotecontrolled instrument described in this paper has now been in operational use for more than 4 years.

May 1, 2003