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By Paolo Farina

Slope monitoring radar has emerged in the last ten years as a leading edge tool for monitoring movements in natural and engineered slopes, thanks to its ability to rapidly measure slope movements with millimetric accuracy over wide areas in any weather conditions, obviating the need to install artificial reflectors. In recent years, slope monitoring radar has experienced significant improvements in its performances, mainly thanks to the use of different radar technology, such as Synthetic Aperture Radar (SAR), able to overcome some of the limitations of the first generation of radar and to provide higher spatial resolution, longer working distances and faster acquisition time. One of the leading applications of this technology is today represented by slope monitoring within the surface mining industry. Prominent international mining groups currently employ slope monitoring radar, based either on Real Aperture Radar (RAR) and SAR technology, for active and background monitoring of open-pit walls. The main technical features of typical slope monitoring radar based on SAR technology along with their possible applications are presented in this paper along with recent case studies of successful slope monitoring in open pit mines.

Jun 1, 2012

"The main purpose of geometallurgy is to develop a model to predict the variability in the mineral processing performance within the ore body. Geometallurgical tests used for developing such a model need to be fast, practical and inexpensive and include as an input data relevant and measureable geological parameters like elemental grades, mineral grades and grain size. Important in each geometallurgical program is to define the number of samples needed to be sent for geometallurgical testing to enable reliable metallurgical forecast. This is, however, a complicated question that does not have a generic answer.To study the question on sampling a simulation environment was built including a synthetic ore body and sampling & assaying module. A synthetic Kiruna type iron oxide - apatite deposit was established based on case studies of Malmberget ore. The synthetic ore body includes alike variability in rock types, modal mineralogy, chemical composition, density and mineral textures as its real life counterpart. The synthetic ore body was virtually sampled with different sampling densities for a Davis tube testing, a geometallurgical test characterising response in magnetic separation. Based on the test results a forecast for the processing of the whole ore body was created. The forecasted parameters included concentrate tonnages, iron recovery and concentrate quality in terms of iron, phosphorous and silica contents.The study shows that the number of samples required for forecasting different geometallurgical parameters varies. Reliable estimates on iron recovery and concentrate mass pull can be made with about 5-10 representative samples by geometallurgical ore type. However, when the concentrate quality in terms of impurities needs to be forecasted, the sample number is more than 20 times higher. This is due to variation in mineral liberation and shows the importance of developing techniques to collect qualitative information on mineral and ore textures in geometallurgy."

Jan 1, 2016

By Z. Zhang, M. -Y. Liu, X. -G. Chen, F. Breton

"The microstructures of AlSi10Mg foundry alloy in permanent mould (PM) and high pressure vacuum die (HPVD) castings were analyzed and compared. The as-cast microstructures of two castings mainly consisted of eutectic silicon particles, primary Mg2Si and Fe-rich intermetallic phases. The surface layer in HPVD castings, which has a unique feature and different structures, was carefully characterized. The dimension variation of microstructural phases along the cross section in PM samples is less than that in HPVD samples, although the size of microstructural phases in PM samples was much larger than that in HPVD samples. The mechanical properties of PM and HPVD samples were evaluated on as-cast and T6-treated conditions. The tensile properties of HPVD castings are remarkable better than those of PM castings on the as-cast condition. The T6 heat treatment greatly improves the tensile strength of PM castings while it has limited impact on the tensile strength of HPVD castings.INTRODUCTION The AlSi10Mg alloys are widely applied to the high pressure die casting (HPD) and high pressure vacuum die casting (HPVD). In the HPD process, the melt is injected into the die cavity under a high speed (30–50 m/s in the gate velocity for aluminum alloys), and solidified under a high pressure (up to 200 MPa in the cavity) and with a high cooling rate (up to ~103 Ks–1) (Gourlay, Laukli & Dahle, 2007; Ji, Wang, Watson & Fan, 2013). This results in a unique microstructure feature that is different to other casting processes under gravity. One major concern in HPD castings is porosity due to trapped air in the cavity (Ji et al., 2013), which seriously restricts the application of a heat treatment on the improvement of mechanical prosperities because of the formation of blisters on casting surfaces. For the process improvement, the high pressure vacuum die casting was developed in 1980s (Uchida, 2009). In this process, the melt is injected into the die cavity under reduced pressure (vacuum), which greatly reduces gas porosity in castings due to effectively avoiding the trapped air. Consequently, HPVD castings are heat-treatable without the formation of blisters on castings surface during heat treatment. The HPVD process has been widely applied to produce high quality structural castings in recent years attributed to reliable vacuum system development (Uchida, 2009). However, the microstructure features of HPVD castings are not systemically characterized yet."

Jan 1, 2018

By W. E. Lockley

This paper will attempt to answer a number of questions which are important to the safe and continued operation of an electric power system. 1. WHY should electrical protective devices be tested? 2. WHAT devices should be tested ? 3. WHEN should they be tested ? 4. HOW should they be tested? 5. WHO should test them ?

Jan 1, 1977

By Abhiram Shankar

Construction projects are becoming more demanding both in terms of time and complexity. This necessitates intricate planning and sequencing of activities at the macro and micro level and continuous flow of resources across the project in order to achieve planned targets. Work and Resource planning need to be done in such a way that limited resources give optimal output. Currently dominant activity-based scheduling techniques like Critical Path Method (CPM) and Program Evaluation and Review Technique (PERT) do not model work-flow or resource-flow through a project life cycle. An extension to the conventional activity based planning is Location Based Management System (LBMS). LBMS has been explored and utilised in the case of repetitive and cyclic projects such as high rise buildings. This study focusses on the application of LBMS to repetitive and non-repetitive components of Power Transmission and Distribution (PT&D) projects involving construction of substation and cable laying. This paper presents the findings on comparing the current planning practice for cable laying with an LBMS based approach. A key finding of the study was that the conventional practice resulted in a schedule with several coordination issues that could not be identified in the planning reports. Using the LBMS based approach these issues could be identified and decisions required for resolving these could be made.

Aug 1, 2013

By J. G. Thomson

Development of the Canadian North, a subject of growing national interest, must in part await the development of better forms of trans-port. The estimated 500,000 square miles of muskeg terrain in the north combined with the" scarcity of roads make essential the early development of special purpose muskeg vehicles. Good progress has been made in the last eleven years in classifying muskeg and some progress has been made in determining its mechanical properties. Limited travel is now possible through the use of special purpose tracked vehicles which have been built without adequate design data. A program to provide data which can be used to optimize muskeg vehicle designs began in 1957. The results of the second phase of this pro-gram are presented in this report. It is shown that vehicle performance in muskeg is directly related to the mechanical properties of the muskeg. Further, it is shown that good de-sign practice for tracked vehicles expected to operate in snow, sand, soft clays and loams is also good practice for muskeg vehicles. All indications are that muskeg mechanics is properly a part of conventional soil mechanics.

Jan 1, 1961

By William B. Hetherington

Communities are the foundation upon which the whole structure of society rests and upon which the nation builds its hope for the future. They are not established to serve any one particular generation, nor any one element or group, but should be erected to render a lasting service to all who are to follow. They play a very vital and important role in the lives and welfare of the people, in their industrial, business, and social relations, and in the economy of the nation, of which they are the fundamental assets. Communities and civic governments are destined to be vital factors in the national welfare in the days that are to come. Any improvement in national or world conditions must have its origin within the communities. Any attempt at solution of the community problem must give some consideration to the fundamental elements which exist in every community, and to the underlying principles, and ways of life and thought, upon which community life is based. The community is, in its essence, a number of people living and working more or less closely together, sharing common rights, privileges, conveniences, and comforts, which would be impossible for the individual to obtain for himself by his own efforts alone, or in any other way than by the mutual exchange of persona! services and resources. In this way, men have increased the returns from their labour and commerce, have raised the standard of their living, with better social, educational, and recreational facilities, and enjoy a greater personal security.

Jan 1, 1943

By N. Hwang

There has been increasing interest in the use of robotic machines, and several prototype robotic machines have been developed to automate the grit-blasting process for the purpose of steel bridge maintenance. To utilize such a robotic grit-blast machine effectively, the first consideration is automating the determination of the rust surface area to blast, on the basis of standards of practice, in a rapid manner. This study aims to propose a method to rapidly and accurately determine the rust surface area on steel bridges to blast, with consideration for the standards of practice, from images acquired via a blasting machine. The first step is to perform a color space conversion to transform the input image from a red/green/blue (RGB) color space to a hue/saturation/intensity (HSI) color space. The next step is to detect the presence of rust, using pixel-level classification via the C4.5 decision tree algorithm. Then it is necessary to confirm the blasting area by verifying whether the rust detection result satisfies the specified criteria on the basis of standards of practice. The proposed method was validated on 39 test images with various characteristics with respect to the degree of rusting and rust distribution type. The experimental results showed that the average accuracy rate of rust area classification was about 97.63%, and the success rate of the final decision of blasting area determination was 100.00% for 39 test examples. The whole processing time took an average of only 0.86 seconds per image. The preliminary results demonstrated that the proposed method not only determined whether rust was present in an image and the amount of rust but also indicated whether blasting was necessary, and, if necessary, it rapidly specified the rust surface area that should be blasted on the basis of standards of practice. The proposed method could be successfully incorporated into a robotic grit-blast machine.

Aug 1, 2013

By S. Beskri, N. Geoffroy

When metallurgical plants are designed, a lot of consideration is almost always given to material selection and possible damage mechanisms. Materials engineers are generally involved and will strive to select optimal alloys or refractories for the design conditions. Once in operation however, things often change. Equipment is overstressed to increase production, corrosive leaks are not always promptly addressed, proper welding procedures are disregarded, etc. This paper describes various cases from the mining and metals industry where serious mishaps, associated consequences, and costs could have been avoided if simple and proactive steps had been taken. It also presents a strategy, based on safety reviews, to help predict and prevent damage to critical pieces of equipment.

Jan 1, 2015

By T. A. Lloyd

"This paper indicates the extent to which Canadian coal mine operators have taken advantage of developments in the science and technology of coal that would allow them to better satisfy changing market demands through improving the properties of their products. At some mines, no attempt is made to alter the coal from its as-mined condition, but at most mines grading into various size ranges and hand-cleaning of lump sizes is undertaken.Over-all, Canada Jags behind most of the other major world coal producers in the proportion of its coals being processed in wash plants. To some extent, this is due to the fact that a high proportion of the coal production satisfies market demands without such treatment. On the other hand, a few of the coal mines in Canada, which produce about 25 per cent of the nation's total coal output, have in operation some of the most modern coal beneficiating equipment available, including jigs, flotation cells, water cyclones, centrifuges, disc filters and thermal dryers."

Jan 1, 1968

By R. M. S. Häggblad

The article deals with stabilisation and regeneration of Ce02 and Ce02/Zr02 based Pt water gas shift catalysts, subject to high initial deactivation. The reaction gas species effect on the catalyst deactivation was investigated by H2-TPR. Activity measurements enabled the effect of different promoters, some added to the Ce02 based catalysts and some to the Ce02/Zr02 based Pt catalysts, to be investigated. The catalysts were also characterised by BET and CO-TPR. Deactivated catalysts activity was restored by using various regeneration methods. Of the two selected carriers the Ce02/Zr02 based Pt catalyst showed the highest resilience to deactivation. For the two different carriers, Ce02 and Ce02/Zr02, Wand Re were the best promoters when the catalyst was subject to deactivation. Experiments with Hr TPR indicate a fast initial change in the platinum oxides concentration and composition. The CO-TPR was used to make conclusions about the various regeneration effects of water and oxygen on the catalyst. Finally it is suggested that not one deactivation mechanism is possible and which mechanism that dominates is dependant on the catalyst and the reaction gas composition.

Jan 1, 2005

By David Burchell

Duckbill mining is probably the simplest method of loading coal mechanically at the face in underground mines. It is a means of reducing the amount of physical labour required to produce a ton of coal. In effect, it is merely shaker conveyor mining brought up to date with the addition of a self-loading head or 'duckbill' on the end of the conveyor line. Any mechanical device used to load coal is a means of supplanting the human muscles as the medium for getting the coal off the floor into the transportation equipment. There can be no argument with the conclusion that a man can lift so much and no more. He can load more tons of coal on a low conveyor, because the lift is less, than he can in a pit car two, three, or even four feet high. Thus it follows that, if the lifting operation is entirely eliminated, the man should be able to produce even more coal. A mechanical operation is essentially a multiplication of physical strength. Although there are various ways in which coal can be loaded at the face by mechanical means, there is, perhaps, none more adaptable than shakers equipped with duckbills. This is particularly true for thin seams and in mines having heavy, tender top conditions which require close timbering. However, as we are discussing duckbill mining, we will make no further reference to any other type of equipment. The first, and to date the only, mine in eastern Canada to adopt a system of mechanical loading at the face is the Franklin mine of the Bras d'Or Coal Company, Ltd., at Bras d'Or, N.S. An experimental Goodman shaker conveyor with a self-loading head, or duckbill, was installed in this mine in 1940. Since that time other units have been placed in operation so that, today, this mine is completely mechanized. The method of operation 1s room-and-pillar. The operation is carried on in a 42-in. seam, which lies 420 feet beneath the Sydney Main or Harbour seam in the Sydney Mines basin. The slopes bear N.25 30'E., dip 10 per cent seaward, and are about 6,000 feet in length. The physical conditions of this seam do not make it particularly adaptable for complete mechanization as it contains a large amount of foreign material, such as clay intrusions or wash-outs and iron pyrites. These clay intrusions, known locally as 'troubles', vary in thickness from a few inches to as thick as eighteen feet and usually replace the coal to the full height of the seam.

Jan 1, 1947

By P. Mundell, R. Torbin

"There are many physical and operational obstacles in pipelines that make the passage of inspection robots impossible including:•,Small radius bends•,Low operating pressure•,Plug valves•,Large changes in pipe size•,No permanent access to the pipeline.The inspection of unpiggable pipelines requires the marriage of a highly agile robotic platform with NDE sensor technology operating as an integrated system. Foster-Miller and GE/PII are developing a robot that is essentially a battery powered, train-like platform. Both front and rear tractors propel the train in either the downstream or upstream direction. Like a train, the platform includes additional ""cars"" to carry the required payloads. The cars are used for various purposes including the NDE sensor module(s), the power supply, and data acquisition/storage components. The robot is designed with a slender aspect ratio and the ability to change shape as required by the physical obstacle presenting itself. The MFL sensor module must also morph itself through the physical obstacles, and thus, will require some level of segmentation. The segmented MFL magnetizers and transformable sensor module represent a major advance in the science of sensor technology and pipeline inspection."

Jan 1, 2005

By B. W. Clyburn

"Coals from the Corporation's Lingan and No. 26 mines are classified as high-volatile A bituminous, with a very low inherent ash and containing all essential properties to provide metallurgical coal, with the exception of a high sulphur content. Only through proper cleaning at low specific gravity can the pyritic sulphur fraction of the coal be liberated to an extent where final sulphur meets coking standards. This first section of the paper deals with the operation of a Dutch State Mines heavy-media cyclone circuit to achieve an actual separation in the region of 1.30 specific gravity. A discussion of the parameter of control which must be applied along with an appraisal of the results obtained is included in the paper.Introduction Very high fluidity and unusually low ash are the outstanding characteristics of coal from Devco's mines in the Harbour seam of the Sydney coal field. However, sulphur content, mainly pyritic, ranges from 1 to 2.50Jo. To obtain the low and consistent sulphur level required in metallurgical coking coals, preparation at low specific gravity is required. Metallurgical coke is used as the fuel in an iron blast furnace. Its sulphur content largely determines the quantity of slag required to remove it and therefore influences furnace productivity and unit costs. Typical data on the various coal properties of importance in the production of coke are included in Table 1."

Jan 1, 1985

By M. Maldonado, P. Olivares

"A submersible sensor for real-time gas holdup measurement in the collection zone of industrial flotation machines is introduced. The working principle is based on the generation and measurement of a pulp flow using a gas-exclusion cell immersed in the aerated slurry. The gas exclusion cell consists of a variable-area open vertical tube designed to be filled only with pulp by preventing gas bubbles entrance. The higher density of the fluid column within the cell generates a downward flow of pulp; the rate of this flow is proportional to the gas holdup outside the cell. The gas holdup measurement is achieved by tracking the velocity of the pulp flow leaving the gas-exclusion cell, using a magnetic flowmeter. Construction details of a prototype and its testing in two- and three-phases are discussed.INTRODUCTIONFlotation process optimization consists of finding and maintaining operating conditions that maximize flotation performance measured in terms of recovery and grade. The selective separation of mineral particles proceeds in two interactive zones where different and simultaneous phenomena take place: in the collection zone, the valuable particles are separated by collection on the surface of bubbles, while in the froth zone, the bubble-particle aggregates are gathered, drained to remove entrained particles, and taken into the concentrate stream. The cell overall performance, which can be determined from proper stream sampling, is a function of the recoveries in the individual zones. These zone recoveries cannot be independently measured nor calculated from operating variables. Progress in the assessment of these recoveries has been slow because on-line and reliable sensors to measure properties of the drastically different dispersions existing in both zones are not available.In the case of the collection zone, it has been demonstrated that the recovery of hydrophobic particles on the surface of bubbles, considered as a process with first-order kinetics, correlates with the bubble surface area flux (Finch et al., 2000; Hernandez, et al., 2003; Lopez-Saucedo et al., 2012). Bubble surface area flux (bubble area generated per unit time and cell cross-sectional area), is a variable affected by gas flow rate, bubble size distribution, and frother type and concentration. Gas holdup (volumetric fraction of gas dispersed in the slurry) is also affected by the same variables, and as such, carries information on the interacting variables that define the performance of the process. Therefore, a correlation between gas holdup and bubble surface area flux was expected and demonstrated (Finch et al, 2000), and since gas holdup is easier to measure as no bubble size is required, it has the potential to be the basis of a cell control and optimization strategy if a continuous sensor is available."

Jan 1, 2016

By Gerald Blackmore

This paper discusses the present state and future trends within the coal industry, and then goes into the reasoning behind these planned trends. Such factors as marketing, costs, new mining techniques and machinery, and manpower and human resources are considered. Finally, the author refers to the effect that these trends will have on the coal industry of Cape Breton.

Jan 1, 1968

By P. G. Thornhill

EARLY in 1951, Falconbridge undertook a research program aimed at the development of a sulphate roasting process for the recovery of the non-ferrous rnetals from the nickeliferous pyrrhotite fraction of Falconbridge ore, in order to reduce the tonnage of iron entering the srnelter. Such a method, it was hoped, would permit a high recovery of the nickel from pyrrhotite otherwise entering the smelter feed, thus not only raising the grade of the latter and reducing its iron content, but also providing an iron oxide residue useful as a source of by-product iron ore. At an early stage in the exploratory laboratory test work it was found that the degree to which the nickel could be solubilized by the sulphating roasting treatment was limited by particle size and the ex-tent to which the pyrrhotite concentrates were freed of the nickel occurring as physically separable pentlandite, a mineral relatively difficult to roast. ( 1) Thus the program

Jan 1, 1961

By Andrew Dobson, Cheryl Allen, Enrique Acuña

"Totten Mine return air raise was designed with two parallel fans equipped with silencers to reduce the noise emitted from the outlets into the environment. As development and production of the mine progressed through the past years, the silencer system needed to be upgraded, and additional maintenance strategies have been necessary to meet the regulatory noise limits enforced by the province of Ontario. The current mine plan will require the fans to reach the upper limit of their capacity by Q1 2019. To achieve this operational target, additional silencing capability has been required and Totten Mine has explored alternatives to further extend the noise silencing capacity available considering the current constraints at the mine site. The alternatives included a new silencer baffle design and a new layout that have allowed doubling the length of the silencer system. Using acoustic measurement data collected on several occasions, this paper presents and discusses the performance of the various silencing systems which have been installed on the return air fans at Totten Mine.INTRODUCTION Vale Canada Limited’s Totten Mine is a base metal, underground mine extracting nickel and copper, situated in the Sudbury Basin of Ontario. The mine initiated operations at the end of 2013, and is equipped with two main return air fans and two main fresh air fans located on surface. Both fresh air and return air fans are set in a parallel arrangement to operate as integrated units and are equipped with variable frequency drives (VFDs) to allow for the remote modification of their operating set point, usually between 600 to 880 rpm, depending on the mine’s requirements. The main return air raise (RAR) fans are also equipped with dissipative baffle silencers to attenuate the noise emitted to the environment. Approximately four years ago, acoustical measurements conducted to verify compliance with the applicable regulatory criteria, and respond to noise concerns from neighboring residents, concluded that the sound emissions of the main return air raise exceeded the noise design parameters. The acoustic tones of the fans were audible offsite, at a residential location, approximately 9 km northeast of the mine site. The elevated sound levels and offsite audibility was due to degradation of the original discharge silencers from moisture and particulate being drawn from underground workings and passing through the silencer baffles. The audibility was also due to an outlet directivity pattern which directed noise towards the residential location."

Jan 1, 2019

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 J. S. Vanderploeg

I WILL begin this presentation by citing the annual per capita use of copper in Canada. This is best calculated by taking refinery domestic sales, plus imports of the products of foreign fabricating mills (very little refinery copper is imported), and deducting the exports of Canadian mills. No attempt has been made to estimate the copper content of imports or exports of machinery, motors, etc., but the trade balance here is probably against Canada. In any event, we find that, though varying somewhat since the war, the estimated yearly per capita figure has reached a high of 18 pounds. This is practically on a par with the United States. The rest of the world uses an average of about 2 pounds per capita, yearly, though this includes some countries, such as Sweden, Germany and England, which consume much better than average quantities. It looks, therefore, as if the Canadian copper industry has not (as has been generally charged) been asleep after all.

Jan 1, 1962