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By K. K. Dehn

This study focused on determining the stability of thin shotcrete fill fences at a hard rock mine in northwestern Ontario during increased pour rates of paste backfill. Determination of the stability of the fence is needed for both personnel safety and to avoid failure of a fence. Failure of a fill fence during backfill activities would have severe impacts on production and potential hazards to nearby workers. Approved fill fences at the mine are a slender design of 10.5 centimeters of shotcrete applied to a rebar framework with burlap lined ?bedspring? backing. Approved mine standards dictate that fill rates may not exceed 1.5 meters of paste depth per 10-hour shift when pouring behind a flat fill fence. To decrease the backfill cycle time the study looked at fence stability during increased pour rates of 2.5 meters paste depth poured within a 10-hour shift. An instrumentation design was developed including pressure cells, strain gauges, and tilt-meters that were built into experimental fences to observe the effects of increased pour rates on lateral wall pressures, strain development in the rebar and shotcrete reinforcement, and physical deformation patterns along the face of the fence. The data was analyzed for overall stability.

May 1, 2007

By Rita Aiello, Stan Mack, Peter Werth, Joseph McCarney, Jozef Stachulak

"Johnson Matthey has developed the first diesel particulate filter (DPF) for underground mining that controls particulate matter (PM) at the same time as maintaining emissions of NO2 at or below engine baseline levels. DPF technology is critical for controlling PM which is classified as a carcinogen, but passively regenerating systems rely on the use of oxidation catalysts that can potentially increase NO2 emissions. This paper reviews the development of low-NO2 PM control technology and the results from testing this technology underground on diesel mining equipment. KEYWORDS Decomposition catalyst, Diesel particulate filter (DPF), Diesel particulate matter, Mining Continuously Regenerating Trap (CRT®), NO2, SCR INTRODUCTION The introduction of diesel particulate filter (DPF) technology on heavy duty diesel (HDD) engines has been an important step towards addressing the clean air and health concerns for mining companies. Control of diesel particulate matter (PM) emitted from diesel engines is already being implemented for on- and off-road vehicles, and similar legislation is being prepared for mining equipment. In addition to PM, the diesel emission control strategies (DECS) also reduce carbon monoxide (CO) and hydrocarbons (HC). Some DECS control oxides of nitrogen, or NOx, which is composed of NO and NO2. Johnson Matthey has led the development of emission control technologies for diesel engines for almost 30 years. Over the last ten years alone JM has supplied over 3 million Continuously Regenerating Trap (CRT®) DPF systems for on-road vehicles, and over 200,000 systems for off-road vehicles. The patented CRT technology combines a diesel oxidation catalyst (DOC) with a DPF to effectively trap harmful PM from diesel exhaust, while removing CO and HC. The DOC converts part of the engine NOx to NO2, which reacts with the trapped soot to regenerate the filter. As engines become more fuel efficient, less waste heat enters the exhaust. This can be a disadvantage for after-treatment systems as it leads to lower catalyst operating temperatures. The CRT system regenerates passively, without addition of heat, at temperatures that are typical of diesel engine exhaust. JM recently launched the Mining CRT system which integrates CRT technology with NO2 abatement to reduce PM and tailpipe NO2 from underground diesel mining equipment. This is the first technology proven to control both PM and NO2 emissions for a cleaner, healthier working environment. The Mining CRT is also cost-effective compared to other technologies."

Jan 1, 2019

By M. Vallée

Several reviews of mineral project performance in the past 35 years indicate a pattern of occasional, but recurrent, mining project failures due to shortcomings in geological information and estimation, mineral processing and metallurgical testing, feasibility study objectives and requirements, and project start-up methods. A commitment to quality assurance and continuous improvement methods and to obtaining “ENOUGH DATA, OF APPROPRIATE QUALITY” is essential. Recent international and Canadian proposals for mineral resource and ore reserve definitions have taken a nonprescriptive stance that will undermine the formulation of requirements, guidelines and industry standards for efficient deposit delineation and estimation, and for the determination of project feasibility. To help reduce problems, every feasibility study supporting a mine development and production decision should be based on objectives and methods adequate to reach completion targets similar to the bankers’, as a good business target for a profitable project. In a resource/reserve system, the use of reserve should be restricted to a project that meets required technical, economic and legal feasibility requirements for successful project implementation, and the definitions of these categories should provide explicit limits. Current shortcomings will limit the ability of the Qualified Person to provide “adequate professional practice,” fulfill his/her professional responsibilities to his employer or client and provide adequate information to the investing public. We must take advantage of present opportunities for Setting New Standards for the new Millennium.

Jan 1, 2000

By H. C. Gunning

Introduction The invitation to contribute a discussion on some of the broader features of the mineral deposits of our Cordillera seemed acceptable enough when presented several months ago. More mature consideration has impressed upon me the difficulty of making any constructive or very helpful contribution in the short time available and with my limited inspiration. Dr. Lang deserves our real gratitude for his general paper of nineteen pages at the beginning of the Volume. Into it, with the help of two diagrams and seven tabular summaries, he has packed a lot of useful information and has analyzed along several lines the data of the Volume's twenty-eight detailed papers on our mines and camps. He has added additional facts from his own knowledge of the region. I am sure that, like myself and the whole fraternity, he feels especially grateful to the eleven company geologists who found time to contribute detailed descriptions of mines they have studied. The Regional Situation With the Jubilee Volume and two recent publications of great value from the Geological Survey, we are more up-to-date on Cordilleran geology than we have ever been. But I would like to emphasize that we still have but fragmentary information. Brief study of G.S.C. Map 932A will illustrate this. Our knowledge of the Rocky mountains is limited to two narrow sections along the main railway lines, a somewhat larger area from the border north along the Mesozoic coal-bearing basins, and some reconnaissance along Peace river and the Alaska highway. There is some additional information on old maps, particularly those by G. M. Dawson, but it is very much of the 'exploratory' type. The other mapped areas are chiefly in the accessible region south of 'fifty-one', in the central part adjacent to and spreading north, recently, from the Canadian National railway, and along the edges of the Coast Range.

Jan 1, 1950

By J. G. Manchuk, M. Thurston

"The degree of uncertainty associated with a natural diamond resource is important to quantify from the time of discovery through the production lifetime. Data collection occurs during the discovery, exploration, delineation, and production or recovery phases. Quantifying the relationship between data and uncertainty is an important component of project valuation. The value of data is measured as their potential to reduce uncertainty if they are collected. A method is developed using Monte Carlo simulation for predicting resource uncertainty and valuing data during critical phases of development, particularly discovery and exploration. The technique is applied to diamond pipe deposits.RÉSUMÉ Il est important de quantifier le degré d’incertitude associé à une ressource diamantifère naturelle, depuis le moment de sa découverte et durant toute la durée de l’exploitation. La collecte de données se fait durant les phases de découverte, d’exploration, de délimitation, et de production ou de récupération. La quantification de la relation entre les données et l’incertitude est une composante importante de l’évaluation du projet. La valeur des données est mesurée en tant que leur potentiel à réduire l’incertitude si elles sont recueillies. Une méthode a été développée qui utilise la simulation de Monte Carlo pour prédire l’incertitude de la ressource et évaluer les données durant les phases critiques du développement, surtout celles de la découverte et de l’exploration. La technique est appliquée à des gisements de cheminées diamantifères."

Jan 1, 2015

By G. W. Poling

Sedimentation behaviour of siliceous mill tailings derived from a magnetite-chalcopyrite ore in fresh water, fresh water - sea water mixtures and full-salinity sea waters are compared. Results of batch settling tests are presented in the form of settling curves and solids flux curves. The addition of a few per cent of sea water markedly enhanced the zone sedimentation rate due to particle agglomeration caused by a reduction in zeta potential of the suspended solids. The presence of a small amount of residual, previously magnetized magnetite in the tailings also enhanced agglomeration and sedimentation. The significance of these results to submarine disposal of mill tailings is discussed.

Jan 1, 1973

By B. K. Mishra, Avijit Biswal, B. C. Tripathy, Abhijeet Singh, K. Sanjay, T. Subbaiah

We studied theeffect of anode substrates such as pure lead (Pb), lead antimony (Pb-Sb), and lead-silver (Pb-Ag) on the structural and electrochemical properties of electrolytic manganese dioxide (EMD). X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and chemical analyses were used to determine the structural and chemical characteristics of the EMD samples. The charge-discharge profile was studied in 9 M KOH using a galvanostatic charge-discharge unit. In all the substrates the current efficiencies were more than 99% except with Pb-Sb where it was 90%. Results revealed the nature of the substrate strongly affected the morphology of the deposited material which in turn affected the electrochemical properties of the EMD samples. XRD analyses revealed that the nature of the anode did not affect the crystal structure of the deposited EMD and all the samples were predominantly ?-MnO2, which is electrochemically active for energy storage applications. The EMD deposited on lead substrate showed superior discharge capacity of 245 mAhg-1 when compared with other substrates.

Jan 1, 2014

By E P. Graham

Orebodies occur in an infinite variety of grades, shapes and sizes, and take many millions of years to grow. When extraction starts there is only one possible end -the mine sooner or later will run out of ore and shut down. If the mineral industry is to supply the ever increasing demands of modern civilizations, more and more metals must be found and mined. This will require a never-ending search for ore, and the development of every economic body, large or small. To justify the mining of a small orebody, it first of all must pay its way. If the size of the burden imposed by the capital cost estimates is not carefully worked out, an otherwise promising situation could be killed. The very nature of mining, as a transient industry, re-leases a steady stream of good used equipment, and the trained personnel to install and operate it. All manner of plans and layouts, which can be utilized at a new property, are available. Working these and other economies into the estimates will sometimes make enough difference to give a prospect the green light.

Jan 1, 1964

By D. J. King

The development in recent years of a fluidized bed system for use as a counter-current solid ion exchange loading contactor for the purification and concentration of uranium from leach liquors has had a major impact on the design of uranium extraction plants. The main object of this paper is to describe many of the variations that can be applied to the design of uranium extraction plants arising from the use of a fluidized bed loading contactor with a view to providing a guide for the development of a flowsheet for a new uranium extraction plant. The paper has been devoted primarily to the consideration of conventional uranium extraction plants in which a ground ore is leached in mechanically or air agitated tanks. The effect of the use of a fluidized bed loading contactor on each of the plant sections from leach to uranium purification and concentration has been considered. In order to describe most effectively the impact of using a fluidized bed solid ion exchange loading contactor, its use has been compared with the performance that can be achieved with the most common alternative purification processes. The comparisons are made largely on a technical basis, but the effect on the capital and operating costs of the different uranium extraction flowsheets are described qualitatively. In making these comparisons, consideration is given to the effect on the size, number and materials of construction of equipment items and how the quantity and composition of the liquid effluents can be controlled to reduce the environmental problems arising from the disposal of these effluents. The paper also discusses some of the factors that should be taken into consideration in the design of a fluidized bed loading contactor and describes various designs of the elution section that can be used in conjunction with the loading contactor.

Jan 1, 1979

By Greg Baiden

Telerobotics focused on mining is currently being introduced into production systems around the world. Mining companies in Canada, Sweden, South Africa and Australia have tended to lead the international charge to this form of technology for mining. While this introduction is taking place a few basic questions have yet to be answered. How many machines can a single operator run? How many types of machines can a single operator run? A new Canadian Research Chair in Robotics and Mine Automation has been established at Laurentian University. This chair will investigate these questions and many more through a series of experiments in a newly established telerobotics laboratory that connects Laurentian teleoperation workstations to model mining machines at Cambrian college?s eDome. The laboratory will support many experiments allowing researchers to physically run multiple robot scenarios differing the numbers and types of machines at one/quarter scale. Further experiments are being designed to investigate the potential for managing time delays in telerobotics. This paper describes the laboratory, experiments and some preliminary results.

May 1, 2003

By R. S. Boorman, H. G. Ansell

"Poor separation of lead from a copper concentrate of a major base metal producer was thought to have resulted from copper (0.2-0.4%) in the galena which caused it to float with chalcopyrite. No inclusions of copper mineral were detected which could account for the flotation of galena. The tendency for copper-bearing galena to float with chalcopyrite was confirmed by Hallimond-tube experiments in which the floatability of copper-doped synthetic galena (0.1-0.4% Cu) was approximately four times as high as copper-free galena. The difference in the cell edge (5.9338 ± 0.0003 A, Cudoped galena; 5.9361 ± 0.0002 A, Cu-free galena) indicated that the copper was lattice-bound and did not occur as submicroscopic mineral inclusions."

Jan 1, 1973

By D. E. Keeley

Introduction Gunite is a mixture of sand and cement applied to any surface by being shot by compressed air through a nozzle, where it is wetted just before leaving the orifice. The mixture is transported through a hose from a machine called a 'cement-gun'(l). Guniting of rock surfaces has been standard practice at the Mcintyre Porcupine Mines, Limited, for several years. Where used on walls and backs of cross-cuts; shaft stations, and other rock openings, as an air seal, gunite has eliminated the necessity of constant scaling to keep rock from falling from these places, and, under worse conditions, it has been used in place of timber supports. This has been of definite help in reducing costs, promoting safety, and minimizing fire hazards. During the past year guniting has been quite extensively used here in the rock head-works of the new internal shaft, No. 12, sunk from the 3,875-foot level. Gunite is at present being applied to the stations of that shaft well below a mile from the surface. This paper describes the method of guniting as carried out at the McIntyre, and illustrates how, by the adoption of this process, mining problems connected with scaling and loose ground have been completely solved. It is hoped that the information presented may stimulate discussion and assist in the use of gunite in this and other mines. The guniting method of applying cement was first developed by Carl E. Akeley (2), Curator of the Field Museum, Chicago, in 1907, and was exhibited in New York at the Cement Show in 1910. The museum was located in one of the old World's Fair buildings, built of roughcast and in bad repair. Mr. Akeley, who was a man of inventive nature, set about devising means of applying cement to repair the walls. The cement-gun was the result. Mr. Akeley was a taxidermist of note, a sculptor, and also the inventor of the Akeley camera. In his work, he was in the habit of using fast setting materials to build up foundations for statues, etc.

Jan 1, 1934

We describe a new method of characterising the effect of dissolved materials on the rate of coalescence of bubbles in aqueous media. Single bubbles were allowed to rise to meet the surface of an aqueous solution, and the time of persistence between arrival and bursting of bubble was measured as a function of solute concentration. A laser beam was placed just above the surface of the liquid, with a detector in the light path, so that any disturbance at the surface could be seen as a break in the beam. The arrival of a bubble at the surface could be detected from the behaviour of the trace on an oscilloscope, and when the bubble broke, another significant change in the signal could easily be seen. The time between disruptions was reported as the persistence time. The effect of a homologous series of n-alcohols (C1 to C8) on the persistence time was measured, in aqueous solution. It was found that with increasing concentration of a particular solute, the persistence time increased up to a point, and then declined. However the magnitude of the persistence time was found to increase with increasing numbers of carbon atoms in the molecule. Bubbles of 1, 2 and 3 mm diameter were used. Persistence time increased with increasing bubble diameter, the maximum values observed being of order 100 secs. For a given solute, the persistence (drainage) time increased with increasing bubble diameter. The concentration Cmax at which the maximum persistence time was observed, was found to be independent of the bubble size. It decreased uniformly as the carbon number increased, and was well correlated by the function y1/2 (dy /dc) -2 I dc)-2 . There was no apparent correlation with the surface excess at maximum persistence time.

Jan 1, 2006

By L. Shasko

Deliberative mapping is a method of public engagement designed to bring citizens and specialists together to inform policy decisions in conflict-laden areas of science and technology (Stirling and Davies 2004a). Citizens and specialists participate in the process both separately and together. A deliberative mapping study was held in Regina, Saskatchewan in October and November of 2019. Participants in the study assessed options for reducing greenhouse gas emissions in small, remote or off-grid communities, including assessing the role of small modular nuclear reactors (SMRs) in climate change mitigation. Deliberative mapping is designed to facilitate direct, two-way conversations between citizens and specialists through both formal and informal discussions. The relationship building component of this process may increase trust. Public consultation processes that lack two-way dialogue or are seen as obligatory rather than meaningful can worsen public opposition or lead to negative public perceptions. Public education alone is not enough to change public opinion. Providing people with more information on topics they already hold opinions on can work to reaffirm previously held biases, but building relationships can provide new pathways to overcome divisions and turn close-mindedness into open-mindedness.

Jan 1, 2020

By D. W. Euler, D. G. Brophey

"In an attempt to address the issue of rising labour costs, and to improve productivity, a laser-based system to guide underground LHDs and trucks has been developed. This comprehensive system is known as the Opti-Trak system.Essentially, the vehicle is equipped with front and rear-mounted lasers which scan a reference strip mounted on the drift back. The vehicle follows this reference strip and in addition, based on reflective bar codes mounted beside the reference strip, initiates certain functions (i.e. dump cycle, speed change, brake check, etc.). Any programming that is drift-specific is handled by the positioning of the reference strips and bar codes. Consequently, the vehicle can easily travel to many different haulageways or branches, providing the reference strip and bar codes are in place.The advantages of this system are an immediate elimination of haulage operator costs and an increase in available hauling time to 7 hours out of an 8-hour shift as compared to the typical 5Y2 out of 8 hours that a manned haulage system offers.This paper describes the Opti-Trak system and the benefits to be realized from automation of mine haulage requirements."

Jan 1, 1994

By A. M. Bell

General Summary THIS paper attempts to describe in a preliminary and general manner the nature of certain copper discoveries now being developed by Gaspe Copper Mines, Limited, in Holland township, in the interior of the Gaspe peninsula. Some copper mineralization appears to have been known here at the time of the earliest French explorations, was rediscovered in 1921, and has been under intermittent development by Noranda Mines since 1938. In the last two years discoveries have enhanced the picture so that the deposit now promises to develop into one of the important Canadian copper producers. As ideas are constantly changing with continuing development, any picture given now is very partial and tentative and must be subject to future revision. The nature of these copper occurrences differs from others known in eastern America. In many respects they have unique features but they are most closely akin to some copper deposits found away from the intrusive rocks in the porphyry copper districts of the western United States. The most important orebodies are replacement deposits in a limestone horizon in which the ore gangue is converted to skarn. These lie at considerable distances from any known intrusive but seem to have been derived from a buried stock of granite that intrudes the sedimentary rocks of Lower Devonian age. This intrusive has produced alteration effects in the overlying rocks that may afford a key to locating other ore areas in the Peninsula.

Jan 1, 1951

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

By M. R. Khalesi, S. Bellec, C. Bazin, D. Hodouin

Batch grinding tests conducted on a gold ore indicated that gold is not randomly distributed within the size fractions of the ground ore. Since gold leaching performances were found to be dependent of the size of the gold carrying particles an integrated gold ore grinding-leaching simulator should incorporate a method to predict the gold size distribution of a ground ore. The paper describes the results obtained from batch grinding tests showing the non random distribution of gold within the size intervals of a ground ore and the initial developments of a grinding model to predict the gold size distribution in a batch grinding product.

Jan 1, 2011

By S. Bhattacharjee

"Rock failure process is generally recorded or measured using conventional sensors like strain gauges, seismic, micro-seismic, acoustic, electromagnetic and other techniques. The above sensors are either to be pasted on the surface of the rock sample or placed very near to it to capture the response of the sample with the increment of load. This requires precise tools to cut or polish the locations where sensors are to be placed. Moreover, deformation or acoustic or micro-seismic activities are recorded only at the locations where sensors are pasted.Recent development in Digital Image Correlation (DIC) technique has shown promise to measure deformation / strain at every location of the surface of a sample. In DIC, two images (reference and deformed) are taken within a small time interval of the same object are compared to estimate the change in reflectance as a function of displacement, velocity or rate of strain at each pixel while the object is undergoing through a loading process. In this study, extended digital image correlation (X-DIC) technique has been implemented using 4-noded quadrilateral elements with a discontinuity surface in the deformed image. The continuous and enriched displacements are estimated at each node.The X-DIC method is verified using numerically generated images. The study has been further extended to evaluate the performance of X-DIC method on deformation analysis of experimental samples under uni-axial loading condition. The results of this study show that X-DIC method is an effective tool for determination of displacements of the entire surface of a rock sample having a discrete crack or discontinuity in a non-contact manner. This method demonstrates the applicability to investigate rock failure mechanism for the entire sample in a laboratory set up as well as monitoring of pillar failure mechanism in underground mines."

Jan 1, 2015

This paper describes basic parameters, such as surface forces and film elasticity, affecting the stability of foams (two-phase froths). We used the thin film pressure balance (TFPB) technique to measure the surface forces in foam films stabilized with various frothers such as pentanol, octanol, methyl isobutyl carbinol (MIBC), and polypropylene glycol (PPG). The results were compared with the foam stabilities measured experimentally and the film elasticities calculated using a new model developed by Wang and Yoon (2006). It was found that at low electrolyte (NaCI) concentrations foam stability is controlled by both film elasticity and surface forces (or disjoining pressure), the relative contributions from each changing with frother type and concentration. Further, the kinetics of film thinning was studied at a high electrolyte concentration. The results obtained in the present work showed that the major role of a frother is to decrease the hydrophobic force rather than to increase the film elasticity. This conclusion is drawn from the observation that at the typical frother (MIBC) concentrations employed in flotation, frother additions cause sharp decreases in hydrophobic force while causing relatively little changes in film elasticity.

Jan 1, 2006