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By W. C. Whittaker

Introduction When one thinks of a coal stripping deposit, the picture that usually comes to mind is that of a more or less flat seam from two to twenty feet in thickness overlain by ten to fifty feet of overburden, in suitable ratio for economic operation. This is the usual type of stripping deposit and is quite a common occurrence in various parts of the prairie provinces. Rather unusual types of coal stripping deposits are being presently worked as open-cut mines by Sterling Collieries, Limited, and the Co al Valley Mining Company, Limited, at Miles 47 and 48 on the Alberta Coal Branch, some 150 miles south west of Edmonton. These deposits are of interest chiefly because they represent turned-up and greatly thickened sections of the Mynheer seam, and as such they present their own problems, peculiar to the commercial exploitation of a seam of this type. The area in which these deposits occur was originally owned by the Pacific Pass Collieries, whose operations, however, were confined to under-ground mining at Lovett, some eight miles to the southeast. It was not until l918 that the value of these deposits was realized, when the Company now known as Sterling Collieries, Limited, opened their pit at Mile 47. At the inception of the work, coal was loaded directly into the railway cars by men using wheelbarrows. In 1920, a tipple was built, after which the coal was loaded by steam shovel into mine cars, hauled by steam dinkeys, and loaded over the tipple into railway cars. In 1922, the Coal Valley Mining Company entered the field at Mile 48, with an entirely mechanical equipment, and at the present rime these two are the only stripping properties in Alberta using mechanical equipment both for the removal of overburden and the loading of the coal. These Companies have operated continuously since that time, and have to date mined and shipped 4,000,000 tons of coal, and moved some 5,255,000 cubic yards of stripping. The present annual coal output for the two mines is about 240,000 tons.

Jan 1, 1935

By T. Johnson, K. Lambrych, D. Kelley

Materials for construction of equipment used in hydrometallurgical plants are selected based on a combination of their ability to perform as required in aggressive process environments as well as their cost. As a material of construction, fiber reinforced plastic (FRP) has been shown to provide equal if not improved durability relative to alternative materials such as corrosion resistant alloys at a considerably lower cost. This is particularly true in the case of equipment used in acid leaching processes for copper, cobalt, nickel and rare earth elements. The selection and extensive use of FRP over alloys in new hydromet plant construction in North and South America illustrates this advantage of FRP effectively. This paper will compare corrosion performance and cost of plant equipment fabricated with stainless steel alloys and FRP made with Epoxy Vinyl Ester thermoset resins. Real world case histories for FRP piping, storage tanks, extraction vessels, and electrowinning cells combined with laboratory based corrosion studies will be reviewed to demonstrate how FRP materials are selected for hydrometallurgical equipment.

Jan 1, 2015

By A. G. Scobie

THE research laboratory of this Company was recently faced with the problem of determining trace amounts of tungsten in a series of classifier sands. A spectrographie survey revealed the feasibility of using this instrument in the final evaluation, but a check of the common methods in use for the isolation of tungsten (3, 4) showed these methods to give incomplete separation for trace amounts. An investigation into the possibility of modifying these procedures, or developing others, was thus indicated. ASSAY PROCEDURE Weigh 10 grams of 200-mesh ore or concentrate into a 400-ml. beaker, wet the sample well with about 20 ml. of water, and add 100 ml. of hydrochloric acid. Cover, digest at 60° to 70° C. for about 1 hour, and then boil down to approximately 25 ml. Cool, add 25 ml. of hydrochloric acid and 10 ml. of nitric acid, and again boil to former volume. Add 20-ml. portions of nitric acid with successive boiling clown until chemical action is complete. Then add 20-ml. portions of hydrochloric acid until all nitric acid is removed. Take nearly to dryness on a law-temperature hot plate, but do not bake. Take up in 10 ml. of hydrochloric acid and 20 ml. of water and heat on a law-temperature hot plate until all iron goes into solution. Dilute to 200 ml. and heat to just below boiling. Stir in pulp of about half of a No. 41 Whatman filter paper (12.5-cm.) and continue digestion on plate with occasional stirring for 15 to 20 minutes.

Jan 1, 1943

By Grant L. Anderson, Richard C. Rice, Richard L. Jentgen

"Data for underground mine-hoist ropes determined in the Ontario Special Rope Tests were obtained, encoded and analyzed statistically. Prior 10 refined statistical analyses, these data were subjected la characterization studies and preliminary analyses to allow trends to emerge that could be used to guide and facilitate the refined analysis. The data were characterized by determining distribution s for a wide range of variables including remaining strength, service life in terms of lime and hoisting cycles, outer-wire torsion values, elongation during tensile testing, diameter reduction, location of strength loss and the strength lasses associated with corrosion rating and lubrication rating , This paper describes the more important relationships between remaining strength (or, conversely, strength loss) as the dependent variable and some of the principal independent variables mentioned above.IntroductionBoth productivity and safety in underground mines could be improved if mine-heist rope Iife and reliability could be predicted more accurately . As a result, hoist-rope failure processes and their effects on rope life and remaining strength need to be quantified and related in such a way that improved retirement criteria can be developed. This is true whether the failure is incipient or actual or whether the failure mode is by corrosion , wear, fatigue or a combination of these factors."

Jan 1, 1984

By A. J. Makoka, B. C. Qi

Reliable monitoring of corrosion is vitally important in the combat against corrosion and over the last two decades the interpretation of electrochemical noise has received considerable attention as a means to discriminate between different types of corrosion. To this end, many different analytical methods have been proposed, such as power spectral density analysis and analysis via various other stochastic criteria. However, although many corrosion systems are nonlinear and therefore not readily interpretable by the abovementioned analytical approaches, few studies in the analysis of electrochemical noise to date have exploited advances made in the analysis of nonlinear systems. In this paper, the use of phase space methods to analyze and detect change in corrosion systems via electrochemical noise is considered. In particular, the electrochemical noise data are used to reconstruct trajectories in the so-called phase space of the system and changes in the topology of these trajectories or attractors as represented by correlation dimension curves are consequently interpreted as an indication of change in the dynamics of the system.

Jan 1, 2005

By D. C. Peck, H. D. M. Cameron, N. M. Halden, L. S. Jobin-Bevans

Abstract-The late Archean Pipestone Lake anorthosite complex (PLAC) is a 0.9 x 17 km sill-like layered intrusion that is part of a suite of coeval megacrystic anorthosite bodies in the Cross Lake region, northwestern Superior Province. Exploration for Ti-V-Fe oxide mineralization and concurrent geological investigations have contributed to a greater understanding of the lithostratigraphy of the PLAC and its oxide mineralization. Mapping and drill core studies have established a laterally continuous igneous stratigraphy comprising six leucogabbro/anorthosite zones and three melagabbro/gabbro zones. Field evidence, including disrupted blocks of layered units, scour contacts, and size-graded and modally-graded layering, suggests younging towards both the northern and the central parts of the complex. A decrease in the anorthite content of the feldspars from An75 in the south to An30 in the north suggests that the magmas become more evolved to the north. Macrorhythmic layering and gross morphological features suggest that the PLAC crystallized from four major influxes of geochemically similar basaltic magmas. The paucity of magmatic erosional features in the PLAC indicates that layering developed in a relatively static magma chamber, so that in-situ crystallization processes are required to account for the observed petrologic diversity. Drilling has confirmed that a significant Ti- V-Fe resource is contained in two of the four discrete mineralized subzones in the PLAC. Textural evidence and the stratiform nature of the oxide-enriched subzones are consistent with a magmatic origin for the oxide mineralization.

Jan 1, 1997

By A. F. Gregory

"AbstractA resumé of aerial radiation survey studies performed by and for Eldorado Mining and Refining, Limited, since 1943 is presented. Flight tests were initiated in 1947 and were followed .by intensified use and study of Geiger counters and other radiation detectors. Development of an aerial scintillation counter began in 1948, but •a sensitive large crystal unit was not available for exploration purposes until 1950. Modifications of this unit have been used in all subsequent surveys.For the Eldorado detector, several limiting conditions were established for successful radioactivity detection, the most important being that natural vein exposures can only be assuredly detected .at distances less than 150 feet. Sedimentary and pegmatitic radioactive occurrences can be detected at much greater distances. A helicopter investigation technique appears to •have •a useful prospecting potential.IntroductionAerial radiation surveys were first proposed in the early 1940's. However, it was not until 1949 that airborne detectors were extensively used in the search for radioactive minerals. Eldorado has flown about 50,000 miles of exploration flights, exclusive of tests, using a variety of •detectors and aircraft. Considerable data have •been gathered for .the evaluation of the several techniques employed. Much of the early work was performed with the co-operation of the National Research Council of Canada ( 1). More recent work was done in conjunction with the Commercial Products Division of Atomic Energy of Canada, Limited. The Development Department of this latter corporation designed and built the scintillation counter used in recent Eldorado surveys."

Jan 1, 1955

By Louis Cabot

A pilot plant of the Modular Gold Processing Unit (MGPU) was designed, installed and operated, over a 8 months period, by RSW-Béroma, at the Granada Mine located near Rouyn-Noranda, Quebec. A description of the project geology, plant set up as well as exploitation results, including productivity and profitability curves, are given for a small scale mining operation in comparison with larger ones. Copyright ã 2001 CIM

May 1, 2001

By Peter Radziszewski

"Comminition process costs, which typically represent an important contribution to mining operating costs, can themselves be divided roughly between energy and liner /charge wear. As such, developing the ability of predicting mill wear will allow a more accurate estimation of wear costs and therefore their control. In this paper and based on the possibility of estimating energy dissipated in impact and abrasion by using a discrete element charge motion model for mill charge motion simulation, media wear will be investigated principally as a function of three wear mechanisms : impact, abrasion and corrosion. Experimental results will be used to identify a total media wear model. Model results will be compared with real mill data from three operating Australian mines. These preliminary results show for the cases tested that the overall average error, as compared with the observed cases, is 0 % with a standard deviation of 66.1 %. Results from the Bond abrasion index tests, for the same cases investigated, give an overall error of 73 % and a standard deviation of 192.5 %. Further work is in progress to improve test procedure, validity and confidence.INTRODUCTIONComminition process costs, which typically represent an important contribution to mining operating costs, can themselves be divided roughly between energy and line / charge wear. In Greenfield situations where the estimation of operating costs is critical in determining project feasibility, the level of confidence in such estimates becomes quite important. With regards to media wear, the Bond abrasion test currently serves as the standard media wear prediction device. However, as shown [l, 21 test results once compared with actual wear rates can vary greatly. Figure 1 shows test results as compared with 15 cases. Average error over this data is 73 % with a standard deviation of 192.5 %. As such, developing the ability of more accurately predicting mill wear will allow greater confidence in wear cost estimation and therefore their control."

Jan 1, 2001

By D. A. Garland, A. D. Jackson

"Alanx ceramic/metal composites are proprietary products developed by Lanxide Corporation who joined with Alcan to form Alanx Products L.P. in 1988. Alanx ceramic/metal composites are composed of silicon carbide in a combined alumina and metallic aluminum matrix. In laboratory slurry wear tests conducted by Alanx ceramic/metal composites have shown to perform well against other wear resistant materials. At the Kidd Creek Concentrator Alanx CG896 ceramic/metal composite was tested in two pumping applications, the primary cyclone feed pumps and the filter feed pumps. In both instances the wear rates of the parts made of Alanx CG896 were far less than the gum rubber parts traditionally used. As of year to date September 1992 the unit cost to repair primary cyclone pump parts has dropped 58% from 1991 figures. For the filter feed pumps the unit cost to maintain the pumps has dropped by 33% as compared to 1990 figures. The total savings represented by implementation of Alanx wear parts, based on projected year end unit costs for 1992, as compared to 1991 costs for primary cyclone feed pumps and 1990 figures for filter feed pumps, is $166,753. INTRODUCTIONAt the Kidd Creek Concentrator the cost to maintain the primary cyclone feed pumps and the filter feed pumps was a constant concern. Rubber wear part consumption was quite high and the manpower required was considerable. For 1991 the total cost to maintain five primary cyclone pumps was $244,062. The cost to maintain the filter feed pumps in 1990 was $72,076. A wear material was needed that would increase the time between repairs and that would increase the reliability of these pumps between scheduled shut downs."

Jan 1, 1993

By F. Tanaka

Copper losses to discard slag have long impacted on the profitability of copper smelters. Businesses based on the treatment of secondary materials have also revealed that copper losses are indices of precious-metals losses. Many custom smelters are thus required to obtain more reliable controls for reducing copper losses than ever before. Mitsubishi Materials Corp. has cooperated with academic research institutes in conducting research projects on the pyrometallurgical fundamentals of copper smelting systems, including mutual evaluation of magnetite behavior between synthetic and industrial slags. The state-of-the-art pyrometallurgy has subsequently been introduced to Naoshima smelter for controlling the Mitsubishi process. The revised controls function successfully and the operational results demonstrate that avoiding the discharge of solid magnetite from the S-furnace is quite effective to reduce copper losses. Magnetite behavior has been controlled over the Mitsubishi process so as to reduce copper losses while satisfying the needs of recycling businesses growing in Japan. In-situ estimation of magnetite behavior using the absorbed heat from the melts to cooling water will also be discussed.

Jan 1, 2007

By P. Fossi

This report describes a pilot-scale study of a hydrometallurgical process to treat high-grade nickel matte or a nickel-cobalt sulphide precipitate to produce high-purity electrolytic nickel. The first step of the process is the oxidative leaching of the nickel-bearing material by nitric acid; the nitrous gases generated during leaching are reconverted to nitric acid. The crude nickel sulphate nitrate solution is purified and is then subjected to a denitrification step. Nitrate separation is effected either by the crystallization of nickel sulphate or by precipitation of basic nickel carbonate. The electrolyte is prepared from the nitrate-free material and nickel is then recovered by electrolysis of the sulphate solution using insoluble anodes. Some technical and economic problems encountered with this processing route are discussed and the method is compared to the "all-chloride" process developed by Société Le Nickel.

Jan 1, 1977

By Peter M. Watt

The objective s of this paper are: (a ) to examine and discuss the burdens we place on our extractive industry; (b) to compare the levels of taxation in Canada with those in other countries; and ( c) to suggest certain broad parameters within which our taxation policies may be made more rational and stable. Among the burdens identified are taxation, the ownership and use of our resources, environmental issues and the rather emotional issue of so-called 'super profits'. Finally, the paper will address certain broad but key areas of policy which need attention and agreement if our tax system is to be made more rational. Such areas include: whether and if so why the extractive industry should be given incentives;. what circumstances, if any, justify a 'higher' than normal' level of taxation, and, ?if the concept of economic rents is a justifiable one, how might a basis for them be established which recognizes the fluctuating value of much of the industry's output. Note: The paper was written before the 1977 Federal and Provincial budgets were presented. Consequently, the paper does not reflect any changes proposed in these budgets.

Jan 1, 1977

By Robert J. Mitchell

A general approach to mine backfill design, including laboratory testing procedures, is outlined in this paper. Relationships between certain design parameters are developed and the effect of other factors is discussed. It is concluded that the inclusion of backfill design calculations at an early stage of mine design can often produce over-all design economies. Not only are the data needed for backfill plant and tailings disposal area design, but also the pillar recovery method and over-all mine stability are dependent on the attainable fill properties.

Jan 1, 1979

By Marc C. Bétournay

Replacing diesel power in underground metal mining vehicles with available clean energy (e.g. hydrogen, lithium-ion batteries) is now a priority due to worker health issues, the increasing price of diesel, ventilation costs and air quality. Hydrogen fuel cells are a known and broadly applied power technology. They have been the focus of a dedicated research program to carry our proof of concept projects as well as regulatory developments for mining application. However, hydrogen remains a demanding energy vector to use in confined, underground applications. Standardization and safety considerations are being addressed in the industrial consortium Hydrogen Mine Introduction Initiative (HMII). Research projects are being carried out to resolve the gaps for regulated use. This article focuses on HMII objectives and Project results. The first has reviewed the relevant codes and standards and mine regulations, indicating that hydrogen and fuel cells could be allowed underground and that current codes, especially the Canadian Hydrogen Installation Code would be sufficient for hydrogen use. The second project established the standard hydrogen storage and distribution architecture along with related risks and safety requirements for its use in the third project, using an underground test chamber to delineate the behaviour of hydrogen leaks in confined conditions with various ventilation regimes and ignition studies. This project will end in 2013. It will be followed by the last project, which will establish best practices in support of regulations development, and develop the ISO standard for mine hydrogen infrastructure and underground application.

Aug 1, 2013

By K. Meshinchi Asl

In this study the effects of T4 and T6 heat treatments on microstructural characteristics of AZ91 alloy containing Rare Earth elements have been investigated. Formation of intermetallic Al1 1RE3 needle shape particles which have a good thermal stability reduces both formation of ß(Mg17A112) and discontinues precipitation in AZ91 alloy which are dominated at the grain boundaries and are responsible for poor mechanical properties specially in elevated temperatures. For AZ91-RE samples both T4 and T6 heat treatments led to a continuous precipitation of ß particles at the grain boundaries after aging. However, in AZ91 samples (with no Rare Earths) precipitation was discontinuous at grain boundary areas. This type of precipitation is one of the main reasons of poor mechanical properties of this alloy at elevated temperatures.

Jan 1, 2007

By Joseph F. Daniels

In recent considerations of the utilization and beneficiation of coal, the chemise and the chemical engineer have been occupying the centre of the stage with their presentation of the picture of new fuel forms. The stage hands and supernumeraries of the cast, the miners and the consumers who carry the brunt of the present-day burdens, are apt to be forgotten in the glorious settings and the climaxes. With no thought of disparaging or of minimizing the efforts of our fellow scientists, let us remember that economic considerations as well as technical difficulties will limit these chemical applications, which must develop and move slowly before reaching the stage of industrial application at some later day. In the meantime, the coal-mining industry must live on hard faces rather than rosy dreams. In these brief notes it is my purpose to call attention to some of the physical advances in the utilization and beneficiation of coal which have been of interest to the industry in the State of Washington.

Jan 1, 1928

By Anthony T. Eyton

Intelligent Systems: Advantages for Mining ? Increased safety (reduced risk to workers) ? Increased productivity (reduced downtime) ? Reduced maintenance costs ? Customized solutions for different mines ? Growing acceptance among mine managers A Typical Precarn Project ? Meets definition of intelligent systems ? Involves at least two Precarn members ? a technology developer partner and a user partner ? in a true collaboration ? Involves at least one university and may have various other players ? Leads to a demonstrated prototype ? Costs $2-4 million, and lasts 12-30 months ? Gets up to 40% of its funding from Precarn (max. $1 m) ? Produces new intellectual property -- owned by the project team

May 1, 2002

By A. -M. Lafront

The corrosion resistance of die-cast and freely-solidified and electromagnetically-stirred thixocast AZ91D alloy has been studied using electrochemical noise technique in a 0.05M NaCI solution at pH 6.1 and 25°C. Specimens polished at different depths were immersed for a period of 75 min in order to assess the influence of the microstructure on corrosion kinetics and morphology. At depths between 10 and 50 µm (skin), all specimens showed general non-uniform corrosion with the lowest corrosion resistance. Between 100 and 200 µmn (interior skin), the observed corrosion was accompanied by superficial undefined pits due to metastable pitting. The corrosion form for 100-200 µm gave the best corrosion resistance. Stable pitting corrosion was observed beyond 400 µm deep on the bulk specimens. The skin of all thixocast specimens prepared billets showed a more corroded surface than that of die-cast. The interior skin as well as the bulk specimens showed better performance than that of the die-cast specimens.

Jan 1, 2007

By D. H. Schwarz

The performance of proton exchange membrane (PEM) fuel cells depends on catalyst layer composition and structure. Experimental observations reveal that state-of-the-art catalyst layers consist of microporous agglomerates of carbon-supported catalyst sites bound together by polymer electrolyte. In between the agglomerates are macropores which provide pathways for the transport of gaseous reactants. In this work, three-dimensional, multicomponent and multiphase transport computations are performed using a computational fluid dynamics (CFD) code (FLUENTTM) with a new PEM fuel cell module, which has been further improved by taking into account the detailed composition and structure of the catalyst layers using a multiple thin-film agglomerate model. In this model, it is assumed that thin films of polymer electrolyte and liquid water surround the catalyst sites. The results of CFD computations show that transport limitations associated with the thin film of polymer electrolyte and the presence of liquid water in the catalyst and gas diffusion layers have substantial negative effects on PEM fuel cell performance. Also, the results of computations with variable distributions for a given precious metal loading show that, in general, uniform catalyst loading provides the best fuel cell performance.

Jan 1, 2005