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By P. Woo, N. Brodusch, R. Gauvin, H. Demers

For developing new technologies, it is important to characterize the microstructure of materials with high spatial resolution at the nanoscale. To achieve high resolution, field emission scanning electron microscopes (FE-SEM) were developed. These microscopes allow working at low accelerating voltage, below 5 kV, to take advantage of the reduction of the interaction volume with accelerating voltage. Furthermore, their higher gun brightness compared to conventional thermo-electronic emitters, allow a probe size at the nanoscale. At low accelerating voltage, the emission volume of backscatter and secondary electron (SE) of the type II signals approach that of SEI signals. However, it is not enough to reach the highest resolution. A magnetic field above the sample improves the spatial resolution by collecting mostly high-resolution signals. In addition, the energy-filtration of the electron signals allows selecting the type of contrast detected: topographic, compositional, or crystallographic. The development of these new technologies permits to extend the imaging capabilities of the SEM towards new nanoscale applications.

Jan 1, 2014

By Y. Kocaefe, D. Bhattacharyay, D. Kocaefe

The carbon anodes used in the electrolytic production of aluminum are made of petroleum coke, recycled anodes and butts, and coal tar pitch. Due to technological advances in the aluminum production technology, aimed at increasing production and decreasing energy consumption and greenhouse gas emissions, better quality anodes are required. Presently, the anode quality is evaluated by visual inspection and the analysis of a small core taken from 1.5-2% of the anodes produced. The visual inspection is susceptible to human error and limited to surface imperfections. The analysis of cores takes time, and therefore, it is difficult to determine the existence of a problem and intervene at the right time. In addition, the core does not represent the whole anode due to the non-homogeneity of anodes. A validated online anode quality control system can highly improve the situation. In this article, an electrical resistivity measurement method developed for this purpose is presented.

Jan 1, 2014

By P. Pal Roy, R. B. Singh

"This paper focuses on a number of interesting results to establish the theory and principle of air-deck blasting. It also gives the mechanism of breakage that takes place in air-deck blasting under varying charge load conditions. With these aspects in mind, the mine management can implement this up-coming technology to enhance safety and higher productivity. IntroductionThe method of air-decking has become an increasingly popular technique in production and presplit blasting. In the blasthole, an explosive column is combined with an airchamber. The main aim of the technique is to control breakage through effective distribution of explosive energy and thereby enhance uniform rock fragmentation. An air column lowers the initial pressure of the explosive products and simultaneously increases the time of interaction for the detonation front with the surrounding rock, which enhances rock breakage.To study air-deck blasting, CMRI initially conducted experiments using indigenously developed, low-cost wooden spacers of different sizes and strengths. Air-deck blasting was first tried using these spacers in 1993 at Jambad OCP, ECL and Chasnalla OCP, IISCO. The experiments were extended in 1994 at Bermo Mine, DVC. The results were subsequently published by Pal Roy et al., in 1995. It is worth mentioning that the performance of air-deck blasting during this period was only compared with conventional blasting practices without going into detail of the theory behind the process."

Jan 1, 2001

By Bradley Stoughton

It is very easy to reduce iron ore at a temperature well below its melting point and produce a more-or-less-pure metal which can be used directly for implements, tools, or machines. This simplicity has been the cause of much money loss by persons who were so satisfied with the successful operation of a process that they paid all too little attention to the commercial aspects of it. How easy a direct process is may be gleaned from the fact that it was practised with some -success by primitive man, and has been in almost continuous operation in one form or another for a period of probably 4,000 years. The production of steel in ton lots, beginning about 1860, brought a new phase into the economic situation, which, however, had been already greatly modified in 1784 by Henry Cort's invention of purifying pig iron. Direct processes survived both of these revolutions, under special geographical conditions, even up to the last few years of the nineteenth century, but ceased to have any general use as the basis of supply for structural, machine, or tool industries even in countries which could have manufactured iron by a direct process, but, instead, imported the product of established iron and steel processes. And this is still the situation today, notwithstanding the invention of an incredible number of 'new' processes since 1900, most of which are abandoned, and only survived as along as their financial backers were willing and able to Jose money. Probably none of these processes failed to work pretty well, and all seemed to show a handsome profit on paper.

Jan 1, 1930

By D. Janney

Kennecott's Utah Smelter commenced operations in June 1995 utilizing Outokumpu Flash Smelting (FSF) and Kennecott-Outokumpu Flash Converting (FCF) technology. After some initial teething and equipment problems the smelter achieved its design capacity in mid-1997 and now processes over 1.0 million tonnes of copper concentrate per year with exceptional environmental performance. The smelting furnace has operated for 11 years and the converting furnace for 5 years without major shutdowns. The first major smelter shutdown commenced in September 2006 after extensive planning. The FSF was completely re-bricked and the latest above and below bath containment systems installed. The FCF was inspected and re-bricked with some improvements made to the above bath containment system. The FCF life is now anticipated to be the same as the FSF. Numerous improvements and modifications were made to the rest of smelter facility including extensive upgrades to the dry electrostatic precipitators. Production ramp-up was smooth with the smelter now frequently operating at acid plant capacity.

Jan 1, 2007

By Andrew J. Freyman, Graham T. Armstrong

"In September, 1968, a survey of operating mines in the Yukon and the Northwest Territories was undertaken to determine the role of Indigenes (Indian, Metis, Eskimo) on the mines, and the attitude of mine management to these employees. The operating mines in the Territories had (at that date) a total employment of 2,002 men, of which 91 (4.5 per cent) were Indigenes. Indigenes make up 45 per cent of the Territorial population (18 per cent in the Yukon and 63 percent in the Northwest Territories). The paper documents some of the problems associated with indigenous employment in mines. A study was undertaken to determine the role of Indigenes (Indians, Metis, Eskimos) in operating mines in the Yukon and in the North-west Territories. In addition to the mines north of the 60th parallel, the experience of several other Canadian mines was examined. The general picture obtained is considered to be representative of the Canadian mining industry."

Jan 1, 1969

By Narasimha Mangadoddy, Teja Reddy Vakamalla

"Vertical hydrocyclones are very common in most of the comminution circuits. Inclined cyclones are also found for specific mineral processing applications. In this work, Computational Fluid Dynamics (CFD) technique and experiments are used to find the reasons behind the inclinations effect on hydrocyclone performance characteristics. The water and silica slurry experiments are conducted with 75 mm hydrocyclone at different inclined positions (0-600) to the vertical plane. Corresponding two-phase numerical simulations are performed with Volume of Fluid (VOF) model coupled with Large Eddy Simulation (LES) turbulence model. Multiphase simulations are carried out with Algebraic Slip Mixture model modified with lift, drag forces and Newtonian rheology model corrected with fines for various feed solids concentration. A raise in the under flow solids percentage, cut diameter and a reduction in the water split is observed with the inclination. Electrical Resistance Tomography (ERT) and High Speed Video (HSV) data is used to cross validate the inclined cyclone’s CFD air-core and solids concentration data. Predicted efficiency curves are found in a close agreement with experiments for all the inclinations. Comparison of experimental and predicted flow data clearly follows trend with the literature. Key words: Hydrocyclone, CFD, ERT, inclination, water splitINTRODUCTIONHydrocyclones are devices used to separate or classify particles based on particle size difference in the water medium. Their usage is very wide in chemical, petroleum, mineral and bio industries due to its structural simplicity, high throughput, small volume, low cost and maintenance. Cyclone mainly consists of a cylindrical section followed by a conical section attached to a single feed inlet and two product outlets named vortex finder and spigot. It works on the principle of centrifugal sedimentation. The slurry is fed tangentially to the hydrocyclone, in which larger particles are moved towards the wall and separated by centrifugal forces to the underflow. Smaller size particles follow liquid due to drag forces to the overflow. With its simple structure, the flow behavior inside the hydrocyclone is quite complex. Vertical cyclones are common in practice in most of the comminution circuits. Horizontal cyclones can be found in extreme cases which are for installation convenience rather than for process reasons. Inclined cyclones are also present for specific mineral processing applications. In coal preparation plants, dense medium cyclones are operated near to horizontal inclination of 20 degrees to allow large spigot sizes for sinks removal, self-drain of contents during shutdown. In the phosphate removal, dense medium cyclones are inclined with an angle between 0-90 degrees for better separation of ore and tailings (Liu Feng et al., 2006). Even in the clusters, hydrocyclones are mounted with an inclination around the feed distributor for uniform distribution of slurry and under flow collection. It is believed in mineral processing industry that inclined cyclones would fetch the benefit in number of ways while classifying the material by size. Gravity influences the cyclone performance through the air core size and position variations in large cyclones. It also favours the cyclone operation at coarser cut points without varying any other design and operating parameters. Minimizing fines misplacement to underflow can be achieved with inclination."

Jan 1, 2016

By M. A. Bergougnou, I. Inculet, K. I. Burgess

This paper describes the electrostatic methods of separating various minerals, reviews the principles of fluidization and outlines the technique of electrostatic sorting in fluidized beds. The application of the method to the benefication of coal is emphasized.

Jan 1, 1970

By M. Kucharski

The model of the Outokumpu direct-to-copper process deals with a steady-state process the parameters of which do not depend on time. To give a prediction for the process outcome, "a modified black box" method, which ignores most of the chemical reactions in the furnace, was used. This method takes input and output parameters into consideration. The presented model describes the Outokumpu direct-to blister process in the form of the set of linear equations which give mass and enthalpy balances as well as the distribution of elements between blister copper and slag. However, only major substances where quantities in the feed charge exceed a certain level (for example 0.5 kg/ lMg of smelted concentrate) are taken into consideration. Minor elements are distributed among slag and metal phases in a different way. Some of the equations are derived from distribution coefficients. The value of distribution coefficients can be calculated from plant production data.

Jan 1, 2007

By A. A. Rafiei, J. A. Finch

A previous study comparing n-pentanol and the polyglycol Fl50 showed that the two reagents could give the same gas holdup but with different size bubbles. The finding implies that bubble rise velocity depends on the surfactant (frother) type. A study using bubble swarms supported the frother type effect but bubble interactions were a possible confounding factor. This study resolves the question by measuring the rise velocity of single bubbles of 0.8-2.5mm diameter over a distance :::: 300cm in n-pentanol and F 150. It is shown that at typical frother concentrations used in flotation that the rise velocity in n-pentanol remains comparable to that in water alone while in Fl50 the velocity is significantly reduced. The results confirm the suspected impact of frother type. It is illustrated that in n-pentanol the rise velocity does not reached terminal; while in Fl50 it does and this is the source of the velocity difference. Advances

Jan 1, 2009

By J. C. Gilbert

"IntroductionTHE PURPOSE of this paper is to discuss in a general way the heavy oil situation in Western Canada, and particularly to acquaint those in the oil industry who have not participated in the heavy oil end of the business with past and current developments. The author has covered •briefly the location of the heavy •and asphalt-base oil fields, their geology, current drilling and production practice, the location of the •refineries capable of handling heavy crude, their products and markets, and the problems and future prospects of the industry.Location and Description of FieldsThe term heavy oil is generally used to denote crude of 20.9° gravity and under. Since the products from heavy oil are also to a lesser extent obtained from asphalt-base crudes of higher gravity, some mention will be made here of the latter; but in general the emphasis of the paper is on heavy oil as such.In the order of their production to date, the heavy oil fields and those light oil fields which produce asphalt-base crudes are : Lloydminster, Taber, Vermilion, Conrad, Princess, and Wainwright.The Lloydminster oil field has not only produced most of the heavy oil, but also is currently the largest producer, supplying at the present time about 80 per cent of the heavy and asphalt-base crudes produced in Western Canada."

Jan 1, 1952

By H. D. B. Wilson

THIS PAPER has resulted from a preliminary draft of a background paper prepared anonymously for the Science Council's Special Study of the Solid-Earth Sciences in Canada. The draft was circulated to eighty-four Canadian geologists; forty-eight of these responded with criticisms of the draft. All critical re-marks were considered carefully and most have been incorporated in the final paper in an attempt to balance the author's bias, although this bias undoubtedly still appears. Indications of support for a particular statement or section were also helpful, because many of these contradicted criticisms and enabled the author to judge the consensus. Thus, all criticism could not be incorporated because the referees did not agree. It is interesting that some remarks were con-sidered overstatements by some and too bland by others. The most perplexing critical comment was one which suggested a new author was needed, and went on to name the existing author as the most likely candidate.

Jan 1, 1970

By Arthur M. Whiteside

Discussion of the laws bearing upon the economics of mining in this province at once resolves itself under three headings: (a) The rights and obligations of holders of mineral bearing lands; (b) Taxation of mines; (c) Regulation of methods adopted in financing mining operations. Titles: The law relating to titles is contained in the Mineral Act, Placer Mining Act and Coal Mines Prospecting Act. Origin: Mining laws in force in this province and elsewhere on the continent had their origin in the rule-of-thumb regulations adopted by prospectors themselves, when, far from the centres of civilization and the seats of the courts of justice, they found it necessary, for mutual protection, to fix the conditions of possession by right of location, and to prescribe the duties to be performed in order to enable the individual to maintain his ground against all comers. These regulations have been codified and added to by legislatures, until we find adequate protection and safeguard to property in the laws of this province.

Jan 1, 1924

By K. Spence

"The notion of “value” has always been a subjective and contentious issue. Indeed, value is in the eye of the beholder. There are as varied methods and practices for valuing property, as there are industries in which they are applied. For example, there is replacement value, insurance value, salvage value, appraised value, book value, and fair market value, to name a few, although in the mining industry, valuations usually refer to fair market value.In the Canadian mining industry, at present, there are no comprehensive regulations or guidelines that specify which approaches or methods are appropriate for use in the valuation of mineral projects. In January 1999, The Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission recommended that the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) establish a committee to review and advise on approaches and methodologies for the valuation of mineral properties. Among the approaches to be considered are included the following: the discounted cash flow approach, the cost approach, the option pricing approach and the market comparables approach. In addition, methodologies differ depending on whether the project is at the exploration stage or the producing stage.The CIM Special Committee on the Valuation of Mineral Properties (CIMVal) expects that its final report will form the basis for a Canadian code or standard for the valuation of mineral properties."

Jan 1, 2002

By T. G. Edgeworth

Some of the historical background of the industry is reviewed, with reference to the different types of reduction cells in use for aluminum smelting. Factors to be considered in cell des1gn involve capital, power, and operating costs. The trend is apparently toward larger cells. The industry is studying new construction materials for cell linings, as well as alternate electrolyte compositions and other design changes which will improve productivity and energy efficiency. The aluminum smelting activity in other countries is briefly reviewed. TODA Y'S industrial production of aluminum is still based on the simultaneous discoveries made in 1886 by Charles Martin Hall in Ohio, and Paul Heroult in France. Up to that date, only about 50 tons of aluminum had been produced in the world, and the price at that time was about $5 per pound. Sucl1 figures must be contrasted with the present world aluminum smelting capacity of over five mil-lion tons per year, and a price of about 25 cents per pound.

Jan 1, 1962

By M. F. Goudge

This paper is intended to call attention to the manifold uses of limestone in industry; to indicate the types of limestone desired by some of the large consuming industries; and to give some information on the resources of limestone in Canada, so that an idea may be obtained of the present and future possibilities for limestone production. The word limestone is used in the usual broad sense to include both high-calcium limestone and the highly magnesian variety known as dolomite, as well as all intermediate types. Lime is simply calcined limestone, and in this general paper its uses have been included with those of raw limestone. It is of interest, in dealing with this subject, to glance back over the early history of the utilization of limestone, for by so doing we see that limestone has been of importance to mankind since the beginning of civilization and has contributed in no small measure to the development of a number of the arts and sciences. One of the first uses, if not the first use, of limestone was in connection with the making of lime for plastering purposes. This use antedates civilization. In the day of the ancient Greeks and Romans, the art of plastering had been brought to a state of perfection that is not nearly approached by the modern artisan.

Jan 1, 1930

By Jin Li

The tensile properties and microstructure of AZ91 Mg alloy before and after equal channel angular extrusion (ECAE), and the fracture behavior during tensile testing for as-extrusion and ECAE AZ91 were investigated. The alloy was performed ECAE from one to eight passes at 498K. The elongation decreased with the pass number increasing after ECAE. Grains were refined, partial coarse ß-Mg17Al12 phase fell to pieces, fine ß-Mg17Al12 precipitated in the AZ91 Mg alloy after ECAE. During tensile test the a-Mg/ ß-Mg17Al12, a-Mg/Al8Mn5 interface and the grain boundaries in a-Mg matrix acted as the crack initiation sources. The frequency of micro-cracks at the a-Mg/ß-Mg17Al12 interfaces and grain boundaries increased after ECAE, which accelerated the growth and coalescence of the micro-cracks during tensile test and resulted in the decrease of elongation of AZ91 Mg alloy by ECAE.

Jan 1, 2006

By Hulbert A. Lee

"A REVIEW OF MINERAL DISCOVERIES IN CANADA, and in particular the Canadian Shield, using the physical aspects of overburden reveals a trend in the art of exploration. At an early time of exploration (1847-1954), float and heavy clasts were used successfully to find ore deposits with little knowledge of Quaternary environments. At a later time (1955 to present) , use of Quaternary rock-units for sampling have made possible tracing indicator trains of float, heavy clasts and other ore-type clasts to the source bedrock. The basal till of retreat ice is now recognized as a1l favourable sampling environment and as such has been used to successfully discover hidden orebodies. The esker massive gravel is beginning to be recognized as a favourable environment and use of it has met with technical success. An understanding of those changes that have taken place during the transportation of the material and after its deposition is essential to proper sampling and treatment of the samples from the basal till and the esker massive gravel. Use of float and heavy clasts in search of orebodies is continuing in present-day exploration on the Shield. Lessons learned from it are being incorporated into exploration using favourable Quaternary rock-units for sampling. Hence, both subjects have a need for review and are discussed in this paper."

Jan 1, 1971

By T. C. Holmes

Introduction The Dome mine, in the Porcupine mining camp of northern Ontario, is one of the important gold mines of the country, having produced over 139 million dollars worth of gold from the commencement of production in '1910 to the end of 1944. The geology of the mine is complex and a number of types of ore are known, each occurring under particular conditions. The mine workings are very extensive and by far the greater part of them have been geologically mapped only in reconnaissance fashion. By 1940, when the writer joined the mine staff, the orebodies in the sedimentary trough and the 'nose' orebodies, the first types to be developed, were almost worked out and many workings were inaccessible, so the descriptions of these types are based largely on study of the plans and records. The same applies to a lesser extent to some other types. At various places in this paper, statements are made as to the mineralogical or chemical composition of the rocks. Most of these determinations are based on examinations made with a hand lens and cannot, therefore, be regarded as very reliable. General Geology As there are several types of ore in the mine, occurring under quite diverse conditions, a brief outline of the geology is given here, sufficient to provide a general picture into which the fuller descriptions given with each type of ore can be fitted.

Jan 1, 1947

By C. M. Campbell

THE dire effects of rapidly vanishing natural resources, widespread unemployment, and increased debt and taxation in recent years have challenged Canadians to produce a practical solution to these national economic problems. In more recent months, wars and rumours of war have indicated, among other things, the need for better control of our mineral wealth. The erection of a smelter on the lower mainland coast of British Columbia, treating all Western ores, and such ores as it will be found advisable to import, will make an important contribution toward a solution of these problems. It is believed that the ores tributary justify a smelter of major proportions. A stock-taking to confirm this can be made with reason-able accuracy in a short time, and this should be undertaken without delay. Enough general information is, however, available .in this paper to justify the technicians of the Department of Mines at Ottawa and of interested smelting companies making a preliminary study of the matter. THE DEFENCE ARGUMENT As a factor in rearmament, metals play a vital part. That rearmament is to continue on an increasing scale is indicated in Premier Chamberlain's address of October 3rd last, when he said: ?'For a long period now we have been engaged in this country in a great programme of rearmament which is daily increasing in pace and volume. let no one think because we have signed 'this agreement between the four powers at Munich we can afford to relax our efforts or call a halt in our armaments at this moment'. As matters stand, the facilities in British Columbia are entirely out of line with the strategic importance of this Province as the Western Front of Canada and the Empire. All our copper ores, and an appreciable part of our lead and zinc ores, are sent for treatment to Japan, United States, and Europe, while we import our iron and alloys. A treatment plant on this Coast would not only give us control of war metals and chemicals but it would provide an increased industrial and research population, badly needed in this area and of the greatest value in the case of war. This is where the mining industry can do its bit.

Jan 1, 1939