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By G. S. Headley

At the Sullivan Mine, recent experience with sulphide fires, locally referred to as " hot muck", has necessitated extensive modifications to pillar mining design and operating procedures. Potentially hot pillars are now being designed and mined to prevent fires. Unusual safety hazards and difficulties are encountered in working with, and adjacent. to, existing pillar fires. Operating procedures developed for these conditions have proved successful for safe and continuing production. These changes have minimized the impact of hot ore on current operations and have promise for an improved future.

Jan 1, 1977

By Y. Huang

Corrosion of GaAs in aqueous electrolytes is a major limitation in implementing GaAs-based photoelectrochemical solar energy conversion systems, In this work, the corrosion behavior was investigated by electrochemical methods and surface analysis approaches, in both H2SO4 and NH3?H2O solutions, Open-circuit measurements showed that the cleaned GaAs surface was very sensitive to water/air, Impedance measurements for n-GaAs showed that an inductive loop only appeared at a high corrosion rate because a reaction intermediate is the oxidant for a further decomposition step in combination with chemical reaction with water, The results suggest that the same corrosion/decomposition mechanism occurred on n-GaAs in the two solutions, When the surface-hole concentration was low, the hole injection or generation process was the rate-determining step, At large reverse bias on n-GaAs, with high-hole concentration, the corrosion rate was limited by a Faradaic adsorption process, involving an adsorbed intermediate, The different surface compositions after corrosion in the two solutions can be explained by the dissolution of As(0), Further oxidation of As(0) to As(III) in NH3?H2O solution is still slow, as suggested from X-ray photoelectron spectroscopy (XPS) analysis,

Jan 1, 2005

The negative effects of pyrite and pyrrhotite on thiosulfate gold leaching have been investigated. Possible remedies to reduce some problems are discussed. In a gold bearing pure silicate ore, 92% of gold could be extracted within 3 hours using a solution containing 0.2 mol/L ammonium thiosulfate, 0.9 mol/L ammonia, 30 - 300 ppm copper sulfate and 8.6 ppm dissolved oxygen at pH 10.26. The thiosulfate consumption was 7.1 kg/t under these conditions and could be further reduced to 3.5 kg/t by decreasing the dissolved oxygen to 0.3 ppm. Addition of 16% pyrrhotite or pyrite into the silicate slurry led to a decrease in gold extraction by 2% or 9% respectively and an increase of thiosulfate consumption by 11 kg/t or12.8 kg/t respectively in three hours. Several adjustments, such as increasing copper ion and ammonia concentration and reducing the dissolved oxygen level to 0.3 ppm resulted in increased gold extraction and lower thiosulfate consumption despite the presence of these sulfides.

Jan 1, 2005

By W. G. McBride

THE present demand for men with engineering training exceeds anything in the history of the profession. Recent estimates indicate that mechanization of war has reached such a stage that at least twelve horsepower is required now for every one horsepower needed to run the machines of the first Great War. The scale of operations exceeds anything in the past, while more territory and people are involved than ever before. Many of our allies have inadequate or no facilities for producing the thousand and one articles absolutely necessary to the conduct of modern warfare. Lack of preparedness has made it necessary to produce at an unparalleled rate to gain parity with the enemy, while our losses have been so heavy that replacement, in itself, presents a task which might well stagger less courageous peoples. This means that not only is there an unprecedented demand for engineers to produce the machines, munitions, and supplies of war, but there is a correspondingly large need for men with engineering skill in the uniformed forces to operate and maintain the vast numbers of ships, 'planes, tanks, trucks, radios, and a myriad of other devices to carry on the varied activities of war. This abnormal demand came upon us after almost ten years of stagnation in the engineering industries. During this time many trained engineers drifted into other callings, while the lack of jobs for graduates caused a falling off in the number of men training for this profession. Consequently, the supply of well trained engineers was below normal when the madman of Germany precipitated us into the present turmoil. Added to all this, we in Canada are still suffering from governmental inefficiency in the utilization of the available supply of engineers. In the armed forces, engineers have been assigned to office and other work where their engineering training is not only wasted but for which men with more suitable training could be found. Mining engineers are debarred from service as aeronautical engineers, and students in mining engineering are denied the bursaries provided for aiding students in engineering. Mining and metallurgical engineers are both barred from the Ordnance department of the army. This arises from a misunderstanding in relation to engineering training. In Canadian engineering schools, all engineers are given a sound training in the branches of human knowledge which are fundamental to engineering: mathematics, physics, and chemistry. The basic difference between the several categories of engineers lies in the fact that training in the application of this fundamental knowledge to the solution of engineering problems is given in different subjects.

Jan 1, 1942

By C S. Beals

The Dominion Observatory was founded in 1905 and, from the beginning, it work included research in both astronomical and geophysical science. During its first years, up to 1916, the Observatory also included geodetic surveying as part of it scientific program. Although, at the beginning of the century, geophysics did not have the close connection with mineral exploration that it now holds , the founders of the Observatory were men of vision, and they laid a solid foundation for the application of the techniques of geomagnetism, gravity and seismology to an understanding of the Canadian terrain of plain , mountains, seacoasts and shield area . The particular sphere which the Observatory occupies in the field of geophysics has been evolving over a period of many years and it has now a rather definite relation to the work of other government bodies, university science departments and industrial organizations. We have, for example, an over-all responsibility for the regional magnetic mapping of Canada and, as the magnetic field is subject to slow but steady changes, we produce new magnetic maps of the country every five years. These maps indicate the strength and direction of the magnetic field, the variation of the compass and the rate of change of the magnetic elements.

Jan 1, 1963

By A. Saigal

A finite element analysis based investigation using DEFORM software was undertaken to model the extrusion of 15% alumina and 15% silicon carbide reinforced aluminum metal matrix composites. The study dealt with predicting the extrusion load as a function of ram displacement and initial billet temperature. The finite element simulation was also used to determine the maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions in the billet during the hot extrusion process. The constitutive equation used was of the type: Z = E exp(Q RT) = A{sinh(ao-)}" where Z is the Zener-Hollman parameter (temperature compensated strain rate), s is the strain rate, Q is the activation energy, R is the gas constant, T is the absolute temperature, a is the flow stress and A, a and n are constants. Based on the work of Davies et al and McQueen and Konopleva, the values of Q (KJ/mol), a (MPa-1), n and A for aluminum 6061 composites reinforced with 15% alumina and 15% silicon carbide used are 181, 0.024, 4.15 and 1.33x10'2 and 233, 0.052, 2.60 and 1.26xl0'4, respectively. Even though the individual parameters are quite different, it was found that the predicted maximum extrusion load, temperature distribution, maximum temperature, strain rate, velocity and stress distributions are quite similar and differ by no more than 1-2 percent between the two composites indicating that the deformation behavior is primarily controlled by the matrix material and is not a function of the type of reinforcing ceramic particulates.

Jan 1, 2004

By H. F. Zurbrigg

"The Frood-Stobie Mine is by far the largest metal producer in the Sudbury area. Its efficient development was made possible by the consolidation of three mining properties that covered parts of the same ore body. They were known as the Frood Mine, the Frood Extension, and the Stobie Mine.The southwest or Frood portion of the orebody was discovered by Thomas Frood and A. J. Cockburn in 1884. Cockburn's interest was acquired by J. H. Metcalf and W. B. McAllister and patents were issued to Frood, Metcalf, and McAllister in 1884. The property was purchased by the Canadian Copper Company (lnco) in 1886.James Stobie discovered the northeast or Stobie part of the orebody in 1885. In 1886 Stobie and Rinaldo McConnell applied for the location and patent was issued in 1886. They sold the property to the Canadian Copper Company (lnco) the same year.The Frood Extension property included very little of the ore zone at surface but it covered ore down the dip from Frood. Frank Cochrane was granted title to the property in 1908 and sold it to the Mond Nickel Company in 1910. The title was transferred to the International Nickel Company in 1929 at the time of the Inco-Mond merger.Prior to 1930 the three properties produced a total of about 1 ,000,000 tons of ore from mining done during the periods 1887-1903, 1913-1915 and 1925-1929. Since 1929 the Frood-Stobie operation has produced more than 120,000,000 tons of ore, about half from open pits and half from square set and blast hole stoping. The current production rate is in excess of 6,000,000 tons per year.The principal products from the ore are nickel and copper. The by-products are iron ore, cobalt, platinum, palladium, rhodium, ruthenium, iridium, gold, silver, selenium, tellurium, and sulphuric acid."

Jan 1, 1949

By Fridrik J. Kristjansson, Stephen R. Hicock

"Three varieties of till are recognized in the Beardmore-Geraldton area: local lodgement till, nonlocal carbonate till, and local supraglacial till. The local lodgement till unit is examined in detail for the first time in this paper. It is the best potential overburden exploration medium for gold and other metals because its particles were locally-derived and deposited subglacially, probably within a few kilometres downglacier (southwestward) from their sources, and have not been diluted by distantly-derived glacialdebris. Both local tills are richer in gold and other metals, relative to nonlocal carbonate till. Local lodgement till rests on bedrock and was encountered frequently at or near the surface in thin drift/bedrock terrain (a widespread terrain type within the west half of the study area), and commonly at the base of boreholes in thick till terrain.INTRODUCTIONDrift prospecting in areas of glaciated terrain has been well documented (in a variety of journal publications and symposium volumes; e.g . Strobel and Faure 1987; MacDonald and Mills 1988) and has proven valuable especially where overburden thicknesses hinder traditional exploration techniques. Drift prospecting techniques may well prove valuable in the Beardmore Geraldton area. This applies especially to the Wildgoose Lake Turkey Lake area where a thick and laterally extensive sheet of nonlocal carbonate till has impeded conventional mineral exploration programs (Fig. I; note the lack of gold occurrences around Wildgoose Lake).Till in .particular has been cited as the best prospecting medium among the various types of glacial sediment (e.g. Shilts 1984). Three end member till varieties are recognized in the study area: (I) local lodgement till which rests directly on bedrock; (2) non local carbonate till; and (3) local supraglacial till which occurs predominatly within, or just downglacier of, upland areas where it commonly mantles the other till varieties. Previous authors have documented how the non local carbonate till hinders gold exploration (Geddes and Kristjansson 1986; Karrow and Geddes 1987; Kristjansson 1986; Hicock 1986, 1987a, b, 1988; Kristjansson and Thorieifson 1987; Thorleifson and Kristjansson 1987, 1988a, b) and why the local supraglacial till may be a good unit for prospecting (Hicock 1986). One detailed surficial geology map sheet of the area has been published (Kristjansson et al., 1988) and others are in preparation. Closs and Sado (1981) reported on the geochemistry of soils and glacial sediments in the west half of the study area. This paper documents the local lodgement till unit and demonstrates why it is the best overburden unit to use for drift prospecting."

Jan 1, 1989

By Chris Twigge-Molecey

Demand for metals will continue to grow as global population numbers and prosperity levels steadily increase. Consequently, there will continue to be a need to design and construct new metallurgical plants. Business success in general requires projects to be financially successful and return appropriate value to their owners. However, in the metals industry, private and public sector financing sources have become very sensitive to the perceived inability of projects to contain costs and meet other business objectives. Thus, the capital for projects has become more difficult and expensive to obtain. It is instructive to note that Ernst and Young (2011) identified that: “Delivery of predictable project results bestows competitive advantage and market confidence to those corporations who successfully instill this discipline”. The implication for future projects is that they must be systematically developed to minimize perceived risks—and more importantly—to demonstrate that the risks are managed to achieve the business case. Then, provided that the project has been developed in a well-structured way, project success can again be defined as a project with: a final cost within 10% of the budget approved at the end of FEL3, when the project is properly defined and the permit conditions are agreed upon; a start-up date within three months of the definitive, scheduled startup date; production levels at 85% of design capacity within a year of starting commercial operation; production meeting the target environmental restrictions; and with zero lost time accidents during construction and startup. The plant design is one of many integrated activities required to achieve these objectives. This book represents a valuable link between the existing engineering literature that encompasses a wide range of engineering fundamental textbooks and design manuals and the project management literature such as the Project Management Body of Knowledge, or PMBOK® (Project Management Institute, 2014). It is evident throughout this book, that the design team is a small but essential part of a much larger project team comprising the project management, construction management, and construction contractor staff. Design activities must be regarded and managed as part of the integrated whole, with two fundamental links throughout the design process:

Jan 1, 2015

By Ahmad Ghahremaninezhad, Denver H. Cowan

Much of today’s gold is locked within sulphide minerals. These sulphide minerals, including pyrite, need to be subjected to oxidative pre-treatment in order to leach the refractory-gold using traditional methods. Typically autoclaves employing high temperatures between 180?225 ºC, and extremely high pressures between 1,500?3,200 kPa, are used for the oxidative pre-treatment. However, the autoclaves themselves are very expensive, costly to operate and maintain, and produce excess sulphuric acid. This paper studies the atmospheric oxidation of pyrite in ferric sulphate solutions. In general, pyrite oxidation under atmospheric pressure can result in high elemental sulphur production, i.e. less acid generation. Activated carbon has displayed an ability to catalyze the process, achieving reasonable kinetics. The reaction kinetics were investigated by altering acidity of the leaching solution, temperature, catalyst ratio, sparged oxygen and agitation. A combination of X-ray diffraction, scanning electron microscopy, optical microscopy, X-ray fluorescence, inductively coupled plasma mass spectrometry (ICP-MS), and atomic absorption spectroscopy (AAS) were used to monitor the kinetics of the process and elemental sulphur yield. The purpose of this investigation was to determine optimal operating conditions that maximized kinetics of the atmospheric oxidation while maximizing elemental sulphur yield.

Jan 1, 2015

By S. Joshi, E. Asselin

An electrochemical quartz crystal microbalance (EQCM) was used to study the leaching of pure gold in deaerated 1 M Na2S solution. Multiple cyclic voltammograms were measured between -0.76 and 1.242 V (SHE) at 20 mV/sec and 2 mV/sec and the frequency shift of the quartz crystal was simultaneously measured. Both the forward and reverse scans showed oxidation occurred between -0.40 to 0.20V. The frequency shift increased during both the forward and reverse scans in the potential range of -0.40 to -0.06 V indicating electrode mass decreased. Since at -0.40 to 0.20 V oxidation peaks were also observed, part of the oxidation was due to oxidation of gold. Eh-pH diagrams were constructed and showed soluble Au(I)-S(IV) species formed between -0.30 and 0.10 V (SHE). Atomic absorption spectroscopy of the test solutions and the mass change recorded by EQCM both showed about 0.015 mg of gold leached. Since the majority of the frequency shift increase corresponding to gold oxidation occurred at -0.40 to -0.06 V during multiple cyclic voltammogram measurement, the total leaching of gold could be approximated to occur at this potential interval to give a leaching rate of ca. 6.4x10-5 mg/s-cm2.

Jan 1, 2011

By S. W. Asihene, K. Osseo-Asare

The thermodynamic data necessary for the quantitative treatment of Metal-NH3- H2O systems at elevated temperatures are lacking in the literature. As a result discussions of the chemical basis of high temperature processes, such as leaching and hydrogen reduction, have tended to rely on low temperature thermodynamic data. In this paper a critical review is presented of the available high temperature data for metal ammine formation in aqueous systems, and methods are suggested to enable extrapolation of elevated temperature stability constants from low temperature thermodynamic data. Predictions of the Van't Hoff Lsobar, the simple cation Correspondence Principle (whereby metal ammine complexes are treated as simple cations) and Helgeson's Electrostatic-Nonelectrostatic Model are compared with the available high temperature stability constants for nickel ammines. Up to 80 °C all three estimation methods yield results which are in agreement with experimental data. However, serious deviations occur at higher temperatures; the various models overestimate the stability constants in the order Van't Hoff Isobar > electrostatic-nonelectrostatic model > simple cation Correspondence Principle. Using the experimental nickel data as a basis, a method is presented which permits reasonable estimates to be made of the stability constants of metal ammine complexes for temperatures above 80 °C.

Jan 1, 2004

By Hamid-Reza Manouchehri

Coarse particles flotation is controlled by detachment (particle hydrophobicity and flotation cell turbulence) For composite particles (the bubble may attach to good hydrophobic region, but the expansion of the three phase line of contact is limited. Hence, the equilibrium contact angle, characteristic of the hydrophobic region, may never be attained, and the force of attachment is decreased relative to that possible for homogenous hydrophobic surfaces.

May 1, 2013

By Ramesh Subramanian

Overview Background / History Undergraduate Programs Mining Engineering Chemical Engineering Mechanical Engineering Graduate Programs and Research Student Enrolment (2002 -) Future Plans

Oct 1, 2010

By Jim Robertson

Summary of Presentation ??What is the GARD Guide ??The Need for a GARD Guide ??Mining Industry?s Commitment to Solving ARD Problems ??The Ultimate Solution ?You ??The GARD Guide ?Scope ??The GARD Guide ?Structure ??Wiki Demonstration

May 1, 2009

By K. D. Genn, A. Mucha

This paper deals with Hilton Mines' approach to the maintenance of wear items such as truck boxes, shovel buckets, tractor pads, crawler sprocket idlers and the drop-ball. Each will be given a brief. description as to application, design, kind of materials involved and type of wear. The maintenance procedure is then outlined in terms of materials used, preliminary preparation, and welding and machining practices. The service history of new and re-paired items and the relative economics of repair vs replacement will then be presented.

Jan 1, 1969

By JAMES E. TILSLEY

Veins at St. Lawrence near the tip of the Burin Peninsula in southeast New/ oundland have been the major Canadian source of fluorspar. Some 2.8 million tonnes were shipped during the period 1933-1977, mostly from five of the more than forty veir.s known. Most of the veins occur in granite. individual veins may be several km in length, comprising a number of mineable lenses up to 760 m long and 25 111 thick. Fluorite content averages about 50 per cent, but may exceed 90 per cent locally. Quartz, calcite, barite and a few sulphides are the other vein constituents. Jn recent years, gravity concentrates were shipped to a flotation plant at Arvida, Quebec, where the fluorspar concentrate was used as a flux in the making of alum in um. Competition f rom Mexican fluorspar was a major factor in the closure of the mines. Ample reserves are available should economic conditions improve.

Jan 1, 1984

By D. J. Xue

Four kinds of coal-rock combination were subjected to three kinds of stress waves in the SHPB numerical simulation. The wave propagation and the changes of the strain energy in the coal-rock combination during the dynamic impact process were recorded as well as the contact force. The dynamic response law of coal-rock combination was obtained. It was found that the coal had better reflectivity than the rock because of coal with larger impedance. In contrast the rock had better transmissivity. As the crest value of the incident wave increased, the increment in the crest value of the transmitted wave weakened in the coal-coal group, coal-rock group and rock-coal group, in contrast, the increment in the rock-rock group increased.

Aug 1, 2013

By D. KEYS, D. E. Gemmell

The portion of the earth's surface covered by peatlands has been conservatively estimated at over 420 million ha (Kivinen and Pakarinen 1980). It is estimated that there are about 170 million ha of peatland in Canada. New Brunswick contains about 140,000 ha. Harvesting of peat for horticultural purposes has been carried out in New Brunsiwck since 1942. This industry, and the potential for using peat for energy purposes, indicated the need for an accurate assessment of the resource. In 1975, therefore, the New Brunswick Department of Natural Resources began a detailed peatland inventory. Assistance from the Canada Department of Regional Economic Expansion permitted acceleration of this program and field work was completed in 1982. Information gathered by the program will form the basis for a management plan for future use of the resource.

Jan 1, 1984

By I. Kirman, B. Waters

World wide applications for nickel use will be summarized and examples of those uses given. Nickel products are critical to many important aspects of modern society. These products are just as important for modern China as they are in other parts of the world. It is argued that future pattern of nickel use in China should be expected to be very similar to that in the rest of the developed world. Total use of nickel in products in China is already very large. In 2004, it was the largest market for stainless steel (nickel containing) in the world. A survey of Chinese stainless steel applications will be presented. Current high nickel prices have revived speculation about substitution, particularly for nickel containing stainless steels. The presentation will discuss some of the complicating factors that need to be taken into account when considering substitution. These factors are as valid in modern China as they are in other developed economies. Recent substitution efforts and the reaction to them will be examined. The Nickel Institute position regarding appropriate application of the various grades of stainless steel will be discussed. Price-motivated substitution in China, and elsewhere, will occur but it is argued that the extent will probably be limited.

Jan 1, 2005