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By Robert B. Parsons

"The last edition of Tax Notes expressed concern about two proposed tax changes in Finance Minister Paul Martin's 1995 budget that could have detrimental effects on Canada's mining industry. This month, Tax Notes expands on these concerns. This article is based on a paper that the author presented at ClM '95 in HalifaxIntroductionOn a global basis, there are more investment opportunities in the mining industry today than at any other time in history. Countries in Central and South America, Eastern Europe, the CIS, Central Asia, and Asia are competing aggressively to attract investment to all sectors of their domestic mining industries. Today, the demand for investment dollars exceeds the amount of dollars that are available for investment in mining. It is not surprising, then, that the established mineral producing nations are witnessing a decline in spending on exploration and development on their home turf, and an increase in spending in developing countries. In the context of a developed country such as Canada, there are two manifestations of the problem of declining investment: (I) Foreign investors are allocating more of their capital budgets to new opportunities in developing countries; and (2) Canadian juniors and seniors are spending proportionately more abroad. This shift in global spending patterns is the source of some concern for the future of Canada's mining industry, particularly because it is widely believed that the current rate of discovery of ore reserves in this country is too low to replenish depleting reserves.""Government bashing"" has always been a popular pastime in Canada. Invariably, this pastime has focussed, at !east in part, on taxation. In view of the intense competition that Canada faces on the global mining scene, it is important that the role of taxation in the decision-making process be kept in perspective. This paper seeks to put the role of taxation into perspective."

Jan 1, 1995

By J. S. DeLury

The last few years have been eventful ones for Manitoba in connection with mineral development. Perhaps the past year has been the most important of all. It is therefore a suitable time to review the mining situation in the Province. In order to obtain, in the following paper, a proper set ting from which to discuss the trend of recent developments, a brief review of the story of mining will first be given. This will include a summary of a few of the outstanding facts regarding prospecting, discovery, and operations in the several known metalliferous areas of the Province. Following this will come a more detailed description of activities during the past year or two. Special attention will then be paid to the outstanding enterprises, such a~ those associated with the names of Flin Flon, Sherritt-Gordon, and Central Manitoba, names which have been attracting the attention of the mining world to Manitoba. And last of all will be presented a brief summary of mineral production, which, so far, has largely been credited to non-metallics. HISTORICAL To aid a proper comprehension of the recent trend in mining, it is well not to lose sight of the history of development in the different metalliferous areas in Manitoba. This Province seems throughout to have been more or less dependent on mining interest excited by discoveries in the neighbouring province of Ontario. The first interest came as an effect of the Lake of the Woods mining boom, when small adjacent parts of Manitoba were prospected. Several discoveries were made, but no mining industry resulted.

Jan 1, 1929

By W. Graham

"IntroductionEFFLORESCENCE is herein considered to be any deposit of salts on the surface of a masonry structure that is brought from within or through the structure by capillarity and deposited by evaporation. Usually, efflorescence is white although green, yellow, and brown efflorescence is sometimes observed.The common white efflorescence almost always consists of sulphates of the alkali and alkaline earth metals and calcium carbonate, although sodium chloride is frequently present in structures erected near the sea shore.The first and most obvious result of the presence of soluble salts in masonry is the unsightly accumulation of these salts on the surface. This is particularly noticeable early in its life and is frequently fugitive ( 1), as much of the salt is soluble and is gradually washed away by rain. This removal can usually be facilitated by scrubbing; the structure with dilute hydrochloric acid.A more serious effect is the continuous accumulation of soluble salts as a result of ingress of sulphur acids in rain water or water from the ground. This may eventually cause spalling and disintegration by crystallization of salts in the pores of brick and mortar. An example of this type of failure, resulting from the crystallization of calcium sulphate, is discussed by Hardesty (2). Butterworth (3) describes similar failure resulting from •crystallization of magnesium sulphate."

Jan 1, 1954

By J. Fujioka, Y. F. Gu, C. Cui, D. Ping, A. Sato, H. Harada

"A new kind of cast & wrought (C&W) Ni-Co base superalloys named as ""TMW alloys"" are developed recently for compressor or turbine disks of gas turbine engines in High Temperature Materials 21 Project at National Institute for Materials Science (NIMS) in Japan. These Ni-Co base superalloys combine the characters of two kinds of y- y' two-phase alloys (Ni-base and Co-18at%Ti alloys) and have higher tensile strength and creep resistance than C&W UNDIMET 720Li superalloy."

Jan 1, 2006

By Y. Kashiwaya, J. Yagi, P. R. Austin

The problems of global environment and resources have become important issues in recent years, and the iron and steelmaking industry is requested to decrease energy consumption and carbon dioxide emission. The improvement of efficiency of ironmaking system is one of the countermeasures for these problems because more than a half of total energy input to the integrated steelwork is input to the ironmaking system. Various approaches to improve the blast furnace process have been made. The authors examined their performances through mathematical simulations of blast furnace operation, and confirmed the improvement of blast furnace efficiency under some operating conditions. The ironmaking system consists of various processes, and the materials and the energy are transported among these processes. Thus it is necessary to evaluate the efficiency of the novel operation of blast furnace based on the ironmaking system. In this study, the balances of material and energy on ironmaking system that consists of blast furnace, coke oven, sintering and hot stove processes were analyzed. The operation status of each process in the system was adjusted according to the results of the operation simulation of the blast furnace under novel operating conditions. The analysis clarified the effect of the blast furnace operation on the energy balance and CO2 emission of the ironmaking system.

Jan 1, 2015

By E. P. Wiechmann, J. A. Henríquez, P. E. Aqueveque, L. G. Muñoz, G. A. Vidal

"The original segmented intercell Optibar succeeded in reducing the magnitude and occurrence of short circuits. It also improved the specific energy consumption of the process. This paper expands the load current source concept introducing a triple segmented bar. This new bar adds immunity to dirt contacts and open circuits. Moreover, it further improves the standard deviation of current densities. As compared with industrial practices this development should accomplish an 8% specific energy reduction. Also, a plant implemented with BBS should be able to work with 12.5% higher process currents than Walker without compromising the operation.INTRODUCTIONIn 2011 the technology based on current mode was implemented at industrial scale. The success of this technology moved CIM Magazine (Lanktree, 2011) to write in the Jan 2012 issue an upfront story of this technological innovation. To cover the story, the technical reporter Graham Langtree was appointed by Peter Braul Editor of the upfront section. The article tells that “More than 40,000 tonnes of copper have been refined in a year-long test run of Optibar Inc.’s new technology at Barrick Gold’s Zaldívar copper plant in northern Chile. The new segmented intercell bars being used in the Compañía Minera Zaldívar refinery have slashed energy costs, reduced short circuits during refining and allowed the production of heftier, purer sheets of copper – gains that all promise to boost the plant’s margins. A copper refining tank house containing the cell circuits typically consumes 2,000 kWh of electricity to produce a single tonne of grade-A copper. Yet, monitoring the energy efficiency of the Optibar technology after increasing the weight of harvested copper sheets, the project’s engineers recorded a 92 kWh-per-tonne cut in energy consumption, a savings of 4.6 per cent. “Today, with the power prices we have, Optibar technology represents a potential savings for the whole plant of US$1.5 million per year,” says Robert Mayne- Nicholls, executive general manager of Barrick Gold’s Chilean operations.”"

Jan 1, 2012

By P. K. Kaiser, C. D. Martin, F. Amann

"This article focuses on the uniaxial compressive strength (UCS) of homogeneous and heterogeneous rocks. Critical factors impacting the UCS of rocks are reviewed and then separate assessments of UCS data from homogeneous and heterogeneous rocks are presented. The variability (coefficient of variation) of UCS test results for homogeneous rocks is found to be generally <25% while for heterogeneous rocks the variability is >35%. Failure mode variation is found to be the cause of the variability of UCS test results in heterogeneous rocks. Empirical engineering design methods that use UCS as an input parameter are discussed and suggestions are provided for selecting appropriate UCS values.INTRODUCTIONThe UCS is one of the most commonly used rock engineering parameters whether for rock mass classification or for strength determination. The mean UCS and its variability are often assumed to represent a reliable rock material property. For the reasons discussed in this article, UCS is rarely representative of the intact rock UCS. The UCS test simply records the collapse load during uniaxial loading of a cylindrical specimen. As suggested by many, the UCS is an index rather than a unique engineering parameter. The UCS is thus a proxy for rock strength which depends on the loading rate (e.g., Bieniawski 1967), specimen geometry (e.g., Hudson et al., 1971), specimen size (e.g., Bieniawski 1968), and many other factors. Furthermore, the UCS is not the same as the Hoek-Brown strength criterion parameter sci.There are differences in opinion on what is commonly considered to be ‘intact rock’. When sampling ‘intact’ pieces of core from drillholes crossing blocks of rock bound by block forming discontinuities, samples will be ‘intact’ but some samples will be veined, others will be damaged, and others will be neither. According to Hoek (1983), intact rock pieces are “the unfractured blocks occurring between structural discontinuities in a typical rock mass” and the sci parameter for intact rock is determined using the fitting procedure proposed by Hoek and Brown (1997) based on the data requirements outlined by Hoek (1983). Studies (e.g., Bewick and Kaiser 2014; Kaiser and Kim 2014) have shown that independently determined UCS and sci values for the same rock type are not equivalent. Thus, UCS data cannot be used as a replacement for sci."

Jan 1, 2015

By K. J. Fair, G. Van Weert, J. E. Schneider

"IntroductionCyanidation is the principal process for extracting gold from ores . Many primary gold ores, however, are partially or totally refractory in the conventional cyanidation process.Considerable success has been achieved with new gold leaching techniques, such as intensive cyanidation, pressure cyanidation, carbon-in-leach cyanidation, etc. These techniques however, do not offer substantial gains in gold extraction from refractory pyrites.The more drastic pretreatment processes such as roasting, chemical oxidation, autoclave oxidation, and bacterial oxidation all utilize oxidation to break down the structures of pyrite and arsenopyrite. This generally renders the gold amenable to cyanidation.Comparative cost studies indicate that the oldest commercial pretreatment method, i.e. high temperature roasting, is currently the least expensive option if the sulphuric acid can be sold. It operates with air at atmospheric pressure and is characterized by fast reaction rates. For an alternative hydrometallurgical con centrate treatment method to be competitive, it too should operate with air at atmospheric pressure and with fast reaction rates. The NITROX process meets these conditions."

Jan 1, 1986

Sherwood?s Minto Project ? High grade copper copper-gold deposit ? Yukon Territory, Canada ? Development underway ? Permitted ? Production by mid mid-2007 ? 40 40-50m lbs Cu plus Au/Ag by by-products ? Parallel exploration program underway ?Discover more high grade resources ?But what kind of deposit is it?

May 1, 2006

By Ralph W. Edie

"IntroductionTHIS PAPER presents some analyses of diabases from a number of metallogenic provinces in Canada and the United States. It is intended as a contribution to the literature on the genesis of mineral deposits associated with diabase.As it has been in the past, opinion today on the origin of the cobaltnickel- native silver and associated pitchblende type of deposit is sharply divided. Some geologists hold that this type of deposit is in some way genetically related to intrusive diabase; others are of the opinion that the deposits are related to granite. The controversy, like others of a similar nature, probably will not be settled satisfactorily for many years to come, •but in the meantime it is recognized that, with respect to most deposits of the type referred to, altogether too few facts are known for accurate conclusions on genesis to be drawn. To contribute in a small way to factual data on this whole .problem, the writer analyzed diabase from several districts in Canada in which deposits of the aforementioned type occur. For comparative purposes, the copper, cobalt, and nickel content of diabase from Cornwall, Pennsylvania, and of norite from the Sudbury basin of Ontario, was also determined.Insofar as is known, none of the analytical work undertaken had been previously carried out."

Jan 1, 1953

By M. Dupuis

In the present study, the heat balance of the Hirakud smelter aluminium reduction cell has been accurately assessed using only a surface thermocouple and a pyrometer, As it is well known that using a single linear or quadratic relationship to estimate the heat flux from the measured surface temperature does not provide the accuracy required to close the cell heat balance, this approach was not used in this study, Instead, the fundamental natural convection and radiation heat flux equations were used systematically for each measurement point, Practically, this means that the ambient air temperature and at least one ambient radiative temperature must also be known in addition to the surface temperature for each measurement point. Sometimes, the radiative heat flux could not be accurately estimated using a single ambient radiative temperature, In those cases, a more accurate estimation based on two ambient radiative temperatures and corresponding view factors has been used instead, It turns out that although at least three temperature measurements are required to estimate a single heat flux, it takes a lot less time to make those temperature measurements using a pyrometer than directly measuring the heat flux using an expensive heat flux meter, Furthermore, no loss in accuracy was detected when using this approach as the cell heat balance could be closed within 5%, the level of accuracy typical of cell heat balance assessment using heat flux meter.

Jan 1, 2004

By E. Poiate, P. R. Cabral, A. V. N. Santos, P. V. M. Costa, C. S. Amaral, A. M. Costa

This paper discusses the design of underground salt caverns, opened by solution mining, for the production of brine and storage of natural gas under high pressures. The caverns are located in the salt basin in Maceio City, Alagoas State, at the northeast region of Brazil. Special attention is given to the geomechanical structural design of the caverns using computer codes specially developed for the simulation of excavations in salt rock formations, considering validated constitutive creep laws under different initial stress states and temperatures. The behavior of sedimentary rocks intercalations presented in the salt layer is simulated using elastic-plastic models. The excavation of the caverns by solution mining is also simulated starting from a geostatic initial equilibrium state of stresses, with a unique formulation only implemented in these computer codes, without the need of the application of boundary stresses to the model in order to develop the initial state of stresses. These computer codes have being used in the design of several clusters of caverns for brine production used as raw material of Poly Vinyl Chloride (PVC) of the Chemical Industryin Brazil. These computer codes and methodology were also applied to the design of the underground conventional potash mine in the state of Sergipe, overlying tachyhydrite and carnallite with very high creep strain rate. They have also been used in the design of the pre-salt oil wells through thick layers of stratified salt rock in Santos Basin, for the exploration and production of the pre-salt reservoirs in Brazil. The constitutive creep equations implemented in the codes are based on a double mechanism creep law. The creep constants adopted in the simulation are taken from a previous investigation carried out on an experimental panel of the potash mine, considering the stratified geology with different salt rocks of the basin where the mine is located. These constants were also obtained by lab tests under different confined and differential stresses and temperatures.

Jan 1, 2015

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 W. W. Bake

INTRODUCTION IN IN JUNE, 1943, the main pillars of the Beattie Mine glory hole failed, allowing over a million yards of wet clay and debris to flow into the mine, completely filling all workings to within seventy feet of the 3rd level. The resulting Job of clearing these workings and rehabilitating the mine represents a unique and hazardous operation, seldom, if ever, previously encountered in Canadian mining. The purpose of this paper is to describe one phase of this operation -that of cleaning and rehabilitating the mine from the 6th to the 9th level -to outline briefly the events which led up to this work and to describe the techniques and costs involved. It will be noted that such costs, methods, and performance figures as are dealt with in this paper refer only to work in the internal shaft and adjoining workings from the 6th to the 9th level, previous work having been done under other supervision and management. The Beattie mine is in Duparquet township, northwestern Quebec, twenty miles northwest of the town of Noranda and twenty-three miles southeast of the town of La Sarre. The mine and the town of Duparquet, which it?supports, are accessible by highway from Noranda throughout the year. Production at the Beattie mine began in May, 1933, and up to June, 1943, twenty-one million dollars in gold and silver had been recovered from five and a half million tons of ore.

Jan 1, 1951

By Roorda H. J, R. R. Saddington, Curlook W

THE copper-nickel sulfide ore deposits of the International Nickel Company of Canada, Limited contain the minerals pyrrhotite, pentlandite, and chalcopyrite. In the extraction of the nickel, copper, and iron, much of the processing involves oxidation of the metals as well as sulfur. Roasting plays a predominant role at several stages in the operations which prepare the constituent metals for refining. Copper, nickel and iron concentrates of various grades, ranging from low-grade nickeliferous pyrrhotite to high-grade nickel sulfide, must be partially or completely oxidized. Figure 1 shows the main points at which roasting is conducted at INCO. Roasting experience at INCO dates back to the time when lump ore was partially roasted in heaps. It has progressed through single hearth roasters, sinter machines, multiple-hearth roasters, flash roasters, and more recently has centered on the development and utilization of fluid bed roasters. The primitive, slow, and inefficient method of heap

Jan 1, 1961

By C. Hudson, D. Tremblay, A. Frey

"A discussion of the design, challenges and successes associated with the commissioning of the gravity recovery circuit at Canada’s newest open pit gold mine - Atlantic Gold’s Moose River Consolidated Project in Nova Scotia, Canada is presented. An overview of the project, its historical significance and overall flowsheet is provided with special focus given to the design and selection of the gravity circuit equipment including the scalping screen, gravity concentrators and the novel intensive leaching technology selected for the project. The performance of the gravity circuit is benchmarked against the feasibility study process design specifications and the outcomes are discussed. Challenges encountered during commissioning are also presented, including the use of third-party automation and the effects of screen sizing on overall gravity circuit performance. Mechanical modifications made to the Sepro Leach Reactor for the Moose River project are also discussed. A detailed technical review of the mechanical and operational aspects of the Sepro Leach Reactor is provided with key operational data on leach times, recoveries, reagent usage, solid-liquid separation, pregnant solution quality and its influence on bullion purity.INTRODUCTION Atlantic Gold Corporation’s Moose River Touquoy Mill in Nova Scotia, Canada was commissioned in the fourth quarter of 2017 with commercial production declared in March of 2018. The 2 Mtpa process plant uses a conventional, gravity-CIL process. This site was previously mined in the 1870s. Interest waned in the early 1900s but resumed in the 1930s and the mine was brought back into production in 1935 until an underground mine collapse in 1936. This mining district became famous after CRBC radio commenced a ground breaking, around the clock, broadcast of the rescue operations. Over 100 million people listened to the broadcast from Canada, the United States and the United Kingdom. These broadcasts changed radio, transforming it from a medium for music to on the spot, breaking news reporting. The mill was constructed by Ausenco on a fixed price EPC contract in the historic Moose River gold mining district, 95 km north-east of Halifax by road. The mill will process ore from the adjacent Touquoy pit for the first 5+ years of operation; after the Touquoy reserves are exhausted, the mill will process ore trucked 37 km from the Beaver Dam deposit for an additional 5 years."

Jan 1, 2019

By H. Lachmund, R. Bruckhaus

At Dillinger Hüttenwerke/Germany steel production of grades for linepipe applications especially for sour service has a long tradition. The BOF process after replacement of the vessels is optimized by a newly developed lime addition model and variations in lance tip geometry. Equipped with three state-of-the-art VOD tank degassers metallurgical requirements of lowest contents of e. g. sulphur, nitrogen and hydrogen can be achieved. Three continuous casting machines of vertical bending type with solid core even improve already high levels of cleanliness. The vertical part corresponds to the metallurgical length of 12 to 15 m and therefore assures a maximum of cleanliness after solidification before bending. Slab thickness up to 400 mm can be produced with model controlled dynamic soft reduction. The accurate alignments of the casters assure minimized segregation and microporosity. Surface and internal cracks can be avoided by special cooling, bending and straightening strategies.

Jan 1, 2005

By P. G. Thornhill

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

Jan 1, 1961

By R. C. A. Thurston

AT A FATIGUE SESSION organised by the A.S.T.M. in 1949, R. E. Peterson presented a brief introductory paper ( 1) in which lie referred to a discussion on the fatigue of metals which took place in England in 1849, and then proceeded to review some of the subsequent researches concerning the mechanism of fatigue. In the course of the review, he discussed metallograpl1ic studies with single crystals and polycrystalline materials, studies with X-ray methods, and the application of the electron microscope. During that hundred-year period considerable progress was made toward a better under-standing of the nature of fatigue, although it is probable that even greater attention was directed to the more practical aspects of the problem, such as the effects of notches, temperature, corrosion, surface treatment, residual stresses, and so on. Since then there has been an appreciable acceleration in the tempo of the fundamental work, partly influenced by the rapid development of the theory of dislocations, with the result that our knowledge of the mechanism of slip, the initiation of fatigue cracks, and their subsequent propagation, has still further advanced, although it is by no means complete as yet. The present paper is an attempt to out-line the more recent developments in these basic studies, to correlate them when possible, and to draw attention to those directions in which research might profitably be pursued.

Jan 1, 1957

By J. Stachulak

In recent years more emphasis has been placed on the control of nitrogen dioxide (NO2) emissions from mining diesel equipment. Worldwide, diesel engine regulations to control emission and protect the environment are also driving the development of the diesel engine technology to reduce oxides of nitrogen NOx (Nitric oxide, NO + NO2). NOx are toxic gases produced in mines during the operation of diesel equipment. Most of the diesel equipment used in underground operations are equipped with Diesel Oxidization Catalysts (DOCs) designed to reduce carbon monoxide (CO) and hydrocarbons (HC). The effects of DOCs on NO2 production from diesel powered equipment is not well understood. DOCs do not alter NOx concentration, but may promote the oxidization of engine exhaust NO to the more toxic NO2, thus increasing the undesirable NO2 exposure of workers in the mine environment. In 2012, the ACGIH reduced the NO2 TLV concentration value from 3 ppm to 0.2 ppm. Vale and CanmetMINING have been involved in several research projects to reduce diesel emissions exposure to workers. One aspect of the current program is to determine the effects of in-use DOCs on NO2 production. Several in-use DOCs taken from mining equipment were selected for testing in the laboratory using ISO 8178-C1 and mine LHD transient test cycles. The paper presents the laboratory test results and effects of DOCs on NO2 production. The results indicate significant reductions in CO concentration, by over 77%, while increases in NO2 varied from 46% to 315% based on the ISO 8178-C1 8-mode steady state test cycle. The mine LHD transient test cycle showed the same pattern, although the magnitude of CO reduction was less. Consequently, it is recommended the use of only those DOCs that have been properly evaluated and shown not to significantly increase NO2 emission in the environment be used on mine equipment.

Aug 1, 2013