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By A. E. Cameron

The curve of coal production in Nova Scotia over the past forty years shows a definite maximum reached in 1913. Continued production to this maximum will require a greater tonnage per man-day, and this means there cannot be any increase in total man power used in the operations. There are still large reserves of coal but much of it will require washing or beneficiating to make a usable product. By-product recovery based on the present product ion is relatively satisfactory. Further development of secondary industries requires adequate markets for the bulk materials produced by the processing. It also requires access to other raw materials as well as markets for the principal product of the operations. Scientific investigation and research are needed to prove the quantity and value of lower grade or poorer quality coals, and methods for their recovery and utilization. Economics of further processing of present and future production must be investigated beforehand, if a successful development is to be assured. Such development cannot be expected largely to replace present markets. Production of coal for genera l use must continue to form the major function of the coal industry of the Province. Costs per ton must decrease, or subsidies or other assistance must increase, if the industry is to survive. Costs of investigation and research and costs of capital outlay for further development muse be met.

Jan 1, 1944

By M. T. Shehata, R. W. Revie, M. Elboujdaini

Environmentally assisted cracks in linepipe steels are initiated either as a result of stresses in combination with environmental effects, as in stress corrosion cracking (SCC), or as a result of trapped hydrogen in the steel, as in hydrogen-induced cracking (HIC). To understand better the mechanism of the crack initiation process, key metallurgical and environmental elements that can affect the cracking phenomena were investigated and are reviewed in this paper. The complexity of both cracking phenomena results from the dependence of SCC and HIC on multiple metallurgical, mechanical, and environmental parameters that may all influence both crack initiation and propagation; e.g., composition, microstructure and non-metallic inclusions in the steel, applied stress, water chemistry in the field, and ionic concentrations in the groundwater near the pipe surface to name a few for SCC. In addition, for HIC phenomena, one can add the concentration of H2S in the fluids transported in the pipe as well as concentration of CO2, pH, etc. In this paper, cracking of linepipe steels is analyzed critically, with particular attention to the crack initiation process. The paper is divided into two parts: The first part covers SCC and the second covers HIC.

Jan 1, 2005

By A. Makinen

There is an increasing trend between increasing consumption of water and the production of metal concentrate. Along with this trend we see that ore grades are declining and getting more complex to concentrate around the world. This will not only complicate processing but also generate new requirements for the management of water and waste streams on mining sites. The mining industry is a large user of water and its water consumption is growing rapidly. The processing of lower quality ores requires greater volumes of water. For these reasons, the need for efficient use of water and water management at mine sites is becoming more urgent. The perception of water in the mining industry has changed from thinking about it only in terms of "water treatment" to actually seeing it as a valuable resource, a resource that needs proper management. This resource management needs to involve various aspects, such as optimizing water usage of the entire mine or concentrator site, minimizing fresh water usage, minimizing or eliminating waste generated in water treatment and implementing practices for water reuse and water recycling. This paper presents trends and new developments relating to waste and water management in the mining industry.

Jan 1, 2015

By T. Iwasaki

This paper points out two key elements in resource trade in general and the Canada-Japan relationship in particular. The first is that the advanced countries have a more important role than one would expect in the supply of resources in world trade. Canada 's dual role as a major resource supplier in conjunction with an advanced economy will continue to increase. The second point is the heavy reliance on foreign resource supplies in some advanced economies, particularly in Japan. Finally, as regard the future of the Canada-Japan economic relationship, particularly .in resource development, it is suggested that trade could be enhanced by an accelerated exchange of various types of resources between the two countries. These include natural resource commodities as well as the more abstract capital, technological and human resources.

Jan 1, 1978

By M. J. Davie, D. S. Ross

"The successful design of a new mine water pumping system is in part dependent upon the accuracy with which the operating conditions can be forecast. This paper outlines the data which should be obtained on water quantity and quality. Methods of modifying the quality are also discussed. Some pumping systems for disposal of sludge are described, citing operating examples. The various types of mine dewatering pumps are described in terms of design characteristics as they affect operating efficiency and installation and maintenance costs. Piping system parameters are outlined. Finally, a hypothetical case study of pumping from a depth of 3,000 ft is assessed, with particular reference to capital costs.IntroductionMany mine operators would agree that the pumping system usually receives a low engineering priority during the design stage, and as a consequence causes some of the most frustrating problems during production. For a ""dry"" mine (up to 200 gpm), design of the pumping system may indeed be simple, but outside of the potash industry such mines are not common. For ""wet"" mines, the pumping system is important because it significantly affects the initial capital and on-going energy costs of the mine and, in the area of sludge disposal, the working conditions and production costs. Indeed, a failure in the pumping system usually has serious, and sometimes disastrous, consequences.The intent of this paper is to outline the factors which should be considered in the design of a pumping system and to describe the types of pumps used in mine dewatering and relate them to practical operating systems."

Jan 1, 1980

By The Staff

"THE Wabana iron ore mines, owned and operated by the Dominion Steel and Coal Corporation, Limited, .are on Bell Island in Conception bay, on the east coast of Newfoundland. Mining began on surface in 1895 and, although open-pit work is still done on a small scale, the entire output may be considered to•be derived from extensive submarine workings. In 1958 the average daily production of hematite ore was close to 12,000 tons, almost all of which was concentrated in a heavy-media plant. SUMMARYThe character, occurrence, and extent of the submarine bedded deposits enabled early operators to meet prevailing market demands with the minimum attention paid to exploration. Mechanization of the mine and the pressure for sustained high tonnages since 1955 have emphasized the importance of an expanded exploration and development programme.A serious handicap has been the impossibility of utilizing normal diamond drilling methods to explore ore conditions in advance of mining faces. Drilling between tl1e bedded zones has been done but the major difficulty has been to delineate ore reserves in the lower bed, which has the greatest ore potential of the three mineable seams."

Jan 1, 1960

By Thomas. L. O.

Apart from a few sketches and incomplete maps, mainly topographical, and one or two detailed maps of placer-creeks, there is little information on the topography and geology of most of the country adjacent to the sections of the Alaska Highway in the Liard River area, particularly that part east of Kechika river. In 1943, the Geological Survey of Canada made a recon-naissance from Fort Nelson clown the river of that name to the Liard, thence up the latter to Hell Gate, and also up Beaver river for a distance of fifty miles. The whole of the area covered was found to be underlain by sedimentary rocks, not a single igneous dyke being seen. The British Columbia Department of Mines began reconnaissances near the highway both in and north of the drainage basin of Prophet and Muskwa rivers with a view to finding structures favourable for the accumulation of oil. In Liard River valley near the mouth of Smith river and at intervals from there clown to Devil' s Portage occur warm springs whose character and origin are not definitely' known, since they have not been investigated (21, p. 38A). Similar springs are said to occur at several localities over a broad belt extending from Muskwa river across the Liard to the Nahanni River country (26, p. 11). On Liard river below the mouth of Dease river, stratified sands, gravels, and clays of Pleistocene (?) age are constantly met with and in one or two places are underlain by sandy clays. The distribution of the latter, however, is very limited in the section cut by the river west of the Rocky mountains. The only range of these mountains that reaches the Liard is the high limestone ridge which approaches the mouth of Vents river from the southeast and then almost vanishes a few miles to the northwest of it (27, pp. 43-45). In general, the ranges of the Rockies in the area under consideration have been but little explored, but they are undoubtedly very largely sedimentary and, with the exception of some volcanics and intrusives on their western flanks, are probably almost entirely so. Unlike the high, deeply incised ranges in southern British Columbia, they dwindle in elevation north of Terminus mountain to low-wooded ridges separated by wide swampy valleys, and practically lose their identity between it and the Liard. The foothills, which, along the Liard, have a width of 38 miles (from near the mouth of Trout river to Hell Gate) are composed of a great series of alternating shales and sandstones, with some limestones, all folded closely together, which resemble those found in the foothills farther south (27, pp. 50, 19-20).

Jan 1, 1944

When underground extractions occur beneath or in close proximity to valleys and other forms of irregular surface topographic features, the observed vertical subsidence at the base of the valley is less than that would be expected in flat terrain, while the valley sides are observed to move inwards towards the centre of the valley. The reduction in subsidence at the bottom of the valley is referred to as upsidence and the convergence of two sides of the valley is termed valley closure. Research coupled with mining experience over the past few decades in Australia has identified valley closure subsidence as being very real and quite significant part of non-conventional subsidence effects, which always have adverse effects on natural features, with risks to water flow and aquatic ecosystems. In this paper, we describe a threedimensional numerical modelling approach to investigate the geomechanical mechanisms which cause the valley closure subsidence behaviour, using distinct element computer package 3DEC. The calibrated models can accurately predict subsidence and horizontal displacements, and they are subsequently extended to specifically study the effect of a series of mining geological and topographical factors on valley closure subsidence phenomenon, by developing a range of hypothetical scenarios. Previous analyses carried out using a two-dimensional numerical modelling technique have identified the potential parameters that affect the valley closure subsidence, which mainly include longwall position, horizontal stresses, valley sloping angle, and valley shape. Further three-dimensional analyses regarding the relationships between the major factors and valley closure subsidence are discussed in this paper. The results have significant implications with regard to both the underlying mechanisms that lead to this nonconventional subsidence behaviour, and how these should be incorporated in future valley closure subsidence prediction and mitigation of its impacts on natural features.

Jan 1, 2015

By R A. Stevenson

The purpose of this paper is to outline a recent development in ground fault protection. The paper deals with the A problems of both grounded and ungrounded systems, with regard to hazards to personnel and equipment, and shows that the increased sensitivity and speed of operation of this new detector results in increased safety to personnel and reduced stresses on equipment, and permits the detection of leakage currents before they become serious faults. The detector can be applied to all distribution systems, either A.C. or D.C., up to 15 kv., and the detector itself can be tested at regular intervals without interrupting line circuits. T HERE is always controversy among engineers as to whether distribution systems should be grounded or ungrounded. There are many experi-enced engineers on both sides of this controversy, and each have valid reasons for their choice

Jan 1, 1964

By S. Steinlechner, G. Schneeberger, J. Antrekowitsch

Due to always getting stricter environmental legislations as well as increasing land filling fees the efforts for treating residues from metallurgy are continuously increasing. In case of filter dusts from metallurgical industry, the high zinc bearing electric arc furnace (EAF) dusts or also dusts from secondary copper industry are important sources for the recovery of secondary zinc oxide. Because of low capacities for secondary zinc concentrates (like Waelz oxide) in primary zinc metallurgy, the upgrade of such concentrates to a quality that meets the requirements of high quality (technical) zinc oxide becomes more and more important. This would open the opportunity to break into new markets and use it for example directly in electrolytic galvanizing. Therefore this paper will summarize possibilities for an elimination of halogens from secondary zinc oxides. Furthermore selective volatilization trials, with a synthetic mixture according to the analysis of Waelz oxide, were carried out to remove impurities to achieve an upgraded product quality.

Jan 1, 2011

By P. Au, R. Kearsey, D. Y. Seo, Patnaik. P. C.

Three nickel based superalloys (7.5%Cr+5%Co+2%Mo+1%Ti+5%Al and Ni balance (wt%)) containing different amounts of W and Re were produced in the single crystal (SX) condition utilizing the Bridgman casting process. First, the effect of different levels of Re, and W on chemical microsegregation were investigated by EPMA quantitative analysis, and eutectic phase fraction analysis. Second, in order to investigate the effect of these refractory elements addition on oxidation behaviour, isothermal oxidation testing of the SX nickel based superalloys was conducted at 1000°C for 277 hours under 3 ppm moisture content of air in a thermogravimetric analyzer (TGA). All three SX nickel based superalloys revealed an excellent SX solidification structure with a common primary dendrite arm spacing of -250 µm and a large fraction of ?/?' eutectic located between the secondary dendrite arms. From the average EPMA compositional results, with the exception of Ni, elements such as Cr, Co, Re, Mo, and W all tended to segregate towards the dendrite core during solidification, while Al, Ti, and Ta were present in greater quantity in the last liquid phase to solidify, which resulted in large eutectic ?/? ' phases to form within the interdendritic regions. As the nominal level of Re increased, microsegreagation of Re, W, Cr and Mo increased, indicating that Re had a much greater influence on partitioning behavior compared to W. Figure la shows the specific mass gain as a function of exposure time for each alloy. An alloy with 2wt% of W and Re (Alloy B) exhibited less weight gain compared to two other alloys with either higher content of W or Re (Alloy A and C). Microstructural and compositional analyses of oxidized samples were conducted using SEM and EDS. Figure lb shows the typical surface morphologies of the oxidized Alloys A and B. It is evident that more oxide nodules (indicated by arrows in the figure) were presented in Alloy A. It is speculated that the amount of these nodules was responsible for more mass gain in Alloy A compared to the two other alloys. From the examination of the longitudinal section of the oxidized samples as shown in Figure 2, for Alloy A, nodules actually penetrated deep into the material. For Alloy B, however, a relatively uniform and continuous oxide layer was developed and deeply attacked areas were not observed. It was also found that preferential oxidized regions were located at the area between the ?/?' eutectic phase and the dendrite arms where the concentration of refractory elements was relatively high. Therefore, it is plausible that the oxidation kinetics of these alloys is related to the extent of microsegregation.

Jan 1, 2004

By D. S. Case

"Following a brief explanation of the land arrangements under the Alaska Native Claims Settlement Act, this paper will examine both a mineral exploration agreement and a mining development agreement negotiated between two large mining companies and two different Alaska Native institutions. One of the institutions is a village corporation involved with an exploration agreement and the other is one of the Alaska Native regional corporations, which is party to a mining and development agreement with Cominco Alaska for the development of the Red Dog lead and zinc mine.Special attention will be given to the factors to be considered when dealing with small aboriginal owners with few resources in the context of an exploration agreement, including development issues which must be considered early in the process. The paper will also discuss the unique royalty and taxation structures developed for the Red Dog Mine Agreement as well as environmental issues. The paper will also consider the ways in which the cultural and differing economic interests of an aboriginal owner and a large mining company have been accommodated in the both the exploration and development agreements"

Jan 1, 1998

By A. L. McAllister

"MASSIVE sulphide deposits are found in two areas of New Brunswick, the St. Stephen area and the Bathurst-Newcastle area. In both, the geology in the immediate vicinity of the sulphide bodies is largely inferred from drilling results as outcrop is not plentiful and is, in fact, almost lacking in most places. With few exceptions these deposits have not been explored by underground methods. Consequently much of the. detail on the geology will only become known over a period of years as economic conditions make mining feasible.Much of the information contained in this paper has been supplied directly by company geologists. As a result of the number of contributors, some confusion of nomenclature bas to be anticipated. Cross-sections and plans of the individual deposits are, in most cases, as supplied by the companies concerned. Most of the interpretations are the responsibility of the author."

Jan 1, 1960

By Seong-Taek Lim

Recently, 7xxx aluminum alloys have been evolved into new variants for thick semiproducts which have low amount of 2nd phases and low quench sensitivity. Commercial 7xxx alloys, especially in the thick forgings made of big ingots, often entail microstructural inhomogeneities and concurrent poor mechanical properties due to limited heating ranges and slower quench cooling. In this study, high strength aluminum alloy 7175 and 7050 are adjusted as an attempt to control the equilibrium phases (M-, T- and S-phase) to have optimum microstructure for the thick forging applications. The effects of the relative content of (Zn, Mg, Cu) on the evolutions of the coarse equilibrium phases, hardening response and resultant mechanical properties are investigated. Equilibrium phases (M,T,S) are evolved depending on the constitutional effect, primarily the change of Zn:Mg ratio, and cooling rate following solutionizing. The formation of the T- and S-phases is effectively controlled, and M-phases are homogeneously precipitated in the adjusted (dilute and high Zn:Mg ratio) alloys. It provides extended heating range and lower quench sensitivity than conventional alloys. The attempts ensure the microstructural homogeneity and improved properties, and is expected to be uniquely applicable in 7xxx thick forgings.

Jan 1, 2004

By T. Billotte, G. Tirand, J. Zollinger, V. Robin, B. Rouat, D. Daloz

The grain structure prediction of metallic alloys during a welding process is often an issue. In addition to the welding parameters and the alloy nominal composition and properties, the base metal grain structure and chemical homogeneity also play an important role in the formation of the final microstructure. In this paper intensive characterisation of solidification structure in gas tungsten arc welding of Ni base alloy 600 are described. It is shown that in transverse section of the weld, while the grain structure shows some texture following constrained solidification growth, grain density in the weld is similar or greater than grain density in the heat affected zone. This suggests that simulation of the welding structure needs, in order to be predictive, to take into account : epitaxial growth, secondary nucleation events and 3D growth inside the weld pool.

Jan 1, 2015

By C. DeLong

"The Mt. Milligan porphyry copper-gold deposits are in central British Columbia, 155 km northwest of Prince George. Mineralized outcrops and float were discovered in the Mount Milligan area by prospecting. The most recent discoveries, which utilized lithogeochemistry, were in 1983. Areas containing the outcrops and float then were investigated by geological mapping, soil and lithogeochemical sampling, ground and airborne geophysical surveys, trenching and diamond drilling. This work led to the discovery of the Mt. Milligan Main deposit in 1987 and the Southern Star deposit in 1989. Extensive diamond drilling continued until 1991 and delineated a measured and indicated resource of 299 million tonnes grading 0.45 g/t Au and 0.22 % Cu from the combined deposits.The Mt. Milligan deposits lie within the Early Mesozoic Quesnel Terrane and are hosted by porphyritic monzonite stocks and adjacent volcanic rocks of the Takla Group. The Mt. Milligan Main deposit is centred around the MBX stock and Rainbow dike, and the Southern Star deposit around the Southern Star stock.Potassic alteration is extensive within the stocks and in volcanic rocks adjacent to the MBX stock and Rainbow dike. Propylitic alteration surrounds the potassic alteration and decreases in intensuy away from the stocks. Mineralization consists mostly of pyrite, chalcopyrite, lesser magnetite, and minor bornite, molybdenite and gold.Mineralogical zoning is well-developed within the deposits. A biotite-rich subzone forms the core of the potassic alteration zone and hosts most of the copper and gold. Numerous polymetallic veins lie within the propylitic alteration zone just beyond the limit of porphyry-style copper-gold mineralization."

Jan 1, 1995

By G. A. Moruzi

Two sulphide dust secondacy explosions have occurred in the mines of the SUdbury operations of Falconbridge Ltd. during the past 18 months. 'Ihe main similarity between the occurrences is that they both happened in vertical crater retreat blasthole stopes. A relatively high p:,v.tier factor was noted in both instances. other details are enumerated and examined, as well as some results of tests done by Noranda Research on company ore samples.

May 11, 1988

By G. Morin, F. Chiesa, B. Tougas, B. Duchesne, Jocelyn Baril, N. Giguère

"An aluminum A356 compressor impeller was sand cast using the Low Pressure technique. The casting was limited in size (170 mm in diameter, 1.2 kg in weight) and very intricate in shape thus making 3D mold printing particularly favorable; indeed, producing this part by the traditional pattern-core box route would involve mounting 12 cores inside the mold while stringent dimensional tolerances are required as the impeller blades are only 2 mm thick. Consequently the molds were produce on the X-One MFlex printer of Quebec Metallurgy Center - CMQ. A dozen castings were produced with different casting temperatures and filling times so that it was possible to assess under which conditions complete filling of the mold cavity would be achieved. Filling and solidification modeling allowed predicting misruns and metallurgical properties inside the A356 (AlSi7Mg04) casting.INTRODUCTION Recent advancements in additive manufacturing enable foundries to produce molds without the tooling (pattern and core boxes) necessary when conventional technology is used (Eyad, 2016). This is particularly advantageous when dealing with intricate shapes and/or when a limited number of parts must be produced within a few days rather than in 5 weeks. An additional advantage is gained when producing prototypes (Johnson, 2016) as changes are much less costly and time consuming when made on a numerical 3D drawing rather than on patterns and core boxes. 3D printing is normally economical for a small number of parts; however, if the part is not too big and very intricate in shape such as the part that will be studied in the present work, 3D printing can be economical even for an important number of castings to be produced. On the other hand, low pressure casting is a high integrity casting process in which the mold cavity is filled from the bottom via a transfer tube in which the liquid aluminum rises under the pressure applied at the surface of the melt as illustrated in Figure 1. The filling can thus be precisely controlled, eliminating the turbulence created when the mold is filled from the top (gravity casting). Also, the pressure applied on the melt during solidification results in excellent feeding of the casting when conditions of directional solidification are met. In the present work, the compressor impeller shown in Figure 2 will be sand cast by low pressure."

Jan 1, 2018

By François Robert, Rex Brommecker, Don S. Bubar

"The Orenada Zone 4 deposit is a small vein-type gold deposit occurring directly within the Cadillac Break southeast of Val d' Or in southeastern Abitibi Sub province. Mineralization is hosted by the Piche Group which, on the Orenada property, consists of talcchlorite- carbonate, chlorite-carbonate, and sericite-chlorite schists, derived from ultramafic volcanic, mafic igneous, and intermediate to felsic volcaniclastic rocks, respectively. All these rocks have been carbonatized.Rocks of the Pichi Group display a strong east-west, subvertical S1foliation, which is superimposed by asymmetric, intrafolial F2folds with shallow to moderate plunge to the east and to the west. F2folds are accompanied by an S2, subvertical axial planar cleavage, and are interpreted to result from dextral transcurrent shearing along sr.The Zone 4 deposit occurs within a large F2 fold, 60 m wide and plunging at 45 to the east, down to a depth of at least 300m. The auriferous zones consist essentially of zones of closely spaced, parallel quartz-tourmaline-albite-carbonate-arsenopyrite veins concordant to Sr these veins have been folded by the large F2fold and may pre-date the folding. A few discordant quartz-tourmaline-arsenopyrite veins, post- dating the F2 folding, also contain gold. Wallrocks adjacent to concordant veins have been carbonatized, albitized and contain significant amounts of tourmaline and arsenopyrite, with which gold is intimately associated.The Orenada Zone 4 deposit is a unique example of a deformed vein- type gold deposit, and exemplifies one of several types of association of lode gold deposits with folds."

Jan 1, 1990

By R. Loney, M. Militzer

There is a significant demand for new high strength steels with fine grain sizes for structural applications. One approach in this regard is to develop hot-rolled HSLA steels where refining the microstructure leads to increased strength levels, e.g. 700 MPa yield strength, that can be attained by suitable modifications of chemistry and processing. Here, an HSLA steel is investigated that contains 0.05wt%C-1.65wt%Mn-0.20wt%Mo¬0.07wt%Nb-0.02wt%Ti and approaches the above strength class. The ability to control and predict the mechanical properties of hot rolled steel depends strongly on the thermomechanical processes, which the steel undergoes. The final microstructure and, thus, the properties of the hot-rolled steel are a function of the austenite decomposition obtained during accelerated cooling on the run-out table and precipitation during coiling. The austenite-to-ferrite phase transformation under run-out table conditions has been investigated using a Gleeble 3500 thermomechanical simulator equipped with a dilatometer. The effects of cooling rate and initial austenite microstructure including the degree of work hardening on austenite decomposition kinetics and ferrite grain refinement have been quantified. Results show that grain refinement can be optimized by the presence of work hardened austenite and accelerated cooling. Based on the experimental results, a model is proposed to predict the transformation start temperature and the resulting ferrite grain size for run-out table cooling conditions.

Jan 1, 2004