Search Documents

By P. Lafleur

All indications point to a growing market for thermal coal in Japan as part of the country's current energy policy formulation process. The Ministry of International Trade and Industry forecasts imports of 16 million tons a year in 1985 and 40 million tons in 1990-a twenty-fold and forty-fold increase over the present level. This potential reflects Japan's over-all serious and increasing concern for security of energy supplies and its resultant need to seek alternative sources. Nuclear power will be the main alternative source, but, because it is expected that its development will be slow, imported thermal coal will assume greater importance. Canada, with large resources of all types of coal, could fill a portion of this market. Thermal coal could come from specific thermal coal developments or from metallurgical coal mines, which usually produce a certain amount of coal not amenable to coking, but suitable for power purposes. However, penetration of this Japanese market by Canadian thermal coal will depend on the resolution of a number of problems. On the demand side, siting, environmental aspects, the need for a coal unloading and trans-shipment centre, and the added cost of installing coal-fired stations could be major constraints. Although Canada has ample high-quality resources, any new development tied to the Japanese market will require improvement in prices to cover the high costs associated with transportation, the construction of new mines and the provision of new infrastructure.

Jan 1, 1979

By W. Banda

"Trial application of air decks on a production shot improved fragmentation (32% reduction in x50). Empirical fragmentation models and digital image processing software were used to estimate fragment size distribution of the blasted muck pile. The x20, x50, and x80 passing fractions, and top size were 42, 265, 683, and 1,455 mm, respectively. Air-deck application reduced explosives load in blastholes, lowering total charging cost by US$20/hole (15% decrease) and the powder factor to an average of 0.86 kg/m3 (12% decrease). Blast results were 443,624 t of blasted material from the block (90% of total muck pile) was smaller than 900 mm.RÉSUMÉ L’application pilote de trous d’air dans le cadre du coup de mine effectué pour commencer la production a amélioré la fragmentation (une réduction de 32 % des x50). Des modèles empiriques de fragmentation et un logiciel de traitement numérique des images ont permis d’estimer la composition granulométrique des fragments du tas de déblais abattus. Les fractions de passé de crible de x20, x50, x80 et la dimension supérieure étaient représentées par des dimensions respectives de 42, 265, 683 et 1 455 mm. L’application de trous d’air a permis de diminuer la charge d’explosifs nécessaires dans les trous de mine, réduisant ainsi les coûts totaux de chargement de 20 $ US/trou (soit une réduction de 15 %) ainsi que le facteur de chargement (facteur poudre) à une moyenne de 0,86 kg/m3 (soit une réduction de 12 %). Les coups de mine ont résulté en 443 624 tonnes de matériaux abattus du bloc (soit 90 % du tas de remblais total) mesurant moins de 900 mm. INTRODUCTIONThe main objectives of production blasting are to achieve optimum rock fragmentation and to minimize overall production costs. Because blast fragmentation significantly affects the profitability of a mine, blasting is the first step of the size reduction in mining: An optimum size distribution is required to maximize the performance of mining and subsequent milling processes. If the fragmentation size distribution can be modelled and controlled, operations performance will improve. Blast fragmentation modelling is important in mineto- mill optimization: It allows the estimation of blast fragmentation distributions that can be modelled in downstream mining processes to determine the optimum blast design."

Jan 1, 2018

By Gulshan Kumar Pradhan, Yogendra Pratap Singh, Dhawanm Nikhil

"Potassium (K) is one of the essential elements for the growth of plants and thereby for humans. In fertilizers, potash demand has been steadily increasing at ~3.5% annually. Water soluble potash deposits are rare and highly localized. India is neither present on the world potash production map nor it has adequate potash rich rocks. The K-bearing minerals are recovered either by using conventional underground mining methods or though solution mining methods. India possesses a vast resource of silicate rocks such as glauconitic sandstone and Feldspar. These rocks are basically a group of alumino silicate of potassium, sodium and calcium (K2O%: 5-12, Na2O%: 3-10%, SiO2%: 52-65, Al2O3%: 15-20, Fe2O3%:, 5-7 and MgO%: 2-3.5).The K extraction from silicate rocks has received little attention probably due to the slow release, the locked structure of alumina-silicate minerals, and the unavailability of appropriate economic processes & their know-how. In fact due to this India imports all of its potash demand (about 3.5 million tons per annum) from different countries.In the present work, an attempt has been made to identify the structural and chemical alteration of desired K mineral phase in silicate rock (~K2O%: 10.5, Na2O%: 2%, SiO2%: 55, Al2O3%: 19, Fe2O3%, 5-6, MgO%: 2.5) under different conditions such as acid leaching, thermal treatment and chemical processing. Different treatments are aimed to increase K availability which is related to the modifications in mineralogical composition. The modifications in the feed sample and treated samples are studied through SEM-EDAX, XRD, EPMA and optical microscope. With the combination of treatments, it is possible to extract more than 90% K and the formation of sylvite phase (water soluble) confirms the dissolution of potash values."

Jan 1, 2016

By Leslie McHattie

?Intelligent mine? conjures up a futuristic image of unmanned extractors and loaders working in harsh conditions in a remote lunar landscape. The promise of increasing mine fleet productivity and solving the problem labor shortages in mining regions can certainly be achieved today through remote controlled extraction and automated hauling. The technology is available and it doesn?t seem to be so much science fiction when Google?s self-driving cars hurtle down the freeway. ?Intelligent mining,? on the other hand, implies the application of information technology at every phase of the mining value chain, from exploration and geological modeling to equipment, operations and maintenance, and logistics and transportation. These are really industry-specific, enterprise-class software solutions focused on using information technology to support the business processes of mining and make them more efficient and effective. Overlaying the physical world with the digital or virtual world enables us to model and simulate our assets, giving us the ability to effectively design, build, and ultimately optimize the performance and reliability of our assets throughout the lifecycle. The digital asset, often a 3D model, is created initially during the engineering and construction phase, and is handed over to the operator before the mine goes into operation. Combined with geospatial or geographic information systems, the operator has a complete digital representation of the physical world, which forms the foundation for risk and performance management, along with compliance and regulatory reporting. Laser scanning and positioning technology can be used to create point clouds ? information models consisting of millions of data points ? which enable the visualization and representation of the ?as-operated? reality. But consider that once the mine is in operation, it throws off an endless stream of data in the form of performance and condition data from sensors and monitoring devices on fixed and mobile assets through networks, servers, and services. This ?big data? can be processed and analyzed to spot trends, help predict events, and formulate reliability strategies as early as the design stage (e.g., reliability-centered design). ?Intelligent mining? implies that massive amounts of data augment the reality of the physical mine, plant, and equipment. This embedded intelligence can be used to optimize operational efficiency, increase asset availability and utilization, improve safety and environmental integrity, and maximize return on investment. Lastly, the sweet spot for intelligent mining is seen in the convergence of consumerization and industrialization. The application of ?consumer? technologies that we use every day on our iPhones and Android devices, such as cameras, motion sensors, and positioning in an industrial context, are producing ?immersive? experiences. Overlaying the digital world on the physical world and connecting them accurately through intelligent positioning results in ?intelligent infrastructure,? which is safer and more sustainable. Bentley Systems works with many mining companies and engineering, procurement and construction companies involved in all aspects of mining infrastructure development. In fact, 10 of the top 20 mining companies ranked by market capitalization are users of Bentley software, including all of the top five. In addition, Bentley provides software solutions to the world?s leading engineering, procurement, and construction companies, as well as owner-operators, who design, build and operate the world?s infrastructure. Bentley?s solutions for mining and resource extraction industries help increase the efficiency of capital projects associated with the design, procurement, and construction of mines and processing plants, as well as the operation and maintenance of mining fleet and equipment.

Aug 1, 2013

By J. S. Fox

"Besshi-type Cu-Zn (-Ag-A u ± Co) deposits are tabular, stratiform volcanogenic sulphide bodies which are usually associated with mafic volcanic rocks of oceanic or intra-plate geochemistry, but which can also be found locally with ultramafic volcanics or subvolcanic mafic intrusions. A thick sequence of continentally-derived clastic sediment usually encloses both the mafic volcanics and the ore. Besshi-type deposits form subaqueously, in epicratonic rifting environments, more-or-less proximally, and as a result of hydrothermal convection in their subjacent mafic volcanic - clastic sedimentary piles. They belong to a rift -related metallogenic spectrum that includes sediment-hosted and Cyprus-type base metal deposits, and may diller genetically from these mainly with respect to rate and degree of crustal extension. Modern analogues to these deposits are f ound in the submarine volcanogenic sinters of the Gulf of California rift system.The associated lithologies and tectonic selling of Besshi-type deposits clearly distinguish them from Kuroko-type ores. This difference also seems to be reflected in their lead isotopic character. For example, leads from Besshi-type deposits in the Sanbagawa belt of Japan and from the Blue Ridge belt of southeastern U.S.A. lie on extended anomalous lead lines and have lowslopes in 207Pb/204 Pb - 206Pb/ 204 Pbspace (Sato and Sasaki, 1980; Leriuray, 1982), wheras those from most Kurokotype mining districts exhibit only narrow isotopic ranges and lie near or on the orogene growth curve (e.g. , Franklin et a I., 1981). More over, where Besshi- and Kuroko-type deposits are found in the same orogene, the former often occur earlier in the tectonic cycle than the tatter (e.g., Japan, the Norwegian Caledonides, the southern Appalachians and south-central Finland).Besshi-type deposits are not confined to any particular part of the world, or to any geological epoch. Moreover, in many mineralized belts, Besshi-type deposits are the predominant volcanogenic ore type. On a world-wide scale, deposits of this type therefore constitute an important base metal resource."

Jan 1, 1984

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed. The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grad~, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the fmal cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure 1."

Jan 1, 2003

By S. Noh, T. K. Kim, B. O. Lee

Future nuclear reactor systems such as a sodium-cooled fast reactor are being designed under severe conditions in terms of operating temperature and irradiation fluence compared to current commercial reactors. For realization of such systems, it is necessary to develop an advanced structural material having both high strength and irradiation resistance at high temperatures. Oxide dispersion strengthened (ODS) steel is considered as one of the most promising structural material because of its excellent creep and irradiation resistance on the basis of uniformly distributed nano-oxide particles with a high density. Up to now, ODS steels have been intensively studied and developed to apply these materials to the in-core structural component of future nuclear systems. Several advanced ODS steels were designed and fabricated by a mechanical alloying, hot isostatic pressing and hot extrusion processes. This study focuses on the effects of heat treatment parameters during the fabrication process parameters on the microstructures of ODS steels for future nuclear system applications.

Jan 1, 2015

By D. Duff, R. A. Cameron, R. E. S. Whitehead

"Although CO2 content indicates the quantity of carbonate in altered basaltic rocks, it does not measure the intensity of carbonate alteration. CO/CaO molar ratios, which correlate with the relative proportions of individual carbonate species, measure the intensity of carbonatization. The Timmins gold area is characterized by pervasive carbonatization, with large parts of the area having CO2/Ca0 ratios greater than 1, representing C02 supersaturation relative to CaO. The mean CO/CaO in the Timmins area is0.67, compared to 0.13 in two unmineralized control areas. Regional arsenic abundance in the gold-bearing area averages 4 ppm, compared to about 0.35 ppm for the non-mineralized areas. The average K20 and Rb abundances are similar in both mineralized and non-mineralized areas (about 0.30% K20 and 7 ppm Rb). Although there appears to have been no wholesale addition of K20 or Rb to the mineralized area from external sources, these alkalies have been redistributed internally, resulting in patterns of local enrichments and depletions which are characteristic of the mineralized region.Local target anomalies associated with known mineralization consist of CO2/Ca0 > 1.5, As > 10 ppm and K2O > 0. 75%. Not all three values are required to be above these thresholds in order to identify local targets. Combinations such as C02/ Ca0 > 1.5 and As < 10 ppm, CO/CaO 1-1.5 and K20 > 0. 75 or K20 > 0. 75 and As > 10 ppm are equally indicative of proximity to gold occurrences. Gold-bearing veins and associated anomalies occur throughout the entire volcanic succession and are not restricted to any particular stratigraphic horizons. The levels and patterns of alteration and occurrences of gold appear to be structurally controlled."

Jan 1, 1982

By S. Surapunt, C. M. Nyamai, K. Itagaki

"The use of liquid copper as a medium for zinc extraction has been used in the Warner Process as a method of processing zinc-lead sulphide ore. The recovery of zinc metal is based on the reaction:ZnS(s) + 2Cu(l) = Zn(g) + Cu2S(l)In this method, thermodynamic and phase equilibria investigations of the Cu2S-FeS-ZnS and Cu2S-PbS-ZnS systems are of importance and form the basis for the liquid sulphide phase which appears as a product and is used as a solvent in the Warner Process. Phase relations in the Cu2S-FeS-ZnS and Cu2S-PbS-ZnS ternary systems were determined experimentally at 1473°K to provide a fundamental basis for the new zinc smelting process. The results show that the solid solubility of ZnS in the two systems is very small (2 wt% to 3 wt% ZnS in FeS, 4 wt% ZnS in Cu2S for the Cu2S-FeS-ZnS system; less than 0.5 wt% ZnS in both PbS and Cu2S for the Cu2S-PbS-ZnS system). The Raoultian Activity Coefficient of ZnS in the liquid mixtures and the vapour pressure of zinc over the matte in both systems is relatively large (?° = 7.7 – 15.8, Pzn(atm) = 0.088 – 1.026 for the Cu2S-FeS-ZnS system; ?° = 8.9 – 12.9, PZn(atm) = 0.075 – 0.214 for the Cu2S-PbS-ZnS system). On the FeS-ZnS join, the only phases detected are FeS and iron-rich sphalerite (Zn, Fe)S. The binary join mixture occurs at about 92 wt% FeS-8 wt% ZnS at 1473°K. Electron microprobe examination of the quenched samples indicate about 47 wt% to 48 wt% FeS in sphalerite and about 2 wt% to 3 wt% ZnS in the iron sulphide phase. On the Cu2S-ZnS join, microprobe analysis reveals that the maximum solubility is 4 wt% Zn in liquid Cu2S and 3.6 wt% Cu in solid ZnS. In the Cu2S-PbS-ZnS ternary system, microprobe analysis of the quenched samples indicate on average, 5 wt% ZnS in the liquid phase region. The only phases detected on the PbS- ZnS join are ZnS and PbS. The eutectic phase contains, on average, 13 wt% ZnS. The phase relationships, very low solid solubilities of zinc sulphide in the liquid mixtures of both Cu2S-FeS-ZnS and Cu2S-PbS-ZnS systems, coupled with the high Raoultian Activity Coefficient of ZnS as well as the high vapour pressure of zinc over matte all favour the partitioning of zinc metal into the vapour phase. This new process is cost effective and bypassesthe expensive and tedious conventionaltechnique of zinc production involving oxidationof the sulphide ore by roasting followed bya reduction process to extract the zinc. Theresults indicate that a new zinc smelting technologyusing the Warner Process would bemore efficient and preferable over the traditionalmethods of zinc extraction."

Jan 1, 2002

By Knud Sinding

Environmental reporting by mining firms takes many forms and change frequently. The objective of these reports is related to increasing the legitimacy of mining firms with their diverse stakeholders. This study, focusing on internet-based reports, shows that there are considerable variations in reporting. This phenomenon is interesting because it belies the efforts pursued by leading industry members under iniatives such as the Global Mining Initiative and the Mining, Minerals and Sustainable Development project. The observed variation, both internally among reports and between reports and other industry policy statements, suggests that the industry needs to explore the possibilities for more convergence in terms of reporting quality. Based on theoretical constructs from the management literature we present a series of arguments defining necessary and sufficient conditions for durable and well-institutionalized reporting practices and standards.

May 1, 2002

By G. M. Dunn

Pressure leach autoclave circuits are employed in the leaching of ores, concentrates, mattes, alloys and intermediates for the recovery of metals into solution. Once the metals are extracted into solution the value metals can be recovered by hydrometallurgical means such as by purification followed by electrowinning, hydrogen reduction, pyrohydrolysis, crystallisation and other unit operations. In many of these integrated flowsheets the pressure leach step is pivotal to the recovery of the value metals from the host material. In an expansion or a new project, a large component of the capital cost can be associated with the pressure leach step and process engineers frequently look for opportunities to mitigate costs. This paper examines a new route for increasing the capacity of an exothermic pressure oxidation leach for sulphide concentrates, sulphide and phosphide mattes and alloys.

Jan 1, 2004

By H. C. Horwood

INTRODUCTION THE Argosy Gold Mines, Limited, which joined the ranks of active Ontario gold producers during the summer of 1936, holds a group of 21 claims on Casummit lake, in the Patricia portion, district of Kenora, northwestern Ontario. The Company is developing and mining goldbearing quartz veins that occur in a series of greywackes and slates of probable Keewatin age. The writer made a geological examination of the property and the surrounding area for the Ontario Department of Mines during the early part of the field season of 1936. This paper is a report on the general geology, structure, and ore deposits at the mine and is based almost entirely on data compiled during the examination. HISTORY Mineralization was first discovered on the property in May, 1929, by A. F. Hewitt, who, with J. A. Borthwick, decided that the country had prospecting possibilities and commenced work in April. Mr. Hewitt staked, and with his partner, J. Ziyone, still holds the group of claims lying immediately east of the present Argosy holdings. Mr. Borthwick staked six claims, K.R.L. 9,681 to 9,686, inclusive, adjoining Hewitt&apos;s on the west and later added claims K.R.L. 9,733 to 9,740, inclusive, to his holdings. F. Fiskness, who was also prospecting in the region, discoveted No. 1 vein on Borthwick&apos;s claims, and with his two partners, L. Parth and H. Jones, staked claims K.R.L. 9,758 to 9,763, inclusive, to the northwest of Borthwick&apos;s and Hewitt&apos;s ground. In July, 1929, the Casey Mountain Operating Syndicate, which held ground to the northwest, secured an option on Borthwick&apos;s claims. The Fiskness-Parth-Jones property was added in January, 1930, to protect the west dip of the veins. During the winter of 1930-31, the veins were explored by diamond drilling, No. 2 for a length ?of 900 feet and a vertical depth of from 51 to. 375 feet? and No. 3 .t~ a slope depth of 175 feet. I~ August, 1.931, after the msrallat10n of a miming plant, the Casey Summit Gold Mmes, limited, was incorporated to take over the property from the Syndicate. The Maple leaf Mines optioned a controlling interest in the stock in August, 1933, and on September 17th, 1934, brought a 50-ton amalgamation mill into production. From early in October to December 27th, 1934, when the mill was closed down, 4,094 tons of ore were treated to yield 887.89 ounces of gold and 87 .26 ounces of silver( ! ).

Jan 1, 1937

By A. G. B. Hayes, C. L. Renzoni

"AbstractThis paper provides a rough outline of economic expectations for the near future and then goes on to discuss their effect on the expected demand for metals, using zinc, copper, nickel and aluminum as detailed examples.IntroductionMINING, as you are all painfully aware, is a cyclical business. We believe that it will remain so as long as there are economic cycles.The fortunes of the industry are tied to those sectors of the economy where decisions can be postponed until more favourable times: automobiles, housing, appliances, inventory building and capital spending. Over the past two years, while U.S. GNP fell by 3.8%, automobile production declined by 31 %, from 9.7 million units in 1973 to 6.7 million in 1975. Housing starts plummeted some 43% from 2.1 million units in 1973 to 1.2 million in 1975. Little wonder that U.S. copper consumption fell by 37% and zinc consumption by 38% over the same period.With the rest of the world's economies moving in unison with that of the United States, it is also not surprising that times have been tough for mining.Arthur Burns, chairman of the U.S. Federal Reserve, contends that each recession sows the seeds of its own recovery. The worse the recession, the better the subsequent recovery. If this is true, then the lot of the mining industry should improve significantly over the next two to three years."

Jan 1, 1977

By Frank D. Adams

The Island of Ceylon, which is one of the most beautiful possessions of the British Empire, has been an abode of man from the very earliest times. The Veddhas, a wild tribe of some 4500 people still living in the fastnesses of the jungle in east central portion of the island, are believed to represent a remnant of the oldest inhabitants of which we have any actual knowledge, but in the caves in which they live there are found the stone axes and other implements of Palaeolithic people who represent the first race of men who inhabited our globe, and of whom they may be, for all that is known, the direct descendants. About the fifth century before Christ there came the Aryan invaders, apparently from the north of India, who drove the Veddhas into the remote fastnesses of the jungle and developed the remarkable Singhalese civilization whose high character is demonstrated by the remarkable and very extensive system of irrigation works which they built up, and through which they made the island wonderfully productive. Great cities arose, some of which are believed to have had a population of over a million souls and whose temples and public buildings show that the people were accomplished architects and sculptors.

Jan 1, 1926

By T. Koulomzine, R P. Jaeggin

The claims now held by Mount Wright Iron Mines Co. Limited were acquired by staking in 1956, 1957 and 1958, i.e., some time after the major deposits of the Quebec Cartier Mining and Normanvi!le Mining Co. (formerly Quebec Cobalt & Exploration Ltd.) were already discovered and partly outlined. The choice of the location of the Mount Wright hold-ings was governed simply by the -availability of ground still open to staking and by its proximity to properties held by major iron companies. Mount Wright Iron Mines had no previous knowledge of the geology and no aeromagnetic results were available to it to guide the choice of areas to be staked. In order to explore the newly ac-quired claims it was decided to make a grid of widely spaced magnetic profiles on the ground rather than use aeromagnetics. This afforded the possibility of making some geological observations simultaneously with the geophysical measurements.

Jan 1, 1961

By Karl J. C. Harries

"11.1. INTRODUCTIONA royalty is the most common form of interest retained by an owner who is disposing of his property or by a joint venturer who ceases, voluntarily or otherwise, to participate in the joint venture.1 Rarely does a non-participating party have a direct interest in the property and/or assets of a project, except during the period when a non-participating joint venturer may be having his interest diluted.2 In fact, it is most unwise to permit a non-participating party to have such an interest. It may give rise to significant problems that could prevent or substantially delay the development of an orebody and require a considerable amount of time, effort, and money to correct.3In negotiating a royalty, it is important to be aware that there is no law or convention that says, “You just don’t do that in a royalty agreement.” As with any agreement, inventiveness and flexibility on the part of the negotiator are not just assets, but virtual necessities. It is also for this reason that it is essential to read the royalty provisions, particularly the definitions, fully and carefully, especially if you are the recipient. On the other hand, if your inventiveness and flexibility cause your accountant to question the advisability of one of your ideas, pay close attention to him.4 He will, no doubt, have had experience with many royalties, and no competent professional adviser disparages a client’s ideas without good reason. Besides, he will probably be the person who will be determining the royalty or certifying the determination of it. At the very least, he will be auditing your general financial statements, which must, of course, reflect the royalty determination. Heeding his advice not only may make the determination easier but also will probably save you money in professional fees later on. Nevertheless, do not simply accept his comments or recommendations without understanding what they mean, why they have been made with respect to your royalty agreement (sometimes professionals have comments that they make as a matter of course and, even though they may be valid, you should require them to be justified to you), and how they will affect your royalty determination.It is surprising how many corporate payors insist that their standard royalty provisions5 be used as a matter of policy, thereby effectively tying the negotiator’s hands. It is even more surprising, and to professional advisers frightening, how many of the senior employees who insist that such a policy be adhered to, virtually without variation, do not know what is in the standard provisions and would be hard-pressed to explain them to a property owner. If standard provisions are appropriate, by all means use them, but do allow experienced and sensible negotiators some flexibility and make sure that everyone within the corporation who may have to use such provisions – negotiator and supervisor alike – knows what they contain and why they are as they are. For example, there are often good and convincing reasons to describe a deduction in a certain way or to include a certain specific type of deduction. On the other hand, quite often the answer to the question “why?” is that “it has always been there”; this is, or should be, an unacceptable answer. In any event, if you, as the negotiator, appear to know what you are talking about, are familiar and comfortable with your royalty provisions, and are backed up by your boss with the same words or reasoning, a property owner cannot help but be satisfied that you are knowledgeable, even if he still does not agree with your provisions. Finally, if you do use standard provisions, make sure that they are reviewed and updated regularly."

Jan 1, 2003

By C. R. Edwards

"Equity Silver Mines Limited, Canada&apos;s largest silver mine, has designed, built and operated a leach plant to reduce the levels of antimony and arsenic in its silver-gold-copper flotation concentrate. The orebody contained deleterious antimony and arsenic minerals in such proportions that the economic long-term sales contracts necessary to obtain project financing could not be procured. Construction of the leach plant therefore allowed development of the mine to proceed. Although the plant took some time to reach design throughput and product specifications, due to the complex and unique nature of the operation, these goals were successfully met and surpassed. This paper describes the physical plant and/or process technology modifications made to mold the main processes-concentrate leaching and filtering, autoclaving and filtration of by-products, and crystallization of salt cake-into an effective, economic operation.IntroductionEquity Silver Mines Limited, a member of the Placer Development Group, owns and operates an open-pit silver mine and related facilities located 37 kilometres southeast of Houston in north-central British Columbia. The mine occupies a 44 I-hectare (1089 acre) site at an elevation of 1300 metres (4265 feet) on the Nechako Plateau. Producing a copper concentrate containing high values of silver and gold, it is the largest silver mine in Canada and one of the largest in the western world. Equity stresses open communications, positive motivation, and production with safety, and achieved the best mine safety record in western Canada in 1984."

Jan 1, 1985

By Gustavo Angeloci

Artisanal mining is a rudimentary activity that today attracts over 30 million people in virtually all developing countries around the world. As the price of gold has steadily increased over the past decade, 15 million people have become involved in extracting this metal in 55 countries. Individuals have switched to mining from primary industrial sectors such as agriculture to increase their income. These workers generally have little capital, low education levels, and no previous experience in mining. Together with a lack of technical support from governments, these factors lead to disorganized and informal mining activities that generate environmental and social chaos. The absence of technical knowledge and capital has caused a proliferation of Gold Ore Processing Centres (GOPCs) around the world established by local entrepreneurs, who provide a way for miners to process their ores using amalgamation for a fee that is relatively low to non-existent. Gold recovery by the independent miners rarely exceeds 30 % and gold-rich tailings are left at GOPC facilities as a form of payment. GOPCs recover around 90 % of the remaining gold using cyanidation, flotation, and amalgamation, without any compensation paid to the miners. In processing these mercury (Hg)-contaminated tailings, Hg cyanide complexes are produced that are dumped into aquatic environments, leading to rapid bioaccumulation of Hg by fish. In the town of Portovelo, Ecuador, the establishment of partnerships between GOPC entrepreneurs and artisanal miners has proven to be successful in forming legal small-mining companies to create more equity and reduce pollution. About 108 GOPCs operate in Portovelo-Zaruma, with 40 % of these still working illegally without proper regulation and permitting. Over 20 % of these GOPCs continue to use grinding, concentrating and amalgamating of the gold, with 58 % performing cyanidation of tailings and/or gravity concentrates, and 15 % combining flotation with cyanidation. About 94 % of the GOPCs concentrate the ore prior to applying amalgamation, which significantly reduces Hg emissions to the environment. Incorporating flotation has given the operators increased skills in mineral recovery, with the side benefit of producing a copper concentrate as added value. Despite these innovations, mineral recovery is still inefficient, and waste management is a major challenge in creating true sustainability in this sector (technical efficiency together with social and environmental responsibilities). Further organization, training and capacity-building are needed. The principles of Lean Manufacturing Methods ("Just in Time" production and "Automation") are suggested as possible techniques to assist small GOPCs to become sustainable. In this concept, a larger mining company can become associated with artisanal miners in a partnership to provide training and investment for exploitation of small deposits that would be infeasible as a single large operation. As well, an International Training Centre for Artisanal Miners (ITCAM) is being established in Portovelo with collaboration of the Government of Ecuador to further enhance and upgrade mining activities in this region. ITCAM will provide artisanal miners with technical, business and environmental training to become responsible small-scale miners. In building this new capacity, ITCAM intends to create an atmosphere of trust to attract private and corporate investors to become partners with artisanal miners.

Aug 1, 2013

By R Thomson

The use of uranium metal in non-ferrous metallurgical practice is dis-cussed with reference to its alloying behaviour and chemical activity. It is suggested that the more promising applications are in the treatment of molten metals to combine with impurities. Mines Branch work along these lines is described for copper, zinc, magnesium, aluminum and nickel alloys. It is shown that a cop-per-uranium master alloy (25 per cent U) successfully deoxidizes molten copper without detriment to the electrical or mechanical properties of the product at residual uranium levels of up to 0.8 wt. per cent. Additions of uranium to alpha brass in amounts greater than the lead impurity content were found to remove the deleterious effect of lead on hot-workability. Similar deoxidizing and malleableizing effects were found with uranium additions to nickel. It is thought that uranium forms stable intermetallic compounds with many impurity elements. A significant malleableizing effect can therefore be expected in the presence of other elements besides lead.

Jan 1, 1963

By V. Gaudreault

Rio Tinto Alcan (RTA) has three smelters that use the Alcoa P155 technology: two in Canada (Grande-Baie and Laterrière, Saguenay, QC) and one in the United States (Sebree, Kentucky). The oldest RTA P155 smelter was built in the 1970s (Sebree) and had an initial current intensity of 155 kA. In the 1990s, RTA installed an amperage booster in Grande-Baie smelter to increase cell productivity. Since then, RTA has continuously pushed the limit of this technology and the target amperage that was 195 kA in 2005 has been increased to 210 kA in 2010.This article describes the successful plant-scale trials to increase current intensity from 195 kA to 210 kA, and the key performance indicator results. It demonstrates RTA&apos;s technology leadership to undertake such a development with its Brownfield smelters.

Jan 1, 2011