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By D. Kong, A. Klyashtorin, L. McGilp, I. Wilson

This work reports on applying iron oxide coated sands media in an experimental permeable reactive barrier to remove uranium species from uranium containing water. A field experiment was conducted at the legacy Gunnar uranium mine & mill site that was abandoned in the 1960s with limited to no decommissioning. The flooded Gunnar mine pit presently contains about 3.2 million m3 of water contaminated by dissolved U (1.2 mg/l), Ra-226 (0.4 Bq/l), and minor concentrations of other contaminants (As, Se, etc.). The water is seeping over the pit rim into Lake Athabasca posing environmental and health concerns. Iron oxide coated sands can be used to immobilize uranium species through an adsorption process. Methods for preparation of hydrous ferric oxide sorbents and their supported forms onto silica sands are described. Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (pXRD) were used to characterize the physical-chemical properties of the sorbent. The monolayer uranium uptake capacity (Qm) was estimated through the Langmuir adsorption isotherm. Adsorption kinetic experiments were performed in a lab environment before moving to a field trial. Based on these lab results and the input on field-scale appropriate geometries, a pilot permeable reactive barrier was fabricated and a field test conducted near the Gunnar pit in June 2019. This pilot test provided technical data and information needed for designing a full-scale permeable barrier based on the iron oxide coated sands, which may be applied for in-situ water treatment at Gunnar and other legacy uranium sites.

Jan 1, 2020

By Trang T. Tran-Valade

With continually increasing energy prices, the mining industry has been on the search for new energy optimization technologies. One area that is garnering great interest is Ventilation-On-Demand (VOD). Prior to selection and implementation of a VOD solution, it is important to fully understand the mine requirements as well as its existing infrastructure and the interaction with other automation in place at the site. With this information, a business case can be generated including a cost versus benefit comparison for various control strategies. To assist in the development of the business case, this paper will identify key areas for consideration and recommendations for an implementation plan.

May 1, 2013

By R. H. Duval

"In May 1936, Pamour started producing gold by cyanidation of flotation concentrates, and in 1939 was milling about 1, 600 tons per day.Refining records dating from 1939 show two oil-fired furnaces in use, (Rockwell type 46 11 x 29 11 inside oval shell).Refining time averaged 7. 83 hours during the year 1939, indicating a complete refining shift of about 9. 33 hours. That year appears to be characteristic of the period with regard to time required and results obtained.For that year total fineness (gold + silver) of the bars averaged 940 (approx.), but it frequently dropped below this figure, sometimes far below.Furnace lining life varied widely from three to seven or more months. Sillimanite was the standard lining but Mullfrax 41 was frequently used.For many years refining practice remained practically unchanged, and in 1960 procedure still consisted essentially of mixing a flux(% Composition Borax 41, Silica 11, Soda-Ash 11, Nitre 15, Mn02 22) with cyanidation precipitate in the ratio of l. 2 to l and heating to a medium heat (yellowishred, 2000° F) with a low flame for a long time. Time required was about 10. 5 hours per refining. Results were still much as detailed above.At this time it was decided to revise refining procedure, in an effort to shorten refining time and obtain consistently good bullion fineness."

Jan 1, 1965

By Y. Wang, J. D. Miller, C. L. Lin, Virginia Tech

Conventional flotation machines are typically limited to a particle topsize of 150-200 microns due to inherent constraints created by the pulp and froth phases. To overcome these limitations, a novel fluidized-bed flotation system called the HydroFloatTM Separator has been developed specifically for the purpose of floating coarse particles containing only small amounts of exposed hydrophobic minerals. Over the last decade, this technology has been successfully applied to industrial minerals with several full-scale units installed to recover particles up to and exceeding 3,000 microns diameter. More recently, sulfidebased test work has shown that this novel device is also capable of recovering metalliferous values at a grind size that is much coarser than currently used in industrial concentrators. In the current study, high resolution X-ray microtomography (HRXMT) was used to experimentally compare the degree of exposed grain surface area necessary to recover coarse particles using the HydroFloatTM technology to that attainable using a traditional mechanical flotation cell. The data indicate that exposed grain surface area is a critical factor for coarse particle flotation. For the gold-bearing sulfide ore examined in this study, the HRXMT data suggest that near complete recoveries of coarse (850x500 µm) multiphase particles containing as little as 1% exposed grain surface area were realistically attainable using the HydroFloatTM technology. As such, this new technology may offer a unique opportunity for increasing concentrator capacity by increasing the primary grind size needed for rougher/scavenger separations.

Jan 1, 2016

By Tao Long

Recently, the great amount of funds has been invested in the reconstruction of damaged infrastructure and house of subsidence area of coal mine and mine reclamation. This is a benevolent and popular work, which is highly praised. However, because of complicated collapse area problems in China, especially the less integrated control research in the collapse area of metal mine, and the technological weakness, how to effectively control the subsidence area, restore landscape and ecological environment, and utilize the abandoned mine land, are major issue related to the mining area of sustainable development. The research situation about the formation of metal mine collapse area at home and abroad is reviewed, and then the effect of the collapse area on the mine safety and ecological environment, the existing technical problems and development direction are analyzed. Lastly, the technical measures of the collapse area control and cooperative underground mining is put forward.

Oct 1, 2010

By Yulin Zhou, WenFeng Li, Wen Chen

"In this article, with the help of the X-ray photoelectron Spectroscopy (XPS), a modern test method, all the characteristics of the chlorite,and adsorption collector A6 on the surface of chlorite have been studied. There exist abundant carboxylic C-O and C=O structures in the Carbon XPS atlas with strong adhesive ability after the reaction between new collector A6 and chlorite, which indicates that the ring structure and ether-base functional groups can strengthen the reaction between collector A6 molecule and chlorite surface. The results of XPS analysis indicate that the photoelectron spectroscopy peaks of Mg2p and Al2p moved towards low energy after collector A6 absorbed on chlorite surface, which indicates that chemical bonding through electron cloud transfer happened between collector A6 and Mg, Al ions of chlorite surface. The chemical reaction promoted the adsorption of A6 on chlorite surface and eventually improved the ability of A6 to float and collect chlorite.INTRODUCTIONThere are a large amount of iron-bearing silicate minerals such as chlorite in different types of gangue minerals in iron ore from different areas besides quartz (Yingyong et al, 2012; Qiang et al, 2009). There always exist Mg2+, Al3+ Fe3+ and other metallic ions due the isomorphic replacement among the irons of this kind of minerals. The dissolution often occurs on the surface of minerals with abundant metallic ions during grinding process, and some ions are exposed on the surface, such as Mg2+, Fe3+, Al3+, Si4+, which can increase the surface electrical behaviour of iron-bearing silicate minerals (Wanzhong & Chuanyao, 2002; Yuping et al., 2007), making it easy for the surface to react preferentially with the depressants such as causticizing starch which making it impossible for the surface to reach with conventional anionic fatty acid collector (Mowla et al, 2008). Thus, the beneficiation efficiency is dramatically decreased and the improvement of concentrate grade becomes very difficult. The conventional aliphatic acid collector has some defects such as poor selectivity, poor low temperature resistance, sensitive to water hardness, etc. Thus, the addition of synergist (Liu, & Yu, 2015) or other compound reagents (Zhou et al, 2015) can promote the adsorption of reagents to mineral surface, and improve the collecting capacity and selectivity of aliphatic acid collector to minerals. The addition of polar group to nonpolar group in aliphatic acid can improve the water solubility, dispensability and hard water resistance (Tian et al, 2013). The nitrogen atoms in amid ate aliphatic acid collector can adsorb on mineral surface by itself and supply coordinate electron which can form chelating keys to improve the collecting capacity of collector. There exist coordinate electron in oxygen atoms of ether acid collector, which, along with the oxygen on carboxyl compose chelate with metal (Luo et al, 2015). There are also exist some opinions that the ether acid can arrange into similar crown ether structure which can absorb on mineral surface. A new alicyclic unsaturated ether acid compounds collector A6 is adopted in this paper, the structural formula is listed in Figure 1. The A6 has a strong collecting ability to chlorite with strong water solubility and low temperature resistance."

Jan 1, 2016

By Jochen Petersen, Caroline Muzawazi

The technical feasibility of ammonia leaching of PGM bearing Platreef flotation concentrates was investigated as an alternative method for the recovery of base metals prior to precious metal recovery. The composition of the concentrates includes 2.02% Cu and 3.17% Ni, and the major base metal minerals are chalcopyrite and pentlandite. Optimal leaching conditions were initially established in shake flask experiments to be a solution containing 4 M NH4OH, 4 M (NH4)2CO3 and a pH range between 9 and 10. These were used as base case conditions in column and batch stirred tank reactor tests, where the effects of total ammonia concentration and operating temperature were explored further. At optimal conditions nearly 100% Cu and Ni extraction were obtained in the batch stirred tank reactor, and 95% Cu and 60% Ni extraction was obtained in columns. The activation energy for chalcopyrite and pentlandite was 36 kJ/mol and 16 kJ/mol, respectively, in both reactors, indicating different reaction pathways for the two minerals. Gas-liquid mass transfer appears to be the limiting reaction step in columns much more than in tanks, and the degree of ammonia loss to air is significant. This initial test work indicates the feasibility of using ammonia leaching for this and similar materials as an alternative route to conventional smelting and refining prior to PGM recovery, but a number of technical challenges still need to be overcome.

Jan 1, 2014

By J. S. Phipps, D. R. Skuse

"Aqueous slurries of fine particle size calcium carbonate are used in a diverse range of end-use products. In many cases, the end-use performance is governed by the fineness of the particle size distribution. In turn, the maximum fineness of the particle size distribution is primarily determined by the efficiency of the dispersants used during the production process. Here, we report the sodium polyacrylate mediated dispersion of calcite and kaolin. Firstly, we report a colloid chemical description of the dispersant behaviour and attribute the stabilization to both steric and electrostatic mechanisms. Secondly, we describe how the understanding developed in the first part of the study can be utilized to produce more effective dispersant systems which allow the preparation of added value, higher solids and finer particle size calcium carbonate slurry products. IntroductionConcentrated aqueous dispersions of fine particulate kaolin and calcium carbonate are used extensively in the coating of paper. Currently, more than 10 Mt of such dispersions are used annually in North America and Europe alone, and worldwide consumption is growing at around 3% per year.Generally, paper is coated to enhance its visual appearance. Firstly, coatings improve the optical properties of the blank sheet, i.e., its brightness (or whiteness), opacity and gloss. Secondly, they improve the physical properties of the sheet that will influence the quality of the final printed image, such as surface smoothness, porosity, and ink absorption. In order to achieve these aims economically, paper coatings must be applied at high speeds and with minimal drying costs.Kaolin and calcium carbonate pigments are the major components of most paper coating formulations. Particle size distributions are chosen to maximize the optical benefits that they confer, and to allow the production of formulations that can be easily pumped, handled and coated. Coating pigments are generally produced and transported as slurries, and so it is important to obtain dispersions with the highest possible solids content, both to minimize drying costs and the quantity of water transported. This paper examines the dispersant technology that is currently used in the industry and the mechanisms by which it functions, and illustrates ways in which this technology has developed and could be further improved in the future."

Jan 1, 2003

By R. J. Enkin

Modern mineral exploration depends on multidisciplinary 3-dimensional integration of geological and geophysical data. Identification of the geological sources of geophysical anomalies requires knowledge of the physical properties fingerprint of rock types, formations and their alteration products. Understanding how and why rock physical properties vary within the Earth's subsurface ensures that appropriate geophysical exploration methods can be chosen, and allows for more efficient and effective surveys to be designed. Physical properties knowledge is integral to geophysical modeling - measured data or values estimated based on geological understanding are used to produce realistic forward calculations and to constrain inversion models. Mira Geoscience and the Geological Survey of Canada, in collaboration with industry and academia, are building a Rock Properties Database System (rpds.mirageoscience.com). It compiles the most valuable physical properties for mineral exploration (density, porosity, magnetic susceptibility and remanence, electrical resistivity and chargeability) linked with location and lithological metadata. A critical knowledge gap, addressed in this study, concerns the dependence of physical properties on alteration and mineralization processes. We report on the results of a collaborative University of British Columbia - Geoscience British Columbia project, ?Integrated Geological & Geophysical Porphyry Models: Adding Value to Geoscience BC Geophysical Data?. As part of the QUEST and QUEST-West geophysical initiatives, Geoscience BC focused detailed geophysical surveys on a suite of six known porphyry deposits: Mount Milligan, Endako, Huckleberry, Bell, Granisle, and Morrison. Physical properties for a set of 269 samples of characteristic host rocks and their altered equivalents were measured. The causes of physical properties variations were investigated through their correlations with ore and alteration mineralogy determined from thin-section observations and X-ray diffraction analyses. Physical properties of variably altered host-rocks and intrusive rocks vary significantly between different BC porphyry deposits. No specific unifying geophysical model exists that can be uniformly applied during exploration. Knowledge of local background geology and local physical properties variations is necessary as host-rocks and intrusive rock compositions vary depending on magmatic affinities, and alteration styles will vary reflecting host-rock compositions, crustal depth and influence of meteoric water. A district-scale exploration strategy requires location of intrusive bodies, which are commonly magnetic, resistive and low in density. Correlations should not be expected between density and magnetic susceptibility, because alteration may lead to magnetite destruction or to secondary magnetite development. Deposit-scale ground geophysics might image potassic alteration zones that can be magnetic in both alkalic and calcalkalic systems. Low magnetic susceptibilities, resistivities and densities might aid in locating the typically more porous phyllic and argillic zones. All geophysical data must be interpreted with background knowledge of local rock types and in light of the expected deposit model and associated magmatic and hydrothermal processes. The most effective means to building physical properties knowledge prior to geophysical investigation remains collecting rock physical properties measurements. The cost of rock properties data collection is low, relative to the overall costs of running a mineral exploration program, and can provide an important framework for design of geophysical surveys, survey method selection, geophysical modelling, and data interpretation.

Aug 1, 2013

By M. Rafieazad, P. Fathi, X. Duan, M. Mohammadi, A. M. Nasiri

"Direct metal laser sintering (DMLS) is a metal additive manufacturing technology that creates highly complex components by fusing metal powder into a solid part. In this study, the impact of surface roughness on corrosion resistivity of AlSi10Mg_200C alloy manufactured through DMLS was investigated. The as-printed DMLS-AlSi10Mg _200C alloy was subjected to various surface finishing processes including grinding and sandblasting. The corrosion performance of the surfaces was then evaluated using potentiodynamic polarization testing and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution to mimic seawater environment. Surface characterization and corrosion morphology of the samples were assessed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy. The results of this study show that the surface finishing process and the resultant surface roughness has a significant impact on the corrosion resistivity of the DMLS-AlSi10Mg_200C alloy in the seawater environment.INTRODUCTION Direct Metal Laser Sintering (DMLS), also known as Selective Laser Melting (SLM) (Sames, List, Pannala, Dehoff, & Babu, 2016), Laser Beam Melting (LBM), or Laser Metal Fusion (LMF) (Herzog, Seyda, Wycisk, & Emmelmann, 2016), is an additive manufacturing process that utilizes a precise, high-power laser to micro-join powdered metals and alloys layer by layer to form almost fully dense and functional components in three dimensions from the 3D computer-aided design (CAD) data. Complex geometries not possible with conventional manufacturing processes can be readily manufactured with high accuracy using the DMLS process with no need to time-consuming tooling."

Jan 1, 2018

By J. W. Craig

THERE are, broadly speaking, three classes of refractories: acid, basic, and neutral. Fireclay, diaspore, silica, and the sillimanite group of minerals are included in the acid class, which for the most part are not very resistant to basic slags. The neutra! class includes chrome, graphite, and silicon carbide, while most important in the basic class are magnesite and dolomite. Although chrome is a neutral refractory, it has no sharp distinction from magnesitic refractoriness. The two are mineralogically (1) and chemically related, and there is available on the market a complete range of brick from straight chrome to straight magnesite. In many indus trial applications, one. type may be replaced by another. The present paper is confined entirely to such refractories. The following types of basic and neutra! brick, each sold under sorne special trade name, are available for use in Canada: (1) Burned chrome from crude ores (2) Burned chrome from treated ores (3) Chemically bonded (unburned) chrome-magnesite ( 4) Burned chrome-magnesite (5) Chemically bonded ( unburned) magnesite-chrome (6) Chemically bonded (unburned) high-iron magnesite (7) Burned high-iron magnesite (Regular) (8) Burned low-iron magnesite (9) Burned olivine-magnesite (10) Burned magnesitic dolomite-chrome (Magnecon) (11) Chemically bonded magnesitic dolomite-chrome (Magmecom) (12) Dolomitic brick

Jan 1, 1936

By Ahmad Ghahreman, Denver Cowan, Yeonuk Choi

"Testwork was conducted in order to compare the effectiveness of carbon based catalysts while oxidizing a gold-bearing pyrite concentrate under atmospheric conditions. Without the use of a catalyst the oxidation of pyrite was incomplete after 96 hours, resulting in roughly 60% pyrite oxidation. Furthermore the resulting sulphate yield from unassisted pyrite oxidation ranged between 72 and 84%. It is evident that atmospheric oxidation of pyrite is not viable due to slow oxidation kinetics and high sulphuric acid production when using a ferric sulphate media without a catalyst. The effect of two different carbon based catalysts, one Lewatit® AF 5 a new microporous carbonaceous bead, and the second a granular coconut shell based activated carbon, were tested under the same oxidation conditions as the unassisted pyrite tests. After 96 hours, Lewatit® AF 5 assisted oxidation showed approximately 96% pyrite oxidation with a sulphate yield ranging between 26 and 35%, while the activated carbon assisted oxidation reached approximately 100% pyrite oxidation with a sulphate yield between 36 and 37%. Testwork indicated that not only does the addition of a carbon based catalyst greatly improve the oxidation kinetics and lead to almost complete oxidation, the sulphate yield is also drastically reduced, resulting in very high elemental sulphur yields.INTRODUCTION Pyrite is an important sulphide mineral due to its ability to contain invisible gold concentrations up to 132 g/t (Chryssoulis & Cabri, 1990). As a result, ores composed of only a small amount of pyrite still have the ability to contain high gold grades. This refractory gold cannot be accessed via conventional gold leaching processes, such as cyanidation, and additional oxidative pre-treatment is required to liberate the gold, making it more amenable to extraction (Marsden & House, 2006). Current oxidative pre-treatments do exist consisting of both pyrometallurgical and hydrometallurgical processes including high temperature and high pressure leaching within autoclaves, biological atmospheric leaching and roasting. Autoclaves are a proven process reaching desirable recoveries within approximately a 1–2 hour retention time, due to the increased temperatures and pressures, allowing for an increase in dissolved oxygen (Marsden & House, 2006). The typical reaction for pyrite oxidation within autoclaves is presented in Equations 1, 2 and 3."

Jan 1, 2017

By Reno Pressacco

Abstract- Agrium Inc. is a world leader in the production, distribution, and marketing of agricultural products and services in both North America and Argentina. The new phosphate mine and mill complex located southwest of Kapuskasing, Ontario, was constructed to replace an offshore supply of phosphate rock, and produces a high-grade phosphate concentrate. The Cargill Township Carbonatite Complex is one of a series of carbonatite complexes in the region that are hosted by the 1.9 Ga aged Kapuskasing Structural Zone. The carbonatites in the mine area have intruded Archean gneissic granodiorite rocks of the Wawa Subprovince, and metasedimentary rocks of the Quetico Subprovince. The Cargill Carbonatite Complex displays a typical concentric zonation pattern from an outer ring of alkalic pyroxenites, through an inner ring of sövite-carbonatite, to a central core of rauhaugite-carbonatite. The initial carbonatite intrusion and subsequent residual orebody have been modified by faulting such that the northwestern third of the complex has been displaced approximately 2.5 km northeast. The phosphate ores are composed principally of residual apatite sands that were formed by the weathering and dissolution of the soluble minerals of the carbonatite protolith. These ores are subdivided by their iron content into high grade (A ores) and lower grade (B1 and B2) ores. They are separated from the primary unweathered carbonatite by a layer of saprolite, whose thickness varies depending upon the composition of the underlying carbonatite. Cretaceous waste materials consisting of well-sorted silica/kaolinite sand and peat deposits are typically found to stratigraphically overlie the ores. A minor amount of the ore feed comes from cemented phosphate ores. All rock types are covered by Pleistocene glacial tills and clays.

Jan 1, 2001

By Unknown

We are indebted to the Consolidated Mining and Smelting Company of Canada Limited for the several pictures in this issue showing the progress made in new construction at Tadanac and at Bonnington Falls, B.C. Plate No. 1 shows the down-stream side of the No. 1 hydro-electric station of the West Kootenay Power and Light Co. Limited at Bonnington Falls, on the Kootenay river, at which 17,500 k.v.a. will be developed to meet the requirements of the enlarged zinc and lead refineries at Tadanac. The generators, exciters and switch apparatus were supplied by the Canadian General Electric Company and the step-up transformers by the Canadian Westinghouse Company Limited. The plant throughout was designed, manufactured and erected by Canadians. Plate No. 2 shows the casting room of the new lead-plant and plate No. 3 the new tank-room of the electrolytic lead refinery at Tadanac. These additions will increase the capacity of the lead refinery by some 150 tons daily. The extensions also include practically doubling the zinc plant, and the gold and silver refineries. With the exception of the new stack, all designing construction and installation of the various plants is being done by the Company's own employees at Tadanac. Plate No. 4 shows the progress made in the construction of the new reinforced concrete stack at Tadanac. This stack, of 21 feet inside diameter at the top, will be brick lined and when completed will rise 400 feet above its foundations: the tallest of its kind in the world. The construction is in charge of the Rust Engineering Company of Pittsburgh, Pa. Plate No. 5 is a panorama of the Tadanac smelters and refineries. The photograph was taken from the roof of the lead smelter and gives an excellent idea of the size of the plant and its surroundings. Tadanac produces electrolytic lead, zinc and copper and fine gold and silver. During 1924 the company treated 1,333,523 tons of ore and produced: 161,400,- 769 pounds of lead; 92,197,824 pounds of zinc; l,382,750pounds of copper; 4,074,044 ounces of silver, and 26,976 ounces of gold.

Jan 1, 1925

By Corrie Pitzer

Safety performance in many companies and even industries has stalled in the few years. Accidents rates are at a ?plateau? and yet, serious accidents and fatality rates are not. In more dramatic cases, such as in the BP Texas disaster, organizations that have ?exemplary? safety statistics, suddenly have a catastrophic or multi-fatality event occurring. Other classic examples are the Piper Alpha disaster and NASA?s Challenger and Columbia disasters and even the Chernobyl nuclear reactor. Looking into the root causes of these accidents provides an insight into the events and deficiencies that led up to the accident, but what are the common features in the organization?s mindset? What characterizes these organizations? decision making, their approach to safety and to risk and are there specific cultural features that can be delineated? The research and review presented in this paper covers a period since 1994, which started in the Australian resource industry and since then covered international events. The features of these organizations are summarized as the seven deadly delusions, based on extensive research since 1997 of organizations that suffered unexpected disasters. Their huge focus on safety, the achievement of lofty goals and celebration of safety successes led to ?mindset? that they are leaders in safety, protected by an extraordinary safety system and that their safety incident figures indicated a truly world-class safety performance. It led them into the trap of the seven deadly delusions?

May 1, 2011

By Catherine N. Mulligan

Thickening of mine tailings is a relatively new concept for their sustainable management. Removal of water from the tailings to form a paste instead of slurry disposal decreases environmental and geotechnical concerns. As the use of these pastes is relatively new, their behaviour requires investigations such as liquefaction and seismic stability, freeze-thaw behaviour, consolidation and leachate characterization. Slurry density, ore type, particle size distribution, specific gravity and environmental conditions can all influence paste characteristics. In this paper, the effect of the above-mentioned parameters is examined. New developments in water removal, and additives (such as flocculating agents, cements, organics, fertilizers, etc) leading to low moisture content tailings are reviewed, and the potential for thickening to enable sustainable management of mine tailings is discussed with respect to storage volume requirement, use of virgin land, consolidation of the tailings, land use after decommissioning.

May 1, 2007

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 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 C. J. Newman, D. J. Kemp, R. M. Sweetin

"The smelter is described by area; feed preparation, continuous furnace line, gas handling and auxiliary systems, blister refining, Hazelett casting of thin anodes, and scrap remelting. Early smelter campaign data is presented and compared to design. Some modifications to the basic design of the furnaces and gas trains are indicated, with their respective impacts on improving smelter performance.Plant compactness, the use of jumbo tanks, and a highly automated electrode handling system are featured in the refinery description, with brief coverage of the liberator and slimes leaching sections. Early experience in refining thin regular Hazelett anodes, and submersible pump recovery of raw slimes are relayed, together with automatic stripping from titanium blanks.Refinery tonnages and operating parameters are given showing the relatively trouble-free attainment of refinery design performance.IntroductionPrevious papers and articles ( 1), (2) ,(3 ) have described the metallurgical facilities serving the copper-zinc-silver Kidd Creek orebody located near Timmins, Ontario. For convenience a brief review of their mid-1983 operating status is presented.The concentrator, originally designed for 9,000 short tons, was commissioned in late 1966. It can now comfortably process over 13,000 metric tonnes per day largely as a result of the addition of a fourth circuit in 1978."

Jan 1, 1984

"Many underground mines are achieving extended life and optimizing existing facilities by mining at greater depths. The challenges to do this require a sound engineering approach to mine design and mine services, as well as ingenuity in safety design. The social consequence is full utilization of existing infrastructure.Accessing ores at depths of 2000 m to 3000 m requires exceptional hoisting design. May’s theme issue includes a paper that examines a case study of one such hoisting plant, with emphasis on the hoist rope selection at Agnico-Eagle’s Penna shaft. The paper also describes the process whereby consultation with provincial safety authorities resulted in a revised safety factor suited to the hoist. Another paper examines the challenges of ventilating mechanized mines to 3000 m, including air cooling and dilution of diesel exhaust emissions. Vent system designs are discussed, using sound engineering design, and proven technology that minimizes emissions to achieve cost efficiencies. The paper suggests design based on process and ventilation simulators to obtain realistic economic data at the design stage. Increased ground pressures present unique challenges for production and safety. While this is not confined to deep mining, one paper examines rock pressures and seismic events at the Brunswick mine, for which experience may be applied at depth. It describes seismic monitoring as a predictive tool in a real mine situation, and how it is used to improve overall recoveries and maintain worker safety."

Jan 1, 2004