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By T. Nagasaka, T. Miki

Suppression of CO2 and waste such as slags discharged from iron- and steelmaking processes are some of the typical major issues for the protection of global environment and sustainable growth of steelmaking industry. Utilization of active phytoplankton growth will be one of the best options to stabilize and suppress carbon dioxide at high-efficiency. Inorganic minerals such as C, 0, N, Si, P and Fe are necessary for phytoplankton multiplication. It is crucial for supply of nutrition into seawater effectively for phytoplankton multiplication to understand the dissolution behavior of some elements from steelmaking slags into seawater. The morphology of the precipitated phases in steelmaking slags during cooling period was investigated in the present work. The dissolution behavior of some elements from steelmaking slags into artificial seawater has also been studied. The effect of nutrient dissolved into seawater on phytoplankton multiplication, some examples of marine structure made from steelmaking slag, and estimation of CO2 fixation amount by marine phytoplankton are also discussed.

Jan 1, 2004

Post--Crunch Financial Management -An Overview A. The Industry and the Capital Markets B. .The SME -De-risking the Current and New Assets Followed by: C. The Lender?s Perspective on Re-financing?Jeff Stufsky, BNPParibas, NYCD D. .The Agency/Export Credit Lender Perspective?Doug Macaulay, EDC, Ottawa E. The Foreign Political Insurance Perspective?Pierre Vieillescazes, Carrick-Bend, Washington, DC ?Four Fundamental Metal Models No Longer Prevail. ?Mining is in new ?waters?: so be prepared (next page). ?Capital markets are uncertain-so be your own financier first ?If tight capital may remain, prepare to triage based on cash-flow production (not oz, lbs, tonnes, etc) ?Know your banker/financier(and it should know mining) ?In the past, it was ?know your borrower? ?The climbing team can fall if one climber carries too much ?Constantly re-assess the risk matrix (and j/v?s), and ?De-risk/diversify both the asset and the capital base

May 1, 2010

By Ross Dimmock

The productivity of a mine has the same goals as the quest to complete a tunnel project both safely and within time. A key aspect to achieving this goal is to excavate and support the working face as quickly as possible, allowing early re-entry to start construction of the next advance in safety. As with tunnels, the use of high performance wet-mix sprayed concrete has increased in mines dramatically over the last few years, and year on year has seen a stepwise increase in shotcrete performance, particularly in the first few hours. Shotcrete early age strength development clearly offers mining teams enormous advantages by allowing early, safe re-entry to the face. This paper illustrates that in the hard rock tunnelling field, modern shotcrete approaches do not cause delays in re-entry, but allow a continuous construction cycle. Furthermore, the paper identifies the most suitable, up-to-date shotcrete admixture and equipment technology available to the mining community to permit early re-entry.

May 1, 2003

By I. Takahashi

Recently, electronic devices have become smaller for some kinds of electronic devices, thermal dissipation and electrical conductivity of conventional Fe based alloy becomes insufficient. We selected the Cu-Fe based alloy CDA19400 and optimized the wire manufacturing process. Precipitates during aging treatment were observed by TEM. The size and distribution of the precipitates varied according to solution treatment temperature. With solution treatment at 950°C, the precipitates of y-Fe as fine as 10 nm were distributed dense in the copper matrix with coherency. For the solution treatment at 750°C, y-Fe of approximately 200 nm was observed. Comparing heat resistance of drawn wires, the material at 950°C treatment was superior. Electrical conductivity decreased from 63% IACS upon aging to 29% IACS by drawing. It is considered as particular phenomena for wires where materials are drawn with high reduction ratio. By the optimized manufacturing process, we successfully developed a new wire that has superior in strength, thermal conductivity, electrical conductivity, heat resistance and repeated bendability.

Jan 1, 2007

By R. von Gal

Hazelett Strip-Casting Corporation has been producing the Hazelett® twin-belt casting machines for copper casting since the mid-1960s. The first commercial casters were developed for copper alloy strip and anode plate. In 1968, development work was started to adapt the twin-belt caster for copper bar casting to be rolled in-line into wire rod. Since then, 36 casters have been sold as part of the CONTIROD® system for the production of a substantial portion of the world's copper rod supply. A unique feature of the twin-belt caster is the mold's ability to comply with the size and shape of the cast bar as it shrinks during solidification. Maintaining contact between the mold and the bar provides a high rate of heat transfer as well as other benefits, including the prevention of surface imperfections caused by remelting in the mold. This paper will give an overview of the continuous evolution of the twin-belt caster technology with an emphasis on recent developments in compliant mold technology for copper casting.

Jan 1, 2007

By M. Boussuge

Ceramics and refractories have many common constituents and consecutively exhibit several analogous properties. For example, concerning the thermomechanical properties this paper will focus on, the type of creep that can be observed in both materials is often the same (kinematic hardening). Changes in microstructure (phase transformation, dehydration, sintering, crystallisation,...), induced by heating and/or cooling, can also drastically modify the mechanical behaviour of ceramics and refractories. But the coarse granulates, the porosity and the impurities contained in industrial refractories may lead to specific responses of this material to thermal and/or mechanical loadings. In particular, some differences can be observed with technical ceramics in the main type of damage observed in service : diffuse damage in refractories (microcracking) and localised damage in ceramics (macrocracking). In this paper, the possibilities of transferring a part of knowledge from ceramics to refractories will be discussed, in the field of thermomechanical properties : experimental characterization techniques, mechanical behaviour models. Finally, some problems caused by scale effects and by the integration of thermomechanical properties of refractories in the numerical simulation of industrial structures will be evoked.

Jan 1, 2004

In recent years, China and India have emerged as major players in the copper sector. Over the last decade, around 50% of additional global refined copper usage growth can be attributed to them. The paper provides an overview of the current and future copper supply and demand situation in both countries. Results from two market studies commissioned by the International Copper Study Group (ICSG) are complemented with recent copper statistics on North-East and South-East Asia, as well as further sectoral analysis. Developments and trends in copper mining and metal production, semis production, and major end use areas are highlighted. While providing insights into sectoral patterns and growth trends, the paper provides the basis for comparing structure and output of the copper sectors in some of the major copper-using countries in Asia. Afterwards, the current copper reservoir in use associated with infrastructure, buildings, industrial equipment, transportation systems and households is assessed using the ICSG Copper Flow Model. Finally, the identified copper flows are analyzed regarding the potential impact on the future world supply and demand situation.

Jan 1, 2007

By R. S. Forgan

The synthesis and study of a systematic series of phenolic oximes have shown that substitution in the 3-position can greatly affect extractive efficacy. Solid state, solution and gas phase analytical techniques, including X-ray crystallography, EPR and IR spectroscopy and collision induced dissociation mass spectrometry have been assessed for their applicability in interpreting the origins of differences in extractant strength. The dominant substituent effect on pH0.5 is the change in ligand pKa, with the more acidic ligands being stronger extractants. The influence of the 3-substituent on the stabilising intracomplex H-bonding of their copper(II) complexes also affects extractant strength. The 3-NO2 substituted ligand shows the lowest pH0.5 value, due to a combination of its low pKa and a stabilising bifurcated H-bond assembly around the copper(II) centre. Appending an aminomethyl group to the 3-position gives a ligand capable of binding a metal and its attendant anion. These metal salt reagents show potential to open up new flowsheets for the processing of high tenor copper feeds.

Jan 1, 2007

By K. Morikawa, K. Asano, J. Yoshitomi

The quality requirements for ladle shrouds have become stricter year by year to the pursuit of higher productivity and improved quality in the continuous casting of steel. The ladle shrouds must be sufficiently durable under severe conditions, such as operation without preheating and during several sequential castings. The consideration is that ceramic fibres, which have been applied in shrouds for thermal insulation during casting, could pose a risk to the worker's health. We realized materials for the ladle shrouds which show high strength and low elasticity. At the same time pursuing effective insulation, a coating which contains no fibres (Foaming Coat) has been developed, replacing the conventional one containing fibres. These materials are durable under conditions of repetitive use and consequently satisfy the customer's demands. The ladle shrouds which were improved in this way have achieved an excellent durable life in hot service of three times that of conventional ones. This paper reports the recent technological developments in ladle shrouds as well as their performance under hot operating conditions.

Jan 1, 2004

By P. V. Barr, Y. -H. Li, A. P. Watkinson

Subsequent to a campaign of pilot-kiln trials of firing bio-oil and natural gas, scale-up to commercial lime kilns was made using an in-house mathematical kiln model. Both dry limestone and lime mud kilns of 3.5 m OD. by 100 m length were used for bio¬oil firing simulations. Comparisons were made against natural gas firing on the basis of specific firing rate, off-gas volume, energy consumption and overall lime quality. Model simulation results indicate that conversion from natural gas to bio-oil with no productivity loss will increase energy comsumption by about 7.5% and total off-gas volume by about 8%. Alternatively, a 6% decrease in productivity would be expected if off-gas volume is maintained constant. The calculations are sensitive to deviations in the lower heating value (LHV) used in the simulations. A 5% increase in the LHV of the bio-oil, which could result from a 3% decrease in the moisture content, reduces the energy penalty to 2% coupled with a slight reduction in off-gas volume.

Jan 1, 2004

By Y. Masuda, Y. Nakamura, K. Haraguchi, A. Taniguchi, K. Arita

Availability of the elements originating from steelmaking slag for various marine phytoplankters including purely cultured strains and natural populations was tested in land and shipboard laboratories. The results obtained demonstrate that, although their solubility was not uniform among different slags, dissolved iron, silicate and phosphate from the slag stimulate phytoplankton growth. No negative effect of the slag addition on their growth was observed at lower dose, e.g. less than 200 mg/l. Since most coastal waters are the hypernitrogenous environment due to anthropogenic load of ammonium, the slag can be an ideal source of silicate and phosphate, which restore the hyper-nitrogenous condition into truly eutrophic condition with balanced Redfield ratio. In so-called HNLC (high-nitrate low-chlorophyll) oceanic areas such as the Southern Ocean and the subarctic North Pacific, where iron is almost only limiting factor of the phytoplankton growth, the slag could also be a source of iron and enhance CO2 fixation by phytoplankton photosynthesis. (Key words: carbon deposition in deep-sea, marine environmental remediation, phytoplankton, slag as a source of iron, phosphate and silicate.)

Jan 1, 2004

Despite the claims of energy efficiency and the considerable development that has gone into dramatically extending rolls’ life and facilitating rolls’ change-out, in the six years since the last SAG conference, only a few HPGR operations have entered the realm of mineral processing. Risk barriers to the take-up of new equipment or processes are: a massive increase in materials handling issues as well as in the number of pieces of equipment required, low total circuit potential energy savings, and similar or higher capital costs. An alternative route is to make use of the complementary strengths of the HPGR and SAG in hybrid circuits. Minimising materials handling issues, providing an ideal balanced feed to the AG or SAG mill, and improving controllability through shifting grinding load as the RoM feed changes, are all potential major advantages to this approach. Conceptual circuit layouts, based on real measured ore and equipment data, are presented here to illustrate the potential production upside, the reduction in operating costs and the reduction in the physical and energy footprints.

Jan 1, 2012

By N. Hiroyoshi

In the leaching of chalcopyrite with sulfuric acid solutions, the copper extraction rate reaches a maximum at a given redox potential. This article reviews our studies on the determination of the optimum redox potential for chalcopyrite leaching. Shaking flask and column leaching experiments for a chalcopyrite concentrate were performed under various conditions, and the results were analyzed using a normalized redox potential defined from a reaction model assuming the formation of an intermediate CU2S from chalcopyrite. Factors, such as metal ion concentrations, solid/liquid ratio, and presence of iron-oxidizing bacteria, caused significant variations in the copper extraction versus time plots. However the copper extraction rate versus normalized redox potential plots were independent of the above factors and the copper extraction rate reached a maximum at the normalized redox potentials around 0.43. Converting the normalized redox potential to the solution redox potential gives the optimum redox potential for chalcopyrite leaching as a function of cupric and ferrous ion concentrations. This semi-empirical equation can be used to predict the optimum redox potential during leaching operation, and is useful to design the redox-controlled heap leaching for chalcopyrite.

Jan 1, 2007

By Jean-François Doyon

Les aspects environnementaux des activités minières d?exploitation réalisées sur le territoire québécois sont encadrés par divers cadres légaux, réglementaires ou autres (directive, politique, guide) tant au niveau provincial que fédéral. Ces cadres s?appliquent à l?un ou l?autre des trois grandes étapes du projet, soit lors de l?étude d?avant projet, pendant l?exploitation ou à la cessation des activités d?exploitation. Comme la réglementation environnementale est de plus en plus nombreuse, ces dernières années, cette présentation vise à exposer les principaux cadres provinciaux et fédéraux actuellement en application au Québec pour le secteur minier et à en dégager les particularités. ABSTRACT The environmental aspects of mining activities carried out across Quebec fall within the scope of various legal, prescribed or other frameworks (directives, policies, guides) at provincial and federal levels. These frameworks apply to one or another of the three major steps of a project: preliminary design, mining and closure. As the number of environmental regulations has greatly increased during the past few years, the object of this presentation is to state the main provincial and federal frameworks currently applicable in Quebec for the mining sector and to identify their special features.

Nov 1, 2002

By Alan L. Sangster

Abstract -Auriferous, bedding-parallel veins occur in zones of carbonaceous, argillaceous and sulfidic turbidites in the Lower to Middle Cambrian sandy flysch of the Goldenville Formation. The ?34S values for vein and wall-rock arsenopyrite and pyrrhotite, and for regional pyrite and pyrrhotite, are highly positive. The values are similar to those from Cambro-Ordovician sediment-hosted deposits of other types, and display trends that increase upward in the stratigraphic sequence. The similarity in composition of vein and wallrock sulfides indicates a seawater-sulfate source for sulfur, derived from the enclosing rocks at the time of vein formation. The upward increase in ?34S values is consistent with closed system sulfate reduction in the anoxic portion of a stratified water-column. Published ?18C and ?18O values for Meguma Group vein carbonates are unlike those of other gold-vein carbonates, but are similar to those of diagenetic-metamorphic carbonates from the Meguma Group and elsewhere. These data indicate that the source for the vein-related sulfides and carbonates may be the host strata; possibly the arsenic and gold were derived from the same source.

Jan 1, 1992

By H. Kuboyama

The synergistic effects of polymer additives such as gelatin and polyethylene glycol) (PEG) and Cl- on Cu electrodeposition have been investigated by measuring the polarization curves for Cu deposition, by rotating ring-disk electrode technique and by AC impedance measurements. The cathode potential for Cu deposition was greatly polarized in solutions containing both Cl- and gelatin or PEG, showing evident synergistic effect of polymer additives and Cl- on Cu deposition. The cathode potential was shifted to the less noble direction with increasing the concentration of Cl- in solutions containing polymer additives and showed the maximum polarization at Cl- concentration range between 0.1 and 1 mmol/L. The rotating ring-disk electrode technique revealed that Cu deposition in solutions containing small amounts of Cl- proceeded with initial formation of adsorbed intermediate CuClad. The Cole-Cole plots obtained by AC impedance techniques suggest that the reduction of CuClad is suppressed by polymer additives. The morphology of Cu deposited from solutions containing both PEG and Cl- showed the compacted surface composed of smaller grains due to an increase in the overpotential for Cu deposition.

Jan 1, 2007

By Jacek Paraszczak

As the deposits located closer to the surface are getting depleted, more and more Canadian mines produce ore from considerable depths. Deep mining represents a number of serious challenges including high rock temperature. Conventional diesel powered loadhaul- dump machines and trucks so widely used in metal mines constitute an additional source of heat and noxious gases. Due to this, they have a substantial adverse impact on a quantity of fresh air required and a cost of ventilation, particularly since the mines have to meet more and more stringent regulations in this respect. In this context, the paper examines possible alternatives for diesel powered equipment, both these commercially available as those at the stages of prototypes or under development. They are reviewed with regards to their principles, required infrastructure, stage of technology development and its progress. The questions of their flexibility, practicality and economic viability are also addressed. Following the above a potential for their implementation and possible benefits (if any) in the conditions of deep Canadian mines is discussed. The paper concludes with short to medium term predictions concerning the most promising drive alternatives for vehicles destined to operate in deep metal mines.

Feb 1, 2008

By M. Schwarze

SMS Meer GmbH with its COPPER PLANTS DIVISION produces a full line of systems and machines for the processing of copper. The product range includes: shaft melting furnaces, anode casting lines, horizontal and vertical casting lines, casting and rolling lines for copper wire rod and strip, cold pilger mills, planetary rolling mills as well as tube drawing equipment. The new designed shaft furnaces are the most economic way of copper melting. The CONTILANOD® system with hydraulic shear represents a breakthrough into higher production capacities and improved geometrical accuracy of anodes. The new generation of CONTIROD® lines with individual drives of rolling stands guarantee cost effective production of highest rod quality. A new horizontal continuous casting technology for the production of tube shells as feed stock for the copper tube manufacturing process ? directube® was developed and introduced into production. A first line for continuous vertical strip casting - called VERTICAST® - for higher production rates and improval quality of cold-rollable strips is in the final stage of commissioning. These innovative technologies increase product quality, reduce process costs and help for a wide use of copper in all sectors of life.

Jan 1, 2007

By Jonathan Tsang, Ali Merati, Jonathan Beddoes

Due to economic factors, many aircraft in service today have been operating for more than 30 years even though they were initially designed with a service life of 20 years. Improved damage management models are therefore needed for use in life prediction and management of the aging fleets of aircraft. Currently, the generally accepted procedure in fatigue life prediction methodologies is to back calculate the equivalent initial flaw size (EIFS) using established long crack growth data. However, it was observed from studies carried out at the National Research Council Canada that nucleation and short crack growth constitute up to -95% of the fatigue life. As a result, it seems that the significance of the short crack regime has been underestimated and must be further investigated and fully understood before an accurate holistic life prediction methodology can be realized. Unlike long cracks, local microstructural features such as grain boundary, grain size, inter-particle spacing, and texture play dominant roles in the behavior of short cracks. An extensive study has been carried out to evaluate different crack detection and monitoring techniques in the short crack regime for AA2024-T3. The results will be presented in detail.

Jan 1, 2004

By E. M. Córdoba

The effect of the Fe3+ lFe2+ redox couple on the chemical and biological dissolution of chalcopyrite was studied. All the tests were carried out in stirred flasks with 100 mL of a ferric/ferrous sulphate solution, in the absence or in the presence of bacteria (iron- or sulphur-oxidizing) and at low (35 DC) and high (68DC) temperature. The initial redox potential was controlled between 300 and 600 m V Ag/ AgCI and silver was used as chemical catalyst. The results showed that the oxidizing action of ferric ion on the chalcopyrite was controlled, in all cases, by nucleation and precipitation of jarosites on unreacted particles. The tendency of Fe3+lFe2+ solutions towards equilibrium favours the activities of both ions to be equal. Consequently, the dissolution rate was faster at relatively low redox potentials (between 400 and 500 mY) than at high values (600 mY). In this sense, the presence of ferrous ion in the system is a key factor to control hydrolysis and precipitation of ferric ion. Unlike jarosite, the elemental sulphur produced during dissolution of chalcopyrite was porous and did not act as a diffusion barrier.

Jan 1, 2007