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By Tomas Astorga

APEC, the Asia Pacific Economic Cooperation is the forum of 21 countries having approximately 56% of the total world income, and over 45% of global trade. In 1997, APEC economies produced 67% of the world copper output, 55% of gold, and over 45% of other base metals. Mining in APEC captures more than 60% of the total mining investment in the world. New and emerging economies are now appearing in the demand scenery, such as China. New trends in the international environmental regulations are posing questions related to the use of copper in different industrial and consumption applications. These may have a strong impact on future trade of copper. New applications are also appearing based in new technology fields. The paper examines the growth potential of the copper market in main consumer ad highly populated economies of APEC, incorporating analysis of various interrelated factors. It also analyses the outlook of the copper supply. Its conclusions point to the need to implement demand outlook models. Finance and economic reforms will open important avenues for trade growth in basic metals, particularly copper. Changes in the consumption patterns of highly populated countries will add to better perspectives of copper demands. The recovery of a fast pace of economic growth in the APEC region will bring new demands for copper, especially as a consequence of high tech applications. More extended policies focused in the need for developing energy efficiency programs and schemes will add to this picture.

Jan 1, 1999

By Dhanesh Chandra

In this symposium, research in the area of energy conversion is presented. This symposium has special significance, as we honor three prominent scientists from hydrogen storage research and development field. In this symposium, the majority of papers presented by international scientists and engineers are in the area of hydrogen storage. Other energy conversion papers include magnetic materials, superconductors, and thermal energy storage materials. Recent developments in light-weight high gravimetric hydrogen density hydrides have led to potential use of hydrides for onboard automobile and other applications. This, of course, is significant from environmental concerns of CO2 and other emissions from the current use of carbon based fuels in automobiles. Thus, it is becoming increasingly important to switch to cleaner alternative fuels such as hydrogen [1]. The Challenge of Vehicular Hydrogen Storage as potential hydrogen energy carriers for vehicular applications, with a driving range of approximately 300 miles, require ~5-13 kg of hydrogen stored on-board. In the United States, Centers of Excellence have been established in metal hydrides, chemical hydrides, and carbon-based materials, and abundant scientific and industrial research is being carried on metal hydrides; only some of the current research from the Centers will be reported here. The European commission, Japan Institutions, and others also have numerous hydrogen storage programs in progress. Several international collaborations have also begun between IEA and IPHE scientists to accelerate the progress of development of practical hydrides. A summary of the abstracts is included in this overview.

Jan 1, 2006

By M. Potesser

After the primary or secondary lead production the bullion lead is remelted and charged into a vessel with following refining process. The removing of arsenic, antimony and tin takes place by salt slags or oxidizing gases like air or pure oxygen. Due to the increasing lead price, Messer Austria GmbH in cooperation with the institute of Nonferrous Metallurgy at the University of Leoben have developed a new process named OXIPOT for the refining of tin, arsenic and antimony. The OXIPOT process is in principle based on purging technology with a ceramic or steel purging device. This leads to an increased retention time of the refining products due to the deeper bath level and an optimized specific reaction volume concerning the bubble size. This paper describes the process, pilot plant, and thermodynamic calculations for the optimization concerning the selectivity of element removal.

Jan 1, 2008

By Richard B. Stein

Bechtel's BEMSIM computer program is a useful tool for solvent extraction-electrowinning plant design optimization. Its power (up to 90 stream components, 240 process streams, 180 process steps) has been applied to investigate floweheet configurations in order to perform basic engineering, sizing of plant equipment and to optimize performance of commercial-size copper plants. Flowsheet variations presented include series, parallel and series-parallel extraction stages, while heat balances simulate operations in summer and extreme winter conditions. The BEMSIM program has also been applied to nickel-cobalt, gold and manganese extraction.

Jan 1, 1993

By Jiechao Liu, Lijian Luo, Yubao Ma, Bo Zhang, Yanfeng Yang, Xin Hong, Luming Liu, Jienan Liu

Reduction kinetics of stainless steel slag in iron bath smelting reduction was studied at the temperature of 1500℃ ~ 1650℃. It was concluded that the reduction process consisted of two parts. That is to say smelting reduction was controlled by stainless steel slag melting initially and by interface reaction later. In order to increase smelting reaction rate, the melting point of slag should be decreased at the first stage and adjust the liquidity of slag at later stage. Smelting reaction rate will be accelerated by means of optimize the slag content. The optimal reduction result that all most all of the chromium in slag been recovered was obtained in temperature was 1500℃, basicity of slag was 1.0~1.2, the value of Al2O3+MgO was 25%.

Jan 1, 2015

By Laura Garcia H, Juan Carlos Gonzalez Islas, Luis Garcia Lechuga, Pedro Alberto Ramirez Ortega

"Electrochemical studies were performed to silver recovery from industrial wastes (radiographic films) on litanium flat electrode using a filter press-type electrochemical reactor with vertical orientation (known as REOV-01), as counter electrode was used a mesh-type DSA. Voltammetric studies were employed to fmd the current range under which silver reduction occurs. Using chronopotentiometric studies with controlled current, homogeneous deposits were obtained on the surface of the Ti electrode, to a current of -210 mA during 120 minutes to a constant linear flow velocity of 15 Lmin-1 was achieved 97% of silver recovery from industrial wastes. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy studies corroborated the presence of silver on Ti flat electrode. In addition, the silver concentration in the solution after the experiments was 1 ppm below environmental requirements. This indicates the viability of a filter press-type electrochemical reactor with vertical orientation (REOV-01) for silver recovery from radiographic filmsIntroductionIn recent years, the industrial sector has shown an increase in the use of silver due to new applications in different areas. In sectors such as photography, the consumption of silver has declined as a result of the boom in digital photography. However, the use of silver in radiographic applications has not shown greater variation (47.16 Moz), as the image quality is essential for diagnosis in various fields, such as medicine. All the silver used in photographic applications is discarded completely (solid or in effluent). At the present, several countries have been involved in silver recovering from industrial wastes due to the economic value and environmental impact they represent. The main source of silver recovery is the wastes generated by the photographic sector. Various technologies have attempted to recover silver contained in these wastes. However, they have not fully satisfied the requirements of maximum recovery, nor environmental level (less than 5 ppm) of silver in effluents [1,2]."

Jan 1, 2014

By B. Q. Li, H. C. de Groh, X. Lu

"A fully 3-D, transient finite element model is developed to represent the magnetic damping effects on complex fluid flow, heat transfer and electromagnetic field distributions in a metallic melt. The model development is based on our in-house finite element code for the fluid flow, heat transfer and electromagnetic field calculations. The numerical model is tested against numerical and experimental results for water as reported in literature. Various numerical simulations are carried out for the melt convection and temperature distribution with and without the presence of a transverse magnetic field. Numerical results show that magnetic damping can be effectively applied to stabilize melt flow, reduce turbulence and flow levels in the melt and over a certain threshold value a higher magnetic field resulted in a greater reduction in velocity. Also, for the study of melt flow instability, a long enough running time is needed to ensure the final fluid flow recirculation pattern. Moreover, numerical results suggest that there seems to exist a threshold value of applied magnetic field, above which magnetic damping becomes possible and below which the convection in the melt is actually enhanced.1. INTRODUCTIONThe imposition of a DC magnetic field on a moving, electrically conducting fluid, such as molten metal or semiconductor melt, produces an opposing Lorentz force that results in a reduction of flow velocity in the liquid. This effect has been explored in both the semiconductor and metals industries to control natural convection and/or surface tension induced Marangoni convection as well as thermally induced flow instability during solidification processing of these melts [1-6]. A mathematical model can be of great use in developing both fundamental understanding of the fluid-magnetic field interactions in these magnetically-assisted processing systems and basic guidelines for process design, control and optimization.This paper presents a 3-D mathematical model for magnetically damped fluid flow and heat transfer in a melt cavity, which is useful for interpreting results for unidirectional solidification processes at slow solidification rate, and some preliminary results concerning the magnetic damping effects on the flow instability in the melt. The model development is based on the finite element solution of the Navier-Stokes equations, energy equations and equations for induced electric field. The model is tested against reported results and is then applied to study the fluid flow and thermal distribution in the metallic melt with and without an external magnetic field."

Jan 1, 1999

By L. A. Kazanbayev

The Chelyabinsk Electrolytic Zinc Plant (CEZP) was commissioned in 1935. Over the elapsed years the Plant capacity has been increased from 10 thousand tons of zinc (1935) to 150 thousand tons of zinc (2005). The paper describes the Plant main achievements in production updating for the last 10 years.

Jan 1, 2006

Designing rigging systems for complex castings has been more of an art than a science. Foundrymen have used thumb rules based on past experience to develop working designs. Of late, attempts are being made to formalize the procedure through the use of rule based expert systems, process modeling and other tools. Designing risers is one of the challenges of the rigging system design. Once the riser location have been determined, an optimization technique coupled with a casting simulation code can be used to determine the optimum riser dimensions. The main drawback of using a finite element or a finite difference based process simulation code along with the optimization routine is that the computation time involved is too large. Such an approach, thus, is unrealistic for practical situations where different options have to be explored and conclusions drawn in a short period of time. This difficulty has been avoided in the present work. The optimization scheme has been coupled with a modulus based solution routine to optimize the riser dimensions. The modulus calculations provide a good and quick estimate of the freezing time at different points in the casting. A functional, obtained from these freezing time values, is minimized by altering the dimensions of the riser until an optimum shape is obtained. Some examples have been included to illustrate the utility of this technique.

Jan 1, 1994

By Frustino L. Prado

For more than a century, the AAC (ammonia I ammonium carbonate) process has been applied to the recovery of various metals. A variation of it, the Caron Process was first used in the early 1940's in Cuba for the extraction and recovery of nickel from laterites. The original Nicaro plant has been in continuous operation since then. Years later the Caron process was used again in Australia at the Greenvale (Yabulu) NickelICobalt plant, commissioned in 1974. Other projects (Sered, Niquelandia, Nonoc, Punta Gorda, Albania) as well as several studies have been carried out. The Caron Process is alive and still promising. Members of our organization have been working with AAC and the Caron Process since 1952. This paper will review current approaches and potential improvements (enhancement of recoveries of Ni and Co, reduced energy consumption and maintenance simplification). Keywords: Caron Process, Ammonia, Ammonium Carbonate, Laterites, Nickel, Cobalt

Jan 1, 2004

By C. Anderson

Most applications of copper metallurgy are geared towards primary production. However, as recycling of materials is a growing industry, one future facility will rely on copper metallurgy as a means of processing precious metals. This paper will discuss the derivation of the proposed copper pyrometallurgical and electrometallurgical unit operations to be utilized in industrial recycling of secondary precious metals.

Jan 1, 1999

By Robert L. Opila

Negative electrodes for alkaline nickel-metal hydride batteries composed of MmNi3.5Al0.8Co0.7, where Mm is misch metal, have been characterized electrochermically and using x-ray photoelectron spectroscopy. The stability and rapid hydriding and dehydriding kinetics of the alloy in KOH are attibuted to a surface film. The protective surface film is shown to consist of an porous, outer hydrated layer and a dense, inner oxide layer. In addition, metallic nickel and cobalt are found throughout the film, and are presumed to form a conductive, percolative network that permits rapid electron transfer from the bulk to the solution, allowing rapid electrochemical formation of atomic hydrogen.

Jan 1, 1997

By Kwang-suk You

This paper describes the characteristics of electric arc furnace slag (EAF slag) as an aggregate of concrete along with the chemical composition, leaching concentration of heavy metals, the soundness of EAF slag and compressive strength of mortar with 20% and 50% replacements of sand. The results showed that leaching of heavy metals and soundness of EAF slag satisfied Korean environmental limit and Korean Industrial Standard for aggregates. The compressive strength of mortar increased as the replacement ratio of EAF slag for sand increased.

Jan 1, 2006

By T. Alboussiere, O. Paireau

"We have designed an experiment to simulate natural convection in a direct-chill aluminium ingot. In this experiment we induce natural convection within a hemisphere filled with liquid-metal (mercury). The device consists of a copper hemispherical bowl closed by a copper plate. The top is maintained at superheat temperature while the boundary is cooled. While the temperature measurements were found using thermocouples, the velocities were obtained using an original technical procedure that relies on MHD properties. By applying a steady local magnetic field, we measure the velocity. The distribution of temperature and velocity can be separated into a thermally stratified core bounded by thermal wall jets. These wall jets greatly influence the degree of macrosegregation in ingots.1. Natural Convection in Aluminium CastingIt is well known that the quality of the final product in aluminium casting depends on the movements within the liquid metal such as forced or thermogravitational convection. Strong buoyancy-driven flows are known to occur in the liquid metal pool of an aluminium ingot caster. These flows have a significant influence on the metallurgical structure of the ingot through the redistribution of heat, fragmented dendrites and segregated material within the pool. Macrosegregation mechanisms depend on favourable temperature and flow distributions in the sump, and these factors will determine the pattern and degree of macrosegregation. Moreover, for many years, the importance of thermally-driven natural convection in casting has been underlined (Cole & Bolling, 1965). In this way, a precise determination of the velocity and temperature fields is required in order to improve understanding of the macrosegregation mechanisms. That is precisely the aim of this paper, which provides experimental data of the flow and the temperature distributions in a natural convection experiment. We intend, with this laboratory experiment, to determine accurately the velocity field, particularly within the thermal boundary layer where the effects of the flows may have an important role in the transport of crystals."

Jan 1, 1999

By Peter Kettle

This paper describes the performance of the copper industry over a period of some two decades and examines the theme that improvements in operating efficiency have not been matched by improved returns on capital. The financial performance of the copper industry is analysed using CRU's MICA database. Regression analysis indicates a two percentage point increase in operating margins but no increase in returns on capital. The gain in operating efficiency appears to have been mainly achieved in the mid 1980s. The investment boom of recent years has resulted in a rapid increase in the industry's level of debt and gearing ratio (now some 47%). Data on 44 copper mine projects is used to show the linear relationship between scale and capital costs. Typically new capacity costs some US$5,000 /tpy. The relationship between cash costs and capital intensity of projects is also plotted. The greater attention now being focused on efficient use of capital means that capital intensity rankings will become increasingly important in determining which projects go ahead.

Jan 1, 1999

By L. B. Tsymbulov

At present data on thermodynamic properties of metallic melts, containing copper and ?iron family? metals, is rather limited. Determination of the activity of metallic melts components under high temperature by experimental methods requires high level of labour inputs. With this it is not always possible to obtain the results with high level of accuracy. Due to that in a number of cases it is more appropriate to apply different methods of analysis, with the help of which there can be calculated thermodynamic properties of ternary and even more complicated systems, prominent thermodynamic properties of binary systems being used as a basis for these calculations. This work presents the results of calculations of different components activity and activity ratio in such ternary system melts as Ni-Cu-Fe, Ni-Cu-Co, Fe-Cu-Co and Fe-Co-Ni. Good compliance of calculations results with those obtained in the course of reliable experimental investigations fulfilment is demonstrated. There are presented the results of activity and activity ration analysis for some compositions of Cu-Ni-Co-Fe system.

Jan 1, 2006

By Taner Kavas

In the present study the utilization of coal ashes that appear at the end of firing process of brick production in cement pastes was examined. Ashes with three different particle sizes of 75 µm, 106 µm and 150 µm were used to replace ordinary Portland cement (PC) as 5 % and 15 % by weight. Seven samples were prepared and physical, mechanical, chemical and microstructural analyses were carried out. The compressive and bending strength values of samples were determined at the ages of 2, 7 and 28 days. It was found that cementitious pastes with finer particle sizes possessed the highest compressive and bending strength values at all curing ages. Both values after 2 and 7 days cure increased with an increase in ash content, no matter what the particle sizes of ashes were. However, strength decreased after 28 days cure as a result of ash addition of 15 %, although it was still above that of the PC.

Jan 1, 2006

By Sergio Demetrio

Based on the current reality of the copper smelters industry, besides the advances that have been and are expected for the next few years, the authors present a futurist vision of the processing of copper concentrates and copper smelters in the years 2000. Outlined new development strategies and ways of improvement in this business, including research, development and management of the works that today posses characteristics of a profitable operation, as well as the changes expected with respect to the entry of new actors and the creation of new products The authors finally bet for small or tailor-made smelters with ad hoc technology for their raw materials and few units to coordinate -devoted to specific concentrates using high technology and low manpower. Considering the in-situ hydrometallurgical route, as well as the pyrometallurgical route in works or conversion facilities that buy or process white metal and produce copper and other metals associated with this such as gold and silver, besides sulfuric acid, plants which should be strategically located in zones with high sulfuric acid price to make this a product which contributes to the profitability of the business.

Jan 1, 1999

By Bo Zhou

During secondary aluminum recovery, complex aluminum scraps are melted and refined often in a rotary melting furnace and the aluminum metal has to pass through a molten salt layer and melt down in a bottom aluminum bath. Previous experimental study and industrial observations have indicated that salt shell formation and re-melting on the metal solids in the early stage plays a critical role in the overall melting process of the scrap. In the present paper, mathematical models are developed to simulate the process of salt shell formation and its re-melting, as well as aluminum melting in the molten melt. Influence of the salt layer properties, the residence time of the metal particles in the salt layer, the particle size, the temperature of bulk melt were investigated. Reasonable agreement with the measurement data was reached. The developed melting model will be used to construct a population balance model of the scrap melting behavior for a rotary melting furnace, taking into account the distributed characteristics of the scrap. Finally, an overall process model based on Computational Fluid Dynamics (CFD) for the rotary furnace will be constructed, coupling with the population balance model for the scrap melting.

Jan 1, 2003

By Norbert L. Piret

During smelting of copper, arsenic in the feed reports to a large extent to the gas phase and some enters the anode copper. From the gas phase it is transferred during wet gas cleaning directly, or indirectly after dust processing, to aqueous solution. During the electrorefining and anode slimes processing, the anode arsenic content is also transferred to aqueous solution. Technology for the efficient removal of arsenic from process streams and cleaning of aqueous effluents is well established. However, the arsenic-bearing products, which thereby are generated, can vary widely in consistency, quality and quantity, from large amounts of gypsum contaminated with water-soluble arsenic compounds to residues with high arsenic content ' or arsenic products. Arsenic management in a copper smelter not only is involved with the duty of compliance to the gaseous and aqueous emissions standards but also should have as objective the minimization of the generation of arsenic-bearing and, in general, heavy metal-bearing solid waste. The present paper outlines options and the associated economic aspects for minimization of arsenic-bearing solid waste generation, for improvement of the environmental compatibility of the residues to be deposited and for the .production of commerciable arsenic compounds under appropriate market conditions.

Jan 1, 1999