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By B. J. Beaudry

Intermetallic compounds are frequently required in the form of thin sheets for magnetic refrigeration and other applications. Progress has been made in the preparation of thin sheets of brittle gadolinium intermetallic compounds by hot rolling of sheathed billets. The effect of fabrication procedures on the Curie temperature of GdPd and its heat capacity at low temperatures has been studied.

Jan 1, 1989

By Manuel Pérez-Tello

A mathematical model to represent the expansion and fragmentation of copper matte particles oxidized under flash converting conditions is presented. The model assumes the particles to be initially nonporous, have a constant mass prior to fragmentation, and travel at a constant velocity throughout the reaction chamber. The model requires the specification of five parameters: the particle expansion rate, a fragmentation diameter factor, a fragmentation size distribution parameter, and the fractions of the finest and the coarsest particles in the feed that undergo fragmentation. The model predictions show good agreement with experimental data collected in a laboratory flash converting furnace over a wide range of experimental conditions. The evolution of the size distribution of the particles along the reactor length was computed, and the model parameters were correlated with the experimental operating variables. Model predictions indicate that particle residence time is an important factor in the generation of dust. The presence of two maxima in the particle density function may be attributed to turbulent conditions prevailing in the furnace, which cause particles to follow very different trajectories within the furnace even if they are injected at the same location.

Jan 1, 2006

By Daniel Kim, Michael Free, Justin McAllister, Urian Marshall, Shijie Wang

"Cathode impurity levels of electrorefined copper were evaluated based on 1/10* scale laboratory electrorefining tests. Cathodes were evaluated near the top, mid-section, and bottom sections of cathodes on both the set and mold sides and strip and scrap cycles. Slime weights were measured, and slime and electrolyte samples were also evaluated for impurities. Results from these tests have been compiled and compared to evaluate the effects of changes in operating conditions and electrode location on cathode impurities.IntroductionMany types of impurities are commonly found in commercial copper electrorefining anodes. The smelter operations that produce the anodes process concentrates that contain a wide variety of impurities that vary based on the mineralogy of the ore. Most anode impurities are removed during electrorefining. However, a portion of the anode impurities is incorporated into the copper cathode product. The mechanisms by which impurities are transported from the anode to the cathode are not well understood. Some impurities can be transported as anode slime particles to the cathode where they are incorporated into the cathode. Other impurities can be transported as dissolved species that are electrochemically reduced with the copper to become part of the cathode. Although research has been performed on anode slimes and impurities [1-4], there is a need for additional information regarding the relationships associated with electrorefining cycles, electrode faces, local electrode positions, anode impurities and specific cathode impurities. The objective of this study was to evaluate lead, arsenic, and antimony cathode impurity trends associated with electrorefining cycles, electrode faces, local electrode positions, and anode impurities. A variety of techniques including electrolyte filtering, anode heat treatment, high electrolyte arsenic concentration, high arsenic and/or lead in anodes, flocculation of slime particles, and appropriate current density control were used to vary cathode impurity levels. Each test was performed only once for a strip cycle and once for a scrap cycle. Consequently, the results for the individual conditions are preliminary and are not the focus of this study. However, the collective set of data with varying impurity modifying techniques provides a broad range of impurity levels, and the associated trends with respect to lead, arsenic, and antimony are discussed in this paper. Approximately 180 analyses of copper cathode were used to track the antimony, arsenic, and lead impurities. Eighteen anode slime samples were also analyzed for antimony, arsenic, and lead."

Jan 1, 2012

By Daniel S. Gwinner

The tolling, or processing for a fixed fee, of aluminum drosses to recover the metal units is a common practice in the Aluminum Industry. The Dross Toller is acting for the owner, and since most dross processes result in material going to landfill, it is important for the owner of the dross to insure that the toiler is processing the material and handling waste disposal in an environmentally responsible manner. The paper discusses the Dross Toiler Audit Program, first from the Reynolds Metals Company perspective. Included are the reasons the company deems it necessary to audit and a description of the items covered during the audit. Finally, there will be a discussion of the audit from the Tollers perspective - what the Toiler can expect when the auditor arrives.

Jan 1, 1995

By V. M. Paretsky

Most recent developments made in the Gintsvetmet Institute in the field of technologies and equipment for single-stage autogenous smelting of copper sulfide raw materials to produce white metal and blister copper on the basis of oxygen-flame smelting process and separation of highly basic calcium-containing slags have been discussed. This technology includes the oxygen-flame smelting process (KFP Process) to produce highly basic self-disintegrating ferrite-calcium slags with their subsequent flotation to recover copper and a basically new sparging smelting process (FBP Process) to produce combined slags subjected to decopperizing inside the same furnace. Results of special investigations of the slag structure obtained in the KFP and FBP processes and substantiating selection of their chemical and phase composition have been presented. It has been demonstrated that the above processes meet the stringent world-level requirements to advanced technologies with respect to energy conservation and environmental safety with different scales of production and within a wide range of specific conditions of particular operations.

Jan 1, 2006

By Kimura. E.

Continuous estimation of phosphorus content of molten copper is required to produce phosphorus deoxidized copper in a continuous casting operation. The phosphorus content of molten copper was related to its electric resistivity, which was measured by the four-probed technique with a specially-shaped cell. In a laboratory scale, the linear relationship between the above factors was confirmed in the temperature range of 1083OC through 1200°C. The phosphorus concentration range measured was from 40 to 500 ppm. The phosphorus content was monitored successfully by measuring the electric resistivity of the molten copper in the distributor of a continuous caster in an industrial scale.

Jan 1, 1992

By Donald R. Sadoway

Fused salt electrolysis is used extensively in the primary extraction of metals (electrowinning), in the refining of metals (electrorefining), and in the formation of coatings (electroplating). In the case of rare earths, fused salt electrolysis competes with nonelectrochemical processes to make the same products. However, fused salt electrolysis has the potential to produce these metals in a variety of technologically useful forms: thin films and epitaxial layers, powders, and a variety of nonequilibrium structures. The theory and practice of fused salt electrolysis as it applies to the extraction, refining and plating of rare earth metals are described. The potential of fused salt electrolysis to synthesize advanced materials containing the rare earth elements is assessed.

Jan 1, 1989

By John D. Kinton

A patent is a right granted by the government to exclude others from making, using, selling, offering to sell, or importing a claimed invention. Once the right is granted, the patentee may use the U.S. Federal Courts to enforce that right. Reading a patent from a litigation perspective is quite different than reading it from a technical perspective. The Judge's interpretation of the claims will affect their scope, and likely the ultimate outcome of a patent case. Additionally, the patent right can be challenged. If done successfully, the patent can be rendered invalid or unenforceable. The likelihood of success, and well as the achievement of other litigation goals is often influenced by the forum where the litigation is initiated. Finally, patent litigation costs are significant, and will weigh heavily in the decision to file (or fight) a patent lawsuit.

Jan 1, 2006

By Zbigniew Smieszek, Ryszard Chamer, Ryszard Prajsnar, Zygmunt Kurek

"Lead-containing wastes processed at the IMN’s Division in Legnica originate mainly from dry and wet dedusting installations of the technological lines for copper production. These are lead dusts and lead-zinc dusts characterised by the specific properties resulting from the chemical composition of the Polish copper concentrates. Besides lead, they contain many accompanying metals and impurities such as zinc, copper, sulfur, chlorine, potassium, sodium, and also bituminous substances. Processing of lead-containing dusts is conducted in the installations of rotary-rocking furnaces heated with gas-oxygen burners fitted with auxiliary systems for cleaning process gases and refining re-circulating dusts. The processing technology utilizes innovative process and technical solutions enabling disposal of lead-containing wastes from copper metallurgy and from non-ferrous metals industry according to the BAT recommendations and to the guidelines specified in integrated permission. In this paper, the main technological aspects of processing lead-containing dusts at the IMN’s Division in Legnica have been presented.IntroductionCrude lead is obtained in Polish lead metallurgy from various primary and secondary materials, such as Zn-Pb concentrates, lead-bearing dusts of copper metallurgy and battery scrap. In zinc smelter Miasteczko Slaskie S.A. crude lead is produced from sulfide and oxide Pb-Zn concentrates in ISP process. Orzel Bialy S.A. and Baterpol Ltd. produce crude lead in short rotary furnaces in the process of smelting products of mechanical battery scrap separation– desulfurised or not desulfurised paste and metallic fraction. KGHM Polska Miedz S.A. and IMN Divison in Legnica produce crude lead in rotary furnaces in the process of smelting of polymetallic dusts and slimes from copper production processes."

Jan 1, 2008

By W. Gong

Their outstanding thermal stability and high energy product make Sm(Co,Fe,Cu,Zr),-type alloys attractive for advanced applications. The near net-shape production of Sm(Co,Fe,Cu,Zr), bonded magnets make them potentially superior to any magnets made by sintering. Although pioneering work done by Shimoda et al. and other investigators provide insights on the proper compositions and process control of this alloy system, additional work is still necessary to improve our understanding of alloy behavior at various processing stages and to increase the production yield during powder processing. In this paper we report on the development of anisotropic Sm(Co,Fe,Cu,Zr), alloy powders for the bonded magnet application. Our focus is on the development of a moderate coercivity powder requiring a relatively low magnetizing field to charge the magnets to their optimum Br, Hci and BHmax. The magnetic properties are related to the evolution of the microstructure at various processing stages and the average particle size and size distribution of powders.

Jan 1, 1997

By L. M. Bianchi

"Oxide, nitride and other compound coatings often do not have adequate properties for newer applications when produced using very high deposition rates and simple evaporation techniques. Solar control, abrasion resistance, low reflectance and barrier effective engineered coatings require exacting properties. Such properties can be obtained by adapting the activated reactive evaporation (ARE) technology to Web production processes. Adaptions of the HAD and MAD processes will be described along with data on the high deposition rates obtained. These fast production capabilities were developed in order to make the processes economically competitive.IntroductionThe Physical Vapor Deposition technique (PVD) has been used to coat steel strip for over 20 years. (1) However, its use as a production process has been very limited because of the high cost of the PVD coating process and because, in some instances, the properties of the coating were not good enough to meet the customers requirements. Nevertheless, the PVD process has found wide application in the airplane engine and electronic component markets. These production processes have stimulated further development and advances in the technology.In 1971, Profession R. F. Bunshah developed the Activated Reactive Evaporation (ARE) process which was then used to produce hard coatings such as carbides, nitrides, oxides and other refractory compounds. (2) The process from a fundamental viewpoint -produces a coating on the substrate via the evaporation of metal in the presence of a low pressure (typically around 1 millitorr) of reactive gas, with a plasma created in the space between the metal source and the substrate.The plasma may be created by many means but its function is two-fold. First, it activates the reaction between the metal vapors and the reactive gas atoms/molecules resulting in the formation of a compound that deposits on the substrate. Second, because the plasma is in contact with the substrate, it results in a negative bias on the substrate and produces bombardment of the growing film with ions and energetic neutrals from the plasma. This bombardment causes many significant changes in the microstructure, properties and appearance of the coating.Recently another new technology Pulsed Magnetron Systems (PMS) has been introduced into PVD. This new technology has been pioneered in production scale equipment by Dr. S. Schiller (3) and associates. The use of a pulsed power supply on the magnetron prevents the problem of the anode being coated with a insulating layer which will then lead to micro and macro arcing producing defects in the coating."

Jan 1, 1998

By D. Ducharme, J. Lenz

Operation of the Kidd electrolytic zinc plant commenced in 1972 with a cellhouse capacity of 105,000 tonnes of zinc cathode. The original cellhouse layout consisted of 42 parallel rows for a total of 588 cells. As leaching capacity increased, the cellhouse was expanded to 630 cells. Zinc cathode was manually stripped from plant start-up until the development of a mobile automated stripping system in 1994. Machine development continued until a second unit was placed in production in 1996, from which point, 60 % of the cellhouse was being stripped with the automated system. The final phase of the project was implemented in 1999 with the commissioning of two more automated strippers. This paper describes the implementation of the automated stripping system and its impact on cellhouse productivity.

Jan 1, 2000

By Daojin Cao

The chemical components in the saturated aqueous solution of ammonium dimolybdate (ADM) were investigated at room temperature by comparative Raman spectroscopy. In order to explore the further detailed results, a new method of qualitative and half quantitative analyses, based on the main vibrant frequencies and the intensity ratio of the strongest peak to the second strongest peak recorded in Raman spectrum of saturated aqueous solution of ammonium heptamolybdate tetra hydrate (AHM), was put forward and attempted to analyze the chemical components of saturated aqueous solution of ADM. The results showed that there was obvious difference between Raman spectrum of saturated aqueous solution of ADM and that of ADM, but there were good relationships between Raman spectrum of saturated aqueous solution of ADM and Raman spectra of the three samples including AHM, the saturated aqueous solution of AHM and monomolybdate ion in aqueous solution. It was found that aggregated dimolybdate ion ({Mo2O72-}n)did not exist in the saturated aqueous solution, and was changed into heptamolybdate ion (Mo7O246-) and monomolybdate ion (MoO42-), which were in equilibrium each other, but the distribution ratio of heptamolybdate ion was larger than that of monomolybdate ion. In addition, Raman spectral pattern of saturated aqueous solution of ADM was reported.

Jan 1, 2006

By G. St-Amant, V. Cloutier, E. Ghali, S. Jin, G. Houlachi

During the casting of lead-silver anodes, variations in cooling rates result in the formation of an uneven microstructure. The slowly cooled areas (SCA) have a coarser microstructure than that of the remaining part (called "the general zone"). The effect of anode microstructure on the electrochemical behavior was investigated using galvanostatic, potentiodynamic and electrochemical impedance techniques. The results show that the resistances for the two steps of the oxygen evolution reaction on the slowly cooled areas of Pb- Ag anodes are higher than that on the general zone. The double layer capacitance for the first step of the oxygen evolution reaction (OER) and the pseudocapacitance of the second step of OER on SCA are smaller than those on the general zone. The potentiodynamic results show that the amount of lead dioxide formed on the SCA is greater than that of the general zone of the anode. The potential decay curves after 30 minutes of galvanostatic polarization at 45 mA/cm2 show that the corrosion potential of the SCA is 200 mV lower than that of the general zone. This can lead to perforation because of the formation of a galvanic cell with a small anode and a large cathode.

Jan 1, 2000

By Emilia Visileanu, Eftalea Carpus

"Due to the demographic explosion and development without precedent of the consumer society, the capacity to destroy the ecological balance the entire planet life depends on, acquire new dimensions. In this context new approaches on society development are imposing as well as special responsibilities for stopping and preventing Earth destruction and repairing the damage already done. The zero waste is a call to action that has as an aim the changing of current mentality of human society. ”take, use, throw away”. The zero waste is a policy, a way, an aim and represents a new approach planned for the XXI century that include the resources preservation principles, pollution reducing, increasing of the opportunities to create new work places and providing the highest degree of the.1. INTRODUCTIONThe zero waste is a call to action that has as an aim the changing of current mentality of human society. ”take, use, throw away”. The zero waste is a policy, a way, an aim and represents a new approach planned for the XXI century that include the resources preservation principles, pollution reducing, increasing of the opportunities to create new work places and providing the highest degree of the economy stability.2. ECOLOGICAL CONCEPTSA long-living Romania means:The closing of the production cycles, by waste reusing and recycling; the reducing of the use of fossil fuel; the improving of the material qualities, for extending the economical life of the products made by these materials; the reducing of the transport traffic.In this context, ecology, the star science with the ability to conserving and renewal of the environment is making its way, having the following principles:•,everything is bind by everything – is referring to the importance which the environment has for a great number of allied fields;•,everything leads to somewhere – the principle of the indestructible property of material (in nature, there must not exist wastes);•,nature does it the best – ecology becomes the responsible science with the governing of the strategic laws between man and nature, man takes advantage of the natural resources which he cannot create by himself and nature must feel guarded and not destroyed by this alliance;•,nothing is for free – the polluter pays.The protection of the natural environment means:•, its strong knowledge and that of the interactions between the social economic system and the natural system, the foreseen of the most close and most distant consequences of these interactions;•,the rational usage with maximum economical character of the natural resources not depending on their origin;•,preventing and direct fighting against as well on the degradation of the environment caused by man, as on those produced by natural causes;•,the ability to harmonize immediate interest of the human society on long and permanent term, using the natural factors of the environment."

Jan 1, 2008

By Oleg I. Platonov

Method of high-temperature reduction of oxygen-bearing sulfurous gas has been developed at Copper Plant (CP) of MMC ?Norilsk Nickel? Trans-Polar Division (PD) with the aim of producing elemental sulfur from Vanyukov furnace? off-gas. Non-explosive reduction technology of oxygen-bearing sulfurous gas by methane utilized at Copper Plant has been designed to separate the processes of gas heating and sulfur dioxide reduction based on different kinetic of the reactions oxygen fixing and SO2 reduction. First, natural gas promptly reacts with oxygen contained in the process gas to heat a gas mixture up to the temperature of sulfur dioxide reduction (1200C). Then isothermal reduction takes place within 1 sec. Combustion chamber (pre-chamber) design developed based on the above principles is presented. Practical experience of the two reduction reactors operation at CP since 1996 proves high efficiency of the developed reduction process. The volume efficiency rises dramatically thanks to the fact that both fuel and reducing agent are fed into the reactor volume in the form of high-speed turbulent jets providing an intensive mixing of the reacting gases. On condition of equal internal volume of the reactors, the developed process offers higher efficiency of reagent interaction resulting in sulfur conversion exceeding 90%, as compared to the equilibrium one.

Jan 1, 2006

By Liping Li

A comprehensive three-dimensional two-phase mathematical model was developed to represent a channel type reactor with intense bottom gas agitation. Tracer dispersion and particle tracing methods were used to conduct the analysis based on the solution of the Navier-Stokes equations. Different operational parameters, such is gas volume flow rate. bubbler separation aspect ratios and liquid Input flow rates, were investigated for the purpose of reactor optimization. The numerical calculations were compared with experimental results obtained at the University of Missouri and a good general agreement was observed. Relatively low longitudinal mixing was observed characterizing the system as a "plug-flow" type reactor, in contrast to the intense vertical mixing, under the conditions investigated. Some general mixing characteristics are also discussed In connection to the behavior of other metallurgical reactors.

Jan 1, 1996

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

By Richard LeSar

Sustainability requires more from engineering than the development of technology. Engineering must also take into account the effects of that technology on the integrated social, economic, and environmental processes that constitute our society. Schumacher introduced the powerful concept of an appropriate technology, by which he meant a technology that is appropriate to the environmental, educational, cultural, and economic situation for which it is intended. While the principles of appropriate technology have been most commonly applied in the developing world, they are equally valid in the developed world as well. In this paper we will review appropriate technology and discuss its role in helping to define a way to think about this broad view of sustainable engineering. We will end by presenting one strategy for introducing the concepts and applications of appropriate technology in an engineering curriculum.

Jan 1, 2010

By John Hollow

The Fort Knox Mine is an open-pit operation, located in Alaska, which started commercial production in March 1997. A conventional Mill processes 38,000 tpd of a low grade (1.0 g/t Au) free milling gold ore with a low sulphide component (below 1%). Gold production (11% from gravity and 89% from cyanidation) exceeds 400,000 ounces per year. Short retention time (20h), low temperature (7oC) and low grade make high leaching kinetics critical for the performance of the process. In April 2001, the treatment of True North ore, which represented 14.4% of the mill throughput and contained more sulphide in the form of pyrite, arsenopyrite and stibnite, resulted in a substantial drop in the average gold extraction from 87% to 72.6%. Laboratory investigations indicated that the addition of lead nitrate increased gold extraction to 91.7%. Further investigations were initiated to determine the leaching parameters and the nature of the problem. Subsequently, a lead nitrate addition scheme was implemented at the Fort Knox Mill that resulted in 2002 gold production being in excess of 31,000 ounces higher than that estimated for the non-lead nitrate reagent scheme. This paper presents the results of laboratory investigations and modifications in plant operating practices.

Jan 1, 2003