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By C. Niedersberg, M. K. Almeida, R. M. C. Santana, V. G. Dalenogore

"The major source of environmental pollution in urban areas is the transport sector and its impact on human health and the greenhouse is preoccupying. In many works of literature is monitored the pollutants in urban cities, however in specific areas such as universities, they are scarce. Therefore, the aim of this work is to monitorate the gaseous pollutans in a bus terminal at Santa Cruz do Sul University-UNISC and to develop a control framework of the air quality. Six points were selected for monitoring, being one of them inside a bus. The monitoring of CO, HC and CO2 were carried out on arrival and departure of the bus. Preliminary results conducted in a day of spring showed that the most critical condition was during the night shift, where the concentration of CO (200 ppm) was the highest, caused by the vehicles increase, due to the larger number of students.IntroductionAccording to Mascarenhas et al, 2005, air pollutants are responsible for various effects on vegetation, ecosystems and is recognized as one of major public health problems of today, with harmful effect on humans even at levels considered safe by Brazilian legislation.There are numerous scientific papers linking air pollution with respiratory problems, cardiovascular which hinder the daily life because many of these diseases are chronic and may even lead to death, as was noted by Brook et al, 2004.There is a significant increase in the last decades of emissions to air resulting mainly from human activities. Already being observed the relationship of these emissions with the change in global climate, IPCC, 1995.They are a multitude of pollutants from the atmosphere, and its sources and its effects. The effect of Greenhouse gases (GHG), representing less than 1% of the gases in the atmosphere, controlling the flow of energy in the atmosphere. The increase in emissions of greenhouse gases is affecting the Earth's average temperature, which depends on the balance between these flows, in particular the flow of solar radiation reaching the surface and the flow of infrared radiation sent into space.One of the main greenhouse gases to this imbalance is the gas methane (CH4). Methane is produced by anaerobic decomposition of organic substances, through the action of bacteria metanogenic conditions that require highly reduced to its growth. This gas is released into the atmosphere mainly by transport diffusive by aerenchyma (vascular tissue) plant and also by diffusion through the water slide. (Bont et al., 1978)."

Jan 1, 2008

By Fu-Shen Zhang, Mengjun Chen, Jianxin Zhu

"In the present study, different types of cathode ray tube (CRT) glasses were examined by sequential extraction combined with TCLP to provide possible explanations for how Pb and Ba leach out from the waste CRT glasses and to give possible reasons for why they leach out. Sequential extraction results showed that Pb and Ba in the CRT glasses dominanfly presented as the residual fraction. The exchangeable fractions of Pb and Ba were extremely low, less than 0.01 % of the total content, but they were higher than those required by the regulation limits, 5 and 100 mg/L for Pb and Ba, respectively. TCLP tests of the original CRT glasses and CRT glasses residues after each step of sequential extraction demonstrated that the extremely high leaching toxicity of CRT glasses mainly caused by its exchangeable and carbonate fractions of Pb and Ba.IntroductionIn recent years, the amount of cathode ray tube (CRT) contained monitors or TV sets in the market were sharply reduced, since they were substituted by novel and better electronic and electric equipments such as LCD and PDP, leaving huge amount of end-of-life CRTs. 50-85% of the total weight of this kind of computer monitor or a TV set is glass[1,2], which was classified to three categories according to their chemical compositions: black & white glass (BW), color panel glass (CP) and color funnel glass (CF)[3]. In order to provide shielding from X-rays generated during the picture projection process, lead, barium and strontium oxides were used in the glass. In general, a color CRT contains 1.6-3.2 kg of lead . Therefore, these glasses have attracted wide and tense attention due to the potential risk to the environment and human health."

Jan 1, 2011

By Roberto Parra, Roberto Parada

"A novel process for minor elements control in copper pyrometallurgical production is proposed based on a theoretical analysis and the results of an experimental program. Its application can solves operational problems related to volatile elements that determine pollutants gas emissions and the final quality of anodes. The process considers a calcination of mixtures of the dust with sulfidizing agents such as dirty copper concentrate or elemental sulfur at temperature under 800 °C. The product are a clean calcine that recovers all the Cu content on the dust and a gas stream that collect the minor elements as sulfides species. The calcine can be returned to the smelter avoiding the As increasing in the circuit and so on, the capacity for the treatment of dirty concentrates for the smelter can be higher. The possibility to apply vacuum in the calcinations step can decrease the operation temperature. The solid condensed from the gas has different options for its stabilization, with the advantage that this stream represents few mass with high As content.IntroductionThe control of undesired minor elements (IVIES) in conventional pyrometallurgical copper production is especially relevant for ore deposits associated to Andes region. The concentrates that are being produced present every time higher levels of volatiles and harmful elements: group Va (As, Sb and Bi), Pb, Zn, and Sn."

Jan 1, 2008

By Anatoly Sudnev, Vladimir Skorohodov, Igor Kudryavtsev, Boris Radionov, Dmitriy Panov

"In cobalt production technology at a stage of solutions purification manganous cake (slime) basically containing hydroxides of the specified metals is formed. The possibility of full cobalt recycling in the basic technology of metal production at slime processing with generation of pure manganous compounds is shown. After slime dissolution in sulfuric acid in the presence of reducers the solutions containing cobalt, manganese, nickel and other nonferrous metals are formed. Optimum conditions of selective precipitation major part of cobalt by sodium hydroxide from the obtained solution are defined, thus more than 95% of manganese are remained in the solution. The cobalt precipitate is directed to the basic technology and the solution is purified by sorption. The most effective sorbents are chosen, optimum modes of its use are found. Examples of manganese recovery from the purified solutions as MnO2, MnCO3, Mn(OH)2 with a ratio manganese : impurities more than 3000 are presented.In the processes of hard alloys manufacture and processing of cobalt-bearing primary raw materials various cobalt-manganous slimes are formed. After leaching by solutions of mineral acids the problem of cobalt and manganese separation becomes an actual. The common way of metals separation in a solution is the Shreyber’ alkaline method allowing rather selectively to precipitate of cobalt hydroxide by sodium hydroxide. However this way does not allow separating completely target metals because of transfer of some manganese in the hydrated precipitate, even at its rather low content.In the given work the results of researches to improvement of a traditional way by inclusion to hydrometallurgical technology of operation of sorption separation of the specified metals are presented. The main goal is definition of conditions to achievement of the complete removing cobalt at hydrolysis with the minimum sedimentation of manganese and the subsequent additional recovery of cobalt by ionites from the obtained solutions."

Jan 1, 2008

By J. W. Perez

In the treatment of process effluents containing metal ions, it is sometimes desired to remove all of the heave metal ions while at other time it is, desired to remove one heavy metal ion from another, selectively. Ion and precipitate flotation processes were evaluated to perform these functions using the copper-iron aqueous system as a model. Because preliminary foam fractionation experiments proved to be relatively inefficient, most of this work has focused on precipitate flotation using both hydroxide and sulfide precipitation. Test results indicate that by proper control of reagents and operating conditions, it is possible to substantially reduce the froth volume over that achieved with foam fractionation and to separate copper from iron selectively. Mechanisms for collector attachment to precipitates were studied.

Jan 1, 1992

By Heinz Boeni, Daniel Ott, Uca Silva

"Latin America is facing a rapid increase in internet use. Penetration with electronic equipment is in some countries approaching the level of industrialized countries. There is an evident need to resolve the management of “end-of-life” computers and other electronic equipment. Several studies in Latin America assessed the increasing e-waste quantities and confirmed the importance of a sustainable e-waste management. This paper gives an overview on the status on e-waste management in Latin America, explains the challenges for establishing an e-waste management system in a developing country setting and highlights the social and economic potential and the possibilities of a regional approach.IntroductionGlobal ICT-Trade and generation of e-waste from ICTThe global production of electronic devices and particularly of Information and Communication Technologies (ICT) faces the biggest industrial expansion of the history: OECD figures show that global trade of ICT technologies has reached 7.7% of the gross world product by 2004, the major proportion accruing from China [1]. In 2006 an estimated 230 million computers and 1 billion cell phones have been sold worldwide which corresponds to a volume of 5’848’000 t [2]. As a consequence, Waste from Electrical and Electronic Equipment (WEEE), or e-waste, is by far the fastest growing waste component. It reaches more than 5% referred to Municipal Solid Waste and e-waste generation in developing countries according to UNEP is expected to triple by 2010 [2].According to the OECD e-waste is “any appliance using an electric power supply that has reached its end-of-life” [3]. The European WEEE directive [4] distinguishes 10 categories of ewaste: Big household appliances, Small Household Appliances, IT and Telecommunications Equipment, Consumer Equipment, Lighting Equipment, Electrical and Electronic Tools, Toys, Leisure and Sports Equipment, Medical devices, Monitoring and Control Instruments, and Automatic dispensers. In this paper e-waste and WEEE are used as synonyms. Focus will be laid on e-waste from IT equipment (IT-waste), corresponding to category 3 of the European WEEEDirective."

Jan 1, 2008

By M. Sripathy, K. V. Sharmal

"The conventional fiber reinforced plastic does not participate in the plastic deformation or enter the large plastic deformation state during collision. On the other hand, sandwich structure allows more plastic deformation, which improves the energy absorption efficiency. The objective of this study is focused on the investigation of the crushing of sandwich structure made from sisal / coir / bamboo/ glass fabrics as reinforcement and with polyester resin to form the composites skin and with polyurethane foam as the core. Experiments were conducted, showing that the underlying crushing mechanism of sandwich structures is very different from that of solid-section thin-walled structures. When a sandwich is subjected to crushing, the core deforms in the shear mode and the face bends independently. The damage is through the width zone of crushed foam core accompanied by a residual crushing in the foam. It is shown that such damage causes a significant reduction of compressive strength. Results show that glass/polyester and bamboo/polyester skin based sandwich structures have superior compressive strength. Coir /polyester based sandwich structure come next to glass/polyester sandwich structures in this aspect which is then followed by Sisal /polyester based sandwich structures.IntroductionCellular polymeric foam sandwich structures are often employed in shock mitigating applications. The cellular polymeric foam has several favorable properties, such as, low density, relatively high strength-to weight ratio and a significant degree of crushability. This high crushability is the result of the large void ratio in such materials, which also facilitates the collapse of cell walls via bending and buckling [1]. A few feasibility studies on FRP sandwich panels show that the panels efficiently provided high mechanical performance for minimum weight [2]."

Jan 1, 2012

By Maria Cristina Ruiz

The removal of iron from the leaching circuits is a common problem in the hydrometallurgical processing of non ferrous metals. Among the currently available processes, hematite precipitation is the most recommendable from an environmental point of view. This paper is concerned with the batch precipitation of hematite from ferrous sulfate solutions. One of the main objectives of the study was to determine the effect of the experimental conditions on the extent of iron precipitation as well as the purity and the particle size distribution of the precipitates. The main variables studied were temperature (180 to 220 ºC), concentration of sulfuric acid (1 to 10 gpl), initial iron concentration (1 to 15 gpl) and partial pressure of oxygen (3 to 7 atm). The results showed that increasing the oxygen partial pressure from 3 to 7 atm produced a very small increase on the rate of hematite precipitation indicating that a large partial pressure of oxygen is not needed for an effective ferrous to ferric oxidation. An increase in the temperature produced finer precipitates with lower sulfur contents. On the other hand, an increase in sulfuric acid concentration and initial iron concentration produced precipitates with larger particle sizes and higher sulfur contents.

Jan 1, 2006

By Yang Tian-zu

Sodium pyroantimonate which is widely used as the clarifier in the glass industry and as the synergist in anti-flaming industry respectively has a production history of about 30 years in China. At present there is the production capacity of about 20,000 tons per year in China and China is chief producer of sodium pyroantimonate. In this work the production processes adopted by the producers of China, the operation conditions and the product qualities of sodium pyroantimonate prepared by different preparation methods have been summarized, and on the basis of comparing the advantages and disadvantages for each process the most advanced method - the air-oxidation method was introduced in detail. The production processes of sodium pyroantimonate mainly include the method of oxidation by sodium nitrate, the oxidation method of hydrogen peroxide, the potash salt method, the chlorination method and the air-oxidation method etc. The method of oxidation by sodium nitrate in which the crude antimony oxide, sodium carbonate and sodium nitrate are separately used as the raw material, the flux agent and the oxidant, has the advantage of short and simple technological process, but low grade quality of sodium pyroantimonate and bringing about serious environmental pollution are the disadvantages and this method has been substituted by other methods. Sodium pyroantimonate can be directly prepared by the hydrogen peroxide oxidation method with the advantages of simple technological process, high grade quality of the product and little environmental pollution. High grade quality of sodium pyroantimonate can be also synthesized by the potash salt method, in which industrial antimony white, the hydrogen peroxide, potassium hydroxide and sodium hydroxide are applied as the starting material. The disadvantages of these two preparation methods are high production cost and high requirements on the raw materials. The chlorination method with the crude antimony oxide, hydrochloric acid and chlorine as the raw material has the advantages of low production cost and high grade quality of the product. However complex process, high requirement of anti-corrosion for the equipments and producing plenty of waste water limit its application. The air-oxidation method with stibnite/jamesonite concentrate, sodium sulfide, and sodium hydroxide as the raw material and atmosphere as the oxidant is a newly developed method and its advantages are low production cost and the complex raw material can be treated by this method and its disadvantage is that the quality of sodium pyroantimonate is lower than that prepared by the oxidation method of hydrogen peroxide and the potash salt method.

Jan 1, 2006

By Akita Ito, Sumio Kato, Mikio Sugai, Shinichi Nakata

"Spark Plasma Sintering (SPS) is a newly developed method for the sintering of metal and ceramic powders, and completes their densification at low temperature and in short period. The SiC powder was synthesized from diatomite and graphite or carbon black by heating at 1 450°C for 1 hr in an argon atmosphere. The synthesized SiC powder was heated at 1500-1800°C, 50 MPa for 15-18 min by SPS. The relative density of sintered SiC body increased with the rise in the temperature. The oxidation of the surface of the SiC particle and impurities in SiC from diatomite greatly influenced the sintering promotion of SPS.IntroductionThe SiC has high hardness because of the covalent bonding, and is also excellent in thermal and chemical stability. However, it is difficult to obtain a dense SiC sintered body by the combustion heating-method. Therefore, the dense SiC bodies have been made by the use of additives and I or the hot pressing (HP) method.In this study, the SiC powder was synthesized by using diatomite of natural products and graphite, and carbon black of reagent as raw materials, and the relationship between the properties of SiC powders prepared at various synthetic conditions and the density of sintered body by SPS was examined."

Jan 1, 2000

By E. R. Vance, D. R. M. Brew

"Historically, Ordinary Portland cement has been the preferred medium to immobilise arsenic. However, arsenic in cement gives rise to calcium-arsenic phases and their known decomposition to calcium carbonate and arsenic trioxide via atmospheric carbonation raises serious questions about the long-term suitability of cement for arsenic immobilisation. Alternative matrices such as low-temperature ceramics (LTCs) potentially offer superior resistance towards carbonation owing to the absence of calcium. Consequently, the potential for arsenic immobilisation using LTCs has been investigated. Both AsIII and AsV have been incorporated and samples assessed according to a standard leaching protocol. AsIII persists in the porewater of alkali-bonded LTCs as sodium arsenite rendering them unsuitable for immobilisation. Thermal treatment of these LTCs to consolidate the microstructure and reduce open porosity resulted in sodium-rich cryptocrystalline matrices that leached arsenic and sodium readily. The omission of sodium in acid-bonded LTC formulations resulted in leach data that were close to the target value of 5 µg/ml in Toxicity Characterisation Leaching Protocol tests.IntroductionArsenic is a carcinogenic substance and its adverse effects of on humans, flora and fauna have been well documented [1-5]. As a consequence, many papers have been written on the prospective handling of arsenic-bearing waste. These can largely be divided into: (a) cleanup of arsenic-contaminated water using bacteria, precipitation, and/or UV irradiation to generate arsenic-rich sludges for subsequent immobilisation; (b) cleanup of arsenic-contaminated soil via chemical extraction for immobilisation of the As concentrate; and (c) immobilisation of industrial waste contaminated with As."

Jan 1, 2008

By A. F. Sidorov

A method of improving mineral recoveries from ores by modifying the physical and chemical properties of minerals using radioisotope radiation was tested. It was observed that irradiation modifies mineral cell sizes, changes the crystal structure of some minerals, reduces the sulfur content 1 to 1.5 % in sulfides, changes the zeta potential, alters the surface properties of mineral grains I and produces other changes. Preliminary tests indicate that accelerated electron treatment of ores in connection with mineral processing has a potential for improving mineral recoveries by flotation and by magnetic separations.

Jan 1, 1989

By Pradeep kumar Jha, Manas Mohan Mahapatra, Sabin Kumar Mishra, Satish Kumar Ajmani, Satish C. Sharma

"Due to mechanical/ electrical failure in the C.C. line or inadequate availability of molten steel from coming ladle, sometimes one/two outlets of a multi-strand tundish in continuous casting unit is closed. Closing any of the outlets affects the flow distribution inside the tundish which in turn governs the quality of steel coming out. Hence it is important to study which of the outlets should be closed to have proper results in terms of flow behavior and inclusion removal inside the tundish. Present study aims at finding the effect of closing one or two outlets on flow behavior and inclusion removal in a multi strand tundish. It was found that closing the near outlet (outlet near to the inlet) increases the inclusion removal tendency than closing the other two outlets in a six-strand billet caster tundish (only three outlets are considered because of symmetry).IntroductionContinuous casting process transforms molten metal into solid on a continuous basis. This process is the most efficient way to solidify large volumes of metal into simple shapes for subsequent processing [1]. Molten metal is tapped into the ladle from furnaces. From the ladle, the hot metal is transferred via a refractory shroud (pipe) to a holding bath called a tundish. The tundish allows a reservoir of metal to feed the casting machine while ladles are switched, thus acting as a buffer of hot metal as well as smoothing out flow, regulating metal feed to the moulds and cleaning the metal [2]."

Jan 1, 2012

By Tianyou Huang, Yuan Lu, Haimin Long, Jinwu Kang, Gang Nie

"The distortion of metal parts during heat treatment process is one of the main obstacles in industry to ensure high-quality work and less or no machining allowance, especially for large but thin steel castings such as heavy turbine blades. In the paper, a method is proposed to control the distortion by adjusting heat transfer coefficient of metal parts during heat treatment process. Required heat transfer coefficients can be realized by getting the metal parts into contact with various media such as water spray, insulation felt or materials with different heat conductivity. The control method based on this idea is set up and achieved. By using insulation felt and water spray to change the heat transfer coefficient during the stages of heat treatment process, the results indicate that the proper control time and vary with materials.IntroductionThe distortion of metal parts during heat treatment process is one of the main obstacles in industry to ensure high-quality work and to realize less or no machining allowance [1]. For example, the Three Gorges turbine blade’s distortion is as large as 50mm during heat treatment process. The uneven heating and cooling during heat treatment process is the main reason for distortion [2]. By adjusting heat transfer coefficient of different areas of metal parts, the heat treatment process could be controlled. The temperature variation, direct cause for distortion, could be under control. Loeser Klaus used high pressure gas to achieve uniform heat transfer during gas quenching and proposed the possibility to use ""Dynamic Quenching"" processes where the quenching severity is varied during quenching by stepwise control of either gas velocity or gas pressure [3]. Li Zhichao also suggested minimizing distortion by marking a component into several areas and imposing different heat transfer coefficients on each area [4]. Heat transfer coefficient can be controlled by getting the metal parts into contact with different media such as water spray, insulation felt, air or different heat conduction materials. In addition, the exact time to adjust the heat transfer coefficient is another factor for distortion. A method is presented in this paper by actively adjusting heat transfer coefficient for different areas of metal parts and different stages of heat treatment process to control their distortion. The corresponding experiments have been made by using different metal materials."

Jan 1, 2012

By Patrick F. Mahoney

Each year in the United States over 10 million tons of metal are discarded with our municipal waste. This, includes, not only ferrous metals, aluminum and copper but gold, silver, platinum and every other precious metal. Resource recovery, as an approach to waste management, is replacing disposal and it presents great opportunities for those in the metal refining and recovery industry. Combustion of waste enriches the metal fraction left in the ash to the point where metals can be efficiently recovered. The recovery and quality of metals can be enhanced by good combustion control. Innovative technology is needed to efficiently tap this generous, and renewable mine.

Jan 1, 1995

By C. A. Nogueira, F. Pedrosa, F. Margarido, R. N. G. Guerra

"A hydrometallurgical process for recycling spent Zn-MnO2 batteries was developed, involving leaching with sulfuric acid, purification by precipitation and metals separation for further recovery. Leaching of zinc oxide was easily attained while for manganese oxide was rather difficult depending on temperature and acid concentration. At 90°C and with the liquid/solid ratio of 20 L/kg, more than 95% of zinc is recovered in 30 minutes with 0.5M H2SO4. To attain similar recovery for manganese, higher levels of acid concentration and time are needed (e.g 0.7 M and 2 hours). After leaching a purification step is necessary to remove iron co-dissolved through Fe(III) precipitation. Separation of zinc from manganese by solvent extraction with 1M DEHPA follows in the process route. The countercurrent multistage separation diagram developed allows the production of a zinc electrolyte with 120 g/L Zn and 0.005 g/L Mn, and a raffinate with 16 g/L Mn and 0.013 g/L Zn.IntroductionThe recycling of spent Zn-MnO2 batteries is carried out by dedicated recyclers using several process alternatives [1]. Most of the running processes use pyrometallurgical technologies [2] based on zinc distillation. Alternative treatments by hydrometallurgy have been reported [3-5] but its application is scarce.In order to contribute to the development of alternative solutions, a process for recycling batteries based on Zn-MnO2 systems has been studied. The process is based on the hydrometallurgical treatment of spent batteries in sulfuric acid media (Figure 1). The process starts with the physical processing by shredding using cutting grinders, where the batteries are opened and size reduced, allowing the liberation of the interior electrode particles or pastes. The fines can be then separated and the coarse material containing the steel scrap can be treated to remove the remaining aggregate electrode. The final scrap also contains some plastics and other non-metal materials and can be further valorized."

Jan 1, 2008

By Yves Fautrelle, Kader Zaidat, Hervé Combeau, Miha Zaloznik, Mohammed M'Hamdi, Bachir Saadi, Xiaodong Wang, Knut Omdal Tveito

"Numerical simulations of macrosegregation formation during horizontal solidification of a hypoeutectic Sn-Pb alloy in a rectangular cavity is presented and compared to experimental results. The experiment involves a melting phase, a holding stage at constant temperature with/without application of electromagnetic stirring, and finally solidification. We simulate all stages of the experiment and study the segregation of Pb throughout the experiment. A twophase volume averaged model is used for the numerical simulations, accounting for thermosolutal convection and assuming perfect microscopic mixing (lever rule). The influence of the melting phase and the electromagnetic stirring is studied with different cases to illustrate the consequences on the flow pattern and Pb segregation. The numerical simulations are compared to the experimental data and the impact of chemical inhomogeneities prior to solidification on macrosegregation formation is discussed.IntroductionMany extensive investigations have been performed so far on the solidification of metallic alloys. However, the melting process of metallic alloy has not attracted attention in a same manner. Nevertheless, melting of alloy may put forth peculiar effects as described in the present paper. It has been observed from a benchmark experiment [1, 2] that significant stratification might arise during the melting process of Sn-Pb alloy. That effect was put forth thanks to the analysis of the experimental temperature distribution which indicated that the convective fluid flow was almost zero. The effect was enhanced when the lead composition was higher (above 6wt.%). The present paper is aimed at confirming that the melting of an alloy containing a heavier solute may be accompanied with a stratification of the solute which exerts a stabilizing effect on the convective fluid flow. Results obtained from numerical modeling are compared with experimental data obtained from the benchmark facility."

Jan 1, 2012

By G. P. Chaudhari, F. Warchomicka, M. Dikovits, V. Pancholi, C. Poletti

"The hot formability of a microalloyed steel with 0.16 wt-%C modified with N is studied by using processing maps. Compression tests of cylindrical samples are carried out using a Gleeble®3800 simulator in the range of temperature between 750 -1000°C and strain rates between 0.01-100 S-1. For this alloy, an Ar3-temperature about 740°C is determined by means of dilatometry. Processing maps are calculated using the modified dynamic material model developed by Murty and Rao for different logarithmic strains. For the instability map, the parameter Kj developed by the authors in previous works is used and compared with other instability values. Softening in the flow curves provoked by induced ferrite during deformation at low temperatures and low strain rates is reflected in the n-value. Light optical microscopy (LOM) and electron back scattered diffraction (EBSD) measurements are used to study the microstructure of the hot deformed samples to determine the deformation mechanisms active and to verify the processing maps.IntroductionProcessing maps offer a good possibility to optimize thermomechanical process parameters and to avoid defects in the products. Prasad et al. [1] developed the processing maps using the dynamic material model (DMM) and Murty & Rao [2] modified it. Processing maps consist of two superimposed maps: the dissipation efficiency and the instability map. The processing maps can be used to detect areas with a good hot formability, which are normally related to restoration of the material by dynamic recovery/recrystallization. For a high dissipation efficiency value and no instabilities, a good hot formability is predicted. In the DMM no storage of energy takes place and so the material is considered essentially dissipative, this is only true for high temperatures and high strain rates [1]."

Jan 1, 2012

By James Douglas

A century ago the AIME meeting of 1899 was held at the Palace Hotel in San Francisco California in September. For his presidential address, James Douglas presented this paper which is reprinted in full with the kind permission of the AIME. It presents an interesting comparison relating to events and circumstances in the metallurgical industries at the close of last century. Being on the eve of a new century ourselves, the Editors of this volume of the COPPER 99-COBRE 99 Proceedings considered this paper would be of general interest, hence it is included here. Douglas believed in effective interchange of technical experiences and ideas. He considered the extreme secrecy surrounding the copper works at Swansea, Wales, the world center of copper only years before the time his paper was delivered, as one key reason for its decline, (and eventual closure of all copper plants there). In his paper, the pace of developments in various sectors such as transportation (railroads, the dominant means of I transportation at the time), the iron and steel and copper industries were examined, in much the same way as one might do but on the high technology of today. James Douglas was born in Quebec City, Quebec, Canada and spent his early life there. Forced to move to the United States for family and financial reasons, he went on to become a pioneer in the new Arizona copper industry, and with luck and good judgement with his interest in the new mining properties he also became very wealthy. Douglas was an accomplished mining and metallurgical engineer. He was the first President of Phelps Dodge and helped transform the small trading company of Anson Phelps and William Dodge into a mining giant.

Jan 1, 1999

By T. Lezhava

Recycling technology of spent Mn-Zn system batteries has been worked out and tested in laboratory scale. The proposed technological scheme includes the following basic operations: breakage of batteries, hydro-vibrated treatment of broken up mass, electrolysis by using alkali electrolyte. This method enables extracting of 200-220 kg zinc in powder form, of 300-350 kg manganese concentrate and of 130 kg steel in the form of scrap per tone of broken up batteries.

Jan 1, 2006