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By Biswadeep Saha, Meenakshisundaram Ramanathan, Chai Ren, Sivaraman Guruswamy

"Fe-Ga alloys have a large low-field magnetostriction and these alloys are attractive candidates in energy conversion and harvesting applications. Small additions of W also increase the magnetostriction of Fe. In this paper changes in magnetostriction by W substitution for Ga in various Fe-x at.% Ga alloys are presented. Fe-Ga-W single crystals were grown using vertical Bridgman Growth technique. [001]-orientated single crystal samples were prepared with faces within 1 degree off <100> orientation. The samples were annealed at 1150 °C in the alpha-phase region and water quenched. The magnetostriction coefficient (3/2)A-100 measurements were made on these Fe-Ga-W single crystals. The result on the effects of W substitution and annealing on the magnetostrictive behavior of these alloys are discussed.*Support of this work by NSF-DMR under the award DMR-0854166 is gratefully acknowledged.IntroductionMagnetostrictive materials changes their dimension exhibit reversible strains and changes in elastic properties in the presence of an applied magnetic field or the reciprocal effect of changes in the magnetic properties with the application of stress [IJ and are very important in sensor, actuator device, linear motor, magnetomechanical devices, microelectro- mechanical devices, active vibration dampening devices application areas. The discovery of an order of magnitude enhancement in the magnetostriction of Fe with Ga addition coupled with low saturation magnetic fields, and excellent mechanical properties opened up the possibility of obtaining larger magnetostriction values in other low-cost ductile a-Fe phase based alloys with alloying additives that are less expensive than rareearths such as Tb and Dy [2·4l_ The magnetostriction values observed in Fe-Ga single crystals are sensitive to thermal history and composition. The formation of second short range ordering phases and local defects inside crystal structure can also cause a dramatic change to this alloy's magnetostriction behavior [5-9l_"

Jan 1, 2012

By Clyde S. Brooks

This paper undertakes to assess what opportunities exist for the economical recovery of non-ferrous metals from spent catalysts. The most promising recovery appears to lie with metals such as Co, Mo, Ni, W, heterogeneous catalysts used on a large scale in petroleum processing. Nickel is a metal with diverse applications on a large scale notably in hydrocarbon steam reforming and in vegetable oil hydrogenation. In addition, several of the precious metals, notably Pt, Pd, and Rh, find extensive use in fossil fuel processing and in automotive and power plant flue gas control. The hydrometallurgical and pyrometallurgical alternatives for processing are identified and discussed, especially with citations to illustrate reduction to commercial practice. Promising directions for adaptation of appropriate, economic separation technologies for recovery of non-ferrous catalytic metals generated in significant amounts for the secondary metal markets are identified. Recycling

Jan 1, 2000

By Celaletdin Ergun, Ibrahim Erden, Gurbuz Gunes, Thomas J. Webste, Huinan Liu, Abdurrahman Bahadll

"B, Ti, Ag, AI and Cu substituted hydroxyl apatites were synthesized via precipitation method. Then the samples were air-sintered at 1300°C for 2 hrs and characterized with XRD, SEM, FTIR, and cell adhesion behaviors.IntroductionSynthetic hydroxylapatite (HA, Ca10(P04)6(0H)2) has a similar composition and structure to biological apatite. Therefore, it has been safely and extensively used as an implant material for bone substitute. However, synthetic HA has been used for a various applications including medical or non-medical applications, such as matrices for drug release control, bone cements, tooth paste additive, blood purification agent, monolithic implants or coatings on metallic implants, packing media for column chromatography, gas sensors, catalysis and host materials for lasers and luminescent materials, etc. [1-9].The major factors affecting the performance of HA on these applications are crystal morphology, density, porosity, pore size and distribution, chemical composition, and surface structure. As provided by the high flexibility of the apatite structure a great variety of cationic and anionic species can be substituted into HA structure which is specifically considered as an effective method to modify the properties of HA [10,11]."

Jan 1, 2012

By Ray Y. Lin, Sunil G. Warrier

"Low cost processing of metal matrix composites is an essential requirement for this class of materials to be acceptable in commercial application. In an effort to reduce the cost of processing of metal matrix composites, an infrared pressureless liquid infiltration technique has been developed. The salient features of infrared infiltration are that it is rapid, simple and a low cost process. The rapid processing capability causes very little oxide formation on the alloy resulting in both improved wetting and flow characteristics and reduced oxygen contamination in the composite. Thus, vacuum is normally not required. Using infrared inflltration, aluminum and titanium matrix composites have been prepared under an ambient argon atmosphere. Reinforcements in these composites include carbon fibers, silicon carbide Nicalon fibers and Textron's SCS fibers. Microstructural and mechanical test results indicate that completely consolidated composites with good fiber distribution, limited interfacial reaction and high mechanical properties can be manufactured by this process. IntroductionAluminum and titanium matrix composites reinforced with ceramic reinforcements are strong candidates for numerous applications in the aerospace and automotive industries. Aluminum matrix composites are commonly fabricated by either solid state vacuum hot pressing, liquid state pressure infiltration or squeeze casting [1]. Although liquid state pressure infiltration and squeeze casting has significant advantages over solid state processes, the requirement for pressure makes these composites uneconomical for large scale industrial application. Titanium matrix composites are primarily fabricated by solid state diffusion bonding [2]. Pressureless liquid infiltration can significantly reduce the cost of fabrication in both the composite systems. However, during pressureless infiltration processes, several complications concerning the wetting characteristics and chemical compatibility arise."

Jan 1, 1994

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 D. L. Stewart

"Melt loss is usually one of the highest individual cost items in the operation of ah ingot casting facility. While melt loss and the resulting cost for the entire facility is usually well known (at least via standard cost accounting), dross generation and melt loss for individual unit operations within the plant are usually not known. Thus, the financial impact of various practices, alloys and scrap types is not known. Development of an accurate, relatively low-cost technique for measurement of melt loss at commercial scale would aid in understanding melt loss for existing units, as well as evaluation of the melt loss impact of alternate processes.This paper will describe a methodology developed at Alcoa for accurate and inexpensive measurement of melt loss at commercial scale. The methodology has been used to evaluate the impact of scrap type, melting practices, and dross treatment technology on melt loss."

Jan 1, 2000

"Recycling of solid wastes plays an important role in environmental protection. However, solid wastes are often contaminated with some undesired components so that many of these solid wastes are hardly economically recycled. Therefore, effective and efficient separation of undesired components from solid wastes becomes a crucial step for sustainable recycling of the solid wastes. There exist three general strategies of separation of undesired components from solid wastes: before-process separation, post-process separation and in-process separation. In this paper, different separation strategies are discussed in terms of energy requirement and availability, implementation complexity and additional need for environmental protection. It is concluded that of all separation strategies, in-process separation has the least energy requirement, the least implementation complexity and the minimum need for additional environmental protection.IntroductionIn industries, solid wastes almost come with every production process. Multi-million tons, if not billion tons, of solid wastes are being generated globally each year. These solid wastes are lowvalue materials in general, and often have very limited markets. As a matter of fact, many of these solid wastes have been stored on site or have been disposed of at landfills for many years, not only occupying lands, but also polluting environment. Therefore, effective and efficient recycling of solid wastes has been a very challengeable task and has played a very important role in environmental protection.One of the major barriers which hinder recycling of solid wastes is contamination of the solid wastes with some undesired components. These undesired components are components which are not wanted by production processes or applications where the solid wastes are consumed or recycled, since the undesired components often degrade qualities of the solid wastes, imposing negative effects on operations, facilities and product qualities of the production processes or applications. Sometimes, the undesired components may also pose severe environmental concerns. When undesired components are present in solid wastes at over-limit levels, the solid wastes tum to become destructive, useless and non-recyclable. Consequently, effective and efficient separation of undesired components from solid wastes becomes a crucial step for sustainable recycling of the solid wastes."

Jan 1, 2014

By Magdelinka Padenkova-Yaneva, Emilia Christova Kostakeva

"Environmental protection is becoming over the years an increasingly significant problem of mankind. Up to the last decade the only way to make the domestic waste harmless in Bulgaria was deposition on uncontrolled landfills without undertaking actions for protection of the soils. This also caused pollution to spread into the surface and underground waters and that is why actions are now undertaken for remediation of contaminated soils. This is achieved by developing projects for the closing down of polluted sites. In the present paper some projects for closing down of polluted areas are discussed. The actual conditions are examined and project decisions for preventing the surface waters from penetrating into the waste are presented. In this way the pollution of the soil is stopped and the soils are gradually remediate.IntroductionSoil is the topmost layer of the earth crust. It consists of mineral particles, organic substances, water, air and living organisms and is an extremely complex and changing living environment. Soil is a non-renewable natural resource which is of considerable importance in a number of crucial processes (production of foods, storing, filtrating and turnover of many substances, including water, carbon and nitrogen). It also serves as a basis for human activities, shaping the landscape, ground on which cultural heritage is built, and source of raw materials. These functions of soil must be protected both because of their social and economic significance and from the point of view of environmental protection.The processes of erosion, loss of organic substances, compaction, salination and contamination contribute to the degrading of soils accompanied by a negative impact on human health, natural ecosystems and changes in climate, as well as on the economy. All these make it necessary to protect soils from contamination. Over the last years intensive work started in Bulgaria for the construction of controlled sanitary landfills for rendering municipal solid waste harmless. Pursuant to Bulgarian legislation, in these controlled sanitary landfills measures are undertaken for protecting the soils from contamination through appropriate project decisions – the filtration of the products from the biological decomposition of waste into the adjacent sites (soils) and, therefore, the contamination of the surface and underground waters is prevented. At the same time the purity of air is maintained, human health is protected and conditions are created for including the controlled sanitary landfills into the surrounding landscape."

Jan 1, 2008

By Philippe Charlier

Recycling of aluminium contained in used aseptic beverage cartons is a difficult task which has nevertheless to be tackled by our modern societies. Techniques have earlier been developed by the paper and pulp industry for the recycling of the board fibres from collected post-consumer beverage cartons. A joint technical feasibility study by Granges and a leading beverage carton producer has dealt with different techniques for handling residues from repulping facilities. The aluminium obtained can be used as raw material for the production of thin gauge foil, thus closing the recycling loop.

Jan 1, 1995

By Yahui Feng, Zhiwen Wu, Chen Chen, Xin Hong

Large amounts of copper slag containing about 40 wt% iron is generated during the process of producing copper. Recovery of iron from the copper slag is very essential not only for recycling the valuable metals and mineral resources but also for protecting the environment. The purpose of this study was to investigate the possibility of separating fayalite by oxidation-reduction process into Magnetite and silicate phases in intermediate temperature condition. Experimental results show that when the oxidation reaction at 1000℃ for 120min and the oxygen flow is 0.1L/min, most fayalite decompose to hematite, less part of magnetite and silica. And then, the mixture of carbon and oxidation product is pressed into blocks and reduced to magnetite and silica at 900℃ for 90min. A magnetic product containing about 57.9wt% iron was obtained from the magnetic separation under a magnetic field strength of 100 mT.

Jan 1, 2015

By Magdelinka Padenkova-Yaneva, Emilia Christova Kostakeva

"One of the methods for waste treatment is composting during which as a result of controlled biological decomposition of organic waste in aerobic conditions harmless materials are received. Composting takes place in suitably designed premises which ensure the optimal conditions for biochemical decomposition of the waste. A usual way to process composting is the spreading of the waste on a base made from reinforced concrete.In the paper the phases and basic technical features of the process of composting, the requirements and properties of the base and the ways of protection of concrete base against corrosion are revealed. Technical decisions for a specific construction site in Bulgaria are shown and the advantage of achieving durability of the concrete constructions in the plant while achieving simultaneous environment protection from pollution is discussed.IntroductionComposting is the process of controlled biochemical decomposition of vegetable and animal organic waste in aerobic conditions as a result of which harmless materials are obtained. The latter have better stability and are rich in humus substances which are useful for agricultural crops and can be used for restoring the soil fertility [1, 2, 3, 4].In modern waste treatment plants a composting technology is adopted in which the waste is spread on a concrete base as piles with certain dimensions [1, 3]. These piles are periodically stirred or air is blown through them in order to ensure the quantity of oxygen required for the process of aerobic decomposition of the organic matter. The fluids and gases formed in the course of the composting are take away in order not to pollute the environment – air, water, and soils. For this purpose the base on which the waste is spread must satisfy certain requirements, and the gases must be taken away and rendered harmless in order to protect the atmospheric air from pollution. This paper discusses the need for protecting the concrete base from corrosion and characterizes the stages and main parameters of the composting process and the possibilities for primary and secondary protection of the concrete base from corrosion. Specific technical decisions applied in a composting facility in the area of the town of Plovdiv are presented."

Jan 1, 2008

By James R. Myers

A source of clean gas containing sulfur dioxide and sufficient oxygen for conversion to sulfur trioxide is essential to the production of sulfuric acid. SO2 containing gases obtained from roasting sulfide ores are heavily contaminated with inorganic dust and volatile impurities. If not removed, these contaminants will reduce product acid quality, foul the catalyst beds and mist eliminators, and accelerate equipment corrosion. This paper reviews conventional gas cleaning systems for metallurgical acid plants, followed by a discussion of modern systems utilizing DynaWave Scrubber technology. This technology is based on a unique approach togas scrubbing that can concurrently accomplish several gas cleaning/processing tasks. Scrubbing liquid is injected into the gas stream to create a "Froth Zone". This is a region of extreme turbulence, with a very high rate of liquid surface renewal. It efficiently removes both particulate matter and gas contaminants, and is also a cost effective quenching device for gases as hot as 1250 o C.

Jan 1, 1992

By Matthias Frommer, Carl-Peter Reipl, Reinhard Flende

"Today there is a growing demand for strip of superior steels with specifically tailored technological properties. Especially strips of high-strength, micro-alloyed steel grades applied to manufacture longitudinally and spiral-welded pipes are a growth market. Tubes are generally required to have high strength and sufficient toughness values and thus favour specific hot strip microstructures. The correlation of chemical analysis, process parameters and mechanical properties with microstructural features is still a challenging task. During the last decades, scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) have become useful tools for the characterization of complex microstructures. The EBSD data provides an immense variety of post-processing possibilities, e.g. related to grains, grain boundaries, misorientations or texture. This paper highlights the results of an advanced analysis of microstructures representing industrial produced hot-rolled strips and presents an approach to define and quantify some essential microstructural parameters.IntroductionHigh-strength microalloyed steels have been used for the production of welded pipes for more than 30 years. However, the alloy design of pipeline grades is being continuously modified and the process technology optimized because of the increasing high strength-toughness combination requirement for pipeline steels. Compact strip production (CSP®) technology is an upcoming promising route for the production of high-quality pipeline steel grades [1]."

Jan 1, 2012

By Mark W. Sajewycz

Creating technology, securing patent rights, and managing a patent portfolio are time-sensitive and dynamic activities. Agreements should be in place with technology partners (employees, contractors, joint venture partners), prior to embarking on research and development projects, so as to mitigate future disputes over patent rights. Technology partners should be educated on patent law basics so as to be mindful of patent bar triggering events. Accurate records must be maintained to capture information relevant for preparation and filing of patent application, including subject matter, names of inventors, and invention date. Developed inventions should be evaluated for whether to file for patent protection, delay patenting until technology is further developed, maintain trade secrecy, or effect deliberate public disclosure. Once decision is made to file for patent protection, time is of the essence, and application for patent protection should be filed as soon as possible, as many countries award patents on a "first-to file" basis. Decisions on where to file are made having regard to potential competitive advantages versus cost considerations, and can be delayed by taking advantage of priority rights recognized in patent legislation of most countries. Once patents are granted, competitors must be policed for potential patent infringement, and legal action may be necessary to prevent patent infringement.

Jan 1, 2006

By M. Patel, A. W. Piper, R. A. Forsdick

"Lead bullion is refined in kettles to remove the contained impurities such as copper, antimony, silver and bismuth. These impurities are removed sequentially by the addition of one, or more, reagents to the bath. Impurity elements react selectively with the reagents to form a dross layer on the surface that is subsequently removed for further processing. Mixing the lead bath using specific impeller designs, which form a vortex to ensure that good contact takes place, carries out the reactions. It is important that the mixing is controlled to achieve the optimum bath conditions and hence good dross grades.This paper presents initial modelling work on the kettle refining process using both physical modelling (Water Models) and mathematical modelling (Computational Fluid Dynamics - CFD). Comparisons between measured plant data and simulation results are given.IntroductionThe refining of lead bullion takes place in hemispherical kettles of varying sizes. It is normal practice to remove the impurity elements sequentially, by the addition of reagents, which selectively react with the impurity element. The impurity element forms a dross layer on the surface, which can be removed for subsequent processing at the end of the reaction period.All the refining stages in the production of lead and lead alloys involve mixing the lead bath, although different conditions are required for each stage. At Britannia Refined Metals mixing is achieved using either 3 or 4 angled or flat blade impellers, which generate a vortex in the central region of the kettle. However, throughout the industry a wide range of mixer types are used which are all trying to achieve the same result."

Jan 1, 1999

By Seung-Chul Lee

Transparent conducting tin(1V) oxide thin films have been studies and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process condition and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.18-cm and the transmittance is higher than 90% in a visible range.

Jan 1, 1999

By Simon Lekakh

Direct reduction of Cu,Ni,W,VandMo oxides from various industrial wastes the melting of iron and steel in different furnaces was studied by thermodynamic computation and experimental methods. Thermodynamics was used to compute the final partition of the alloying additions between iron-carbon melts and oxides contained in the slag. It was shown that the sequence of the reduction reactions depended on the melt composition as well as temperature. Kinetic factors limited recovery in induction melting, while experimentally measured final partition coefficients were close to equilibrium during EAF melting. The possibility of the partial substitution of expensive ferroalloys, by different industrial wastes containing nonferrous oxides, was evaluated in foundry and mini-mill conditions.

Jan 1, 2006

By Natasa Mitevska

The distribution coefficients of Ag, As, Au, Bi, Co, Cu, Ni, Pb, Sb, Se, Te, and Zn between copper matte and slag from the reverb furnace No.2 at the Copper Smelter and Refinery, RTB BOR (Yugoslavia), are presented in this paper. The influence of the matte grade on the minor elements distribution coefficients between copper matte and slag is analyzed. The minor elements distribution in the slag phase along the slag melt depth and the furnace length is also determined.

Jan 1, 2002

By A. A. Shook

The off gas from the #5 converter at BHP Copper&apos;s San Manuel smelter was analyzed continuously over a period of several weeks using an online sulfur dioxide analyzer. These data have shown that the oxygen utilization efficiency of this copper converter was somewhat lower than anticipated, and that oxygen efficiency declines significantly during the copper blow. A sharp reduction in sulfur dioxide generation was consistently observed at the end of the copper blow, which could be used by converter operators to prevent over-blowing and minimize rolling out of stack.

Jan 1, 1999

By Melissa L. Trapani

The removal of molten products from metallurgical furnaces is one of the most hazardous and labour intensive processes in a non-ferrous smelter. The proximity of operators to the molten metal and slag during tapping and the oxygen lancing that facilitates the flow have led to many reported injuries on tapping floors. In most cases, tapholes are opened and closed periodically leading to extreme thermal cycling in the tapping assembly. As a consequence, refractory wear rates are high and unpredictable in the taphole. This paper provides a review of the current state of taphole development, and gives a methodology that is now being applied to gain a better understanding of the taphole region to allow design improvements.

Jan 1, 2002