WorldWideScience

Sample records for metallurgically important metals

  1. Comparative assessment of metallurgical recovery of metals from electronic waste with special emphasis on bioleaching.

    Science.gov (United States)

    Priya, Anshu; Hait, Subrata

    2017-03-01

    Waste electrical and electronic equipment (WEEE) or electronic waste (e-waste) is one of the fastest growing waste streams in the urban environment worldwide. The core component of printed circuit board (PCB) in e-waste contains a complex array of metals in rich quantity, some of which are toxic to the environment and all of which are valuable resources. Therefore, the recycling of e-waste is an important aspect not only from the point of waste treatment but also from the recovery of metals for economic growth. Conventional approaches for recovery of metals from e-waste, viz. pyrometallurgical and hydrometallurgical techniques, are rapid and efficient, but cause secondary pollution and economically unviable. Limitations of the conventional techniques have led to a shift towards biometallurgical technique involving microbiological leaching of metals from e-waste in eco-friendly manner. However, optimization of certain biotic and abiotic factors such as microbial species, pH, temperature, nutrients, and aeration rate affect the bioleaching process and can lead to profitable recovery of metals from e-waste. The present review provides a comprehensive assessment on the metallurgical techniques for recovery of metals from e-waste with special emphasis on bioleaching process and the associated factors.

  2. Metallurgical Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to increase basic knowledge of metallurgical processing for controlling the microstructure and mechanical properties of metallic aerospace alloys and...

  3. A multi-level code for metallurgical effects in metal-forming processes

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, P.A.; Silling, S.A. [Sandia National Labs., Albuquerque, NM (United States). Computational Physics and Mechanics Dept.; Hughes, D.A.; Bammann, D.J.; Chiesa, M.L. [Sandia National Labs., Livermore, CA (United States)

    1997-08-01

    The authors present the final report on a Laboratory-Directed Research and Development (LDRD) project, A Multi-level Code for Metallurgical Effects in metal-Forming Processes, performed during the fiscal years 1995 and 1996. The project focused on the development of new modeling capabilities for simulating forging and extrusion processes that typically display phenomenology occurring on two different length scales. In support of model fitting and code validation, ring compression and extrusion experiments were performed on 304L stainless steel, a material of interest in DOE nuclear weapons applications.

  4. Mechanical and metallurgical properties of dissimilar metal joints using novel joining techniques

    Science.gov (United States)

    Ashcroft, Emma Jane

    In recent years there have been significant new developments in welding processes for joining stainless steel and dissimilar metals. This is associated with the rise in interest of using stainless steel in the automotive industry from both car manufacturers and stainless steel producers. The main reason for using stainless steel within the automotive industry is the combination of formability and high strength but also the improved corrosion resistance when compared to zinc coated mild steel. This research explores the mechanical and metallurgical properties of dissimilar metal joining and determines a relationship between the fatigue properties and weld geometry. The research focuses on the relatively unexplored joining techniques of Laser Hybrid Welding and Cold Metal Transfer applied to joining stainless steel grades Hy-Tens 1000 and LDX 2101 to Dogal 260RP-X mild steel. The joints are assessed in terms of tensile, fatigue and metallurgical properties. Experimental results and analysis show that the fatigue properties of both laser hybrid welding and cold metal transfer joints are a linear relationship with a negative gradient to value of the root angle on the mild steel side of the joints, as the angle at the root decreases the fatigue life increases.It was found that when joining the material combinations outlined in this research with Laser Hybrid Welding the resulting solidified weld pool was chemically inhomogeneous. However, welds produced using Cold Metal Transfer resulted in a chemically homogenous weld pool and consistent microhardness. Comparisons with laser welding show that laser hybrid welding and cold metal transfer can produce joints with mechanical properties comparable to welding methods currently being used in the automotive industry, for example, laser welding.

  5. Powder metallurgical high performance materials. Proceedings. Volume 1: high performance P/M metals

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of this sequence of seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

  6. Effects of different production technologies on mechanical and metallurgical properties of precious metal denture alloys

    Science.gov (United States)

    Ferro, Paolo; Battaglia, Eleonora; Capuzzi, Stefano; Berto, Filippo

    2017-12-01

    Precious metal alloys can be supplied in traditional plate form or innovative drop form with high degree of purity. The aim of the present work is to evaluate the influence of precious metal alloy form on metallurgical and mechanical properties of the final dental products with particular reference to metal-ceramic bond strength and casting defects. A widely used alloy for denture was selected; its nominal composition was close to 55 wt% Pd - 34 wt% Ag - 6 wt% In - 3 wt% Sn. Specimens were produced starting from the alloy in both plate and drop forms. A specific test method was developed to obtain results that could be representative of the real conditions of use. In order to achieve further information about the adhesion behaviour and resistance, the fracture surfaces of the samples were observed using `Scanning Electron Microscopy (SEM)'. Moreover, material defects caused by the moulding process were studied. The form of the alloy before casting does not significantly influence the shear bond strength between the metal and the ceramic material (p-value=0,976); however, according to SEM images, products from drop form alloy show less solidification defects compared to products obtained with plate form alloy. This was attributed to the absence of polluting additives used in the production of drop form alloy. This study shows that the use of precious metal denture alloys supplied in drop form does not affect the metal-ceramic bond strength compared to alloys supplied in the traditional plate form. However, compared to the plate form, the drop form is found free of solidification defects, less expensive to produce and characterized by minor environmental impacts.

  7. Treatment of metallurgical wastes : recovery of metal values from smelter slags by pressure oxidative leaching

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.; Perederiy, I.; Papangelakis, V.G. [Toronto Univ., ON (Canada). Dept. of Chemical Engineering and Applied Chemistry

    2008-07-01

    Vast quantities of slag are produced and dumped as waste by-products during the production of base metals by smelting operations. These slags contain large amounts of valuable metals which lead to a decrease in metal yield and, combined with the entrapped sulphur, pose a danger to the environment. The dissolution of fayalite is important for the selective recovery of valuable metals and the cleanup of slags in high pressure oxidative leaching. The nature of base metals and iron in solidified slag must be investigated in order to understand the mechanism of the process. This paper discussed the application of powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) for the characterization of a smelter slag microstructure. The study used leaching tests with the same smelter slag to measure and monitor the results of leaching, including metal extraction levels, the extent of iron dissolution as well as impurity contents. The paper provided information on the experiment with particular reference to slag leaching, chemical analysis, and characterization. It was concluded that slag consists of several solid phases with base metal sulfide and oxide droplets entrapped in the fayalite matrix or silica regions. Therefore, nickel, copper, cobalt, and zinc need to be exposed either chemically or mechanically to promote their recovery. 21 refs., 4 tabs., 5 figs.

  8. Metallurgical coating system

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, L.C.; Whittaker, G.S.

    1984-05-01

    The present invention relates to a novel metallurgical coating system which provides corrosion resistance and non-stick properties to metallic components which are subjected to unusually severe operating conditions. The coating system comprises a first layer comprising tantalum which is deposited upon a substrate and a second layer comprising molybdenum disilicide which is deposited upon the first layer.

  9. Metallurgical reactions in the coalescence zone between a reinforcement and a base metal in reinforced brazed joints

    Directory of Open Access Journals (Sweden)

    Zorc, B.

    2004-12-01

    Full Text Available A reinforcement wire added to a brazed joint strongly improves the properties of the joint, i.e., its strength, toughness and resistance to crack initiation and propagation. This effect, however, can be achieved only if the reinforcement wire is of a suitable shape, from an appropriate material as regards the base metal and the brazing alloy and it coalesces strongly and toughly with the base metal. The properties of such a joint depend on the reinforcement wire and not on the brazing alloy. The most favourable reinforcement shape was determined. Metallurgical reactions among the base metal, the brazing alloy, and the reinforcement were studied.

    La armadura, añadida a las uniones fuertemente soldadas, mejora considerablemente las características de la unión, es decir, su dureza, tenacidad y resistencia frente a la formación y propagación de la grieta separada. Se puede alcanzar dicho resultado solamente si el alambre de la armadura tiene la forma apropiada, está formado con el material adecuado (acorde al material de base y la unión y se funde de manera fuerte y tenaz con el material de base. Las propiedades de la unión mencionada, dependen del alambre de la armadura y no de la soldadura. Se determina la forma más ventajosa de la armadura y se investigan las reacciones metalúrgicas entre el material de base, la soldadura y la armadura.

  10. A two-step leaching method designed based on chemical fraction distribution of the heavy metals for selective leaching of Cd, Zn, Cu, and Pb from metallurgical sludge.

    Science.gov (United States)

    Wang, Fen; Yu, Junxia; Xiong, Wanli; Xu, Yuanlai; Chi, Ru-An

    2018-01-01

    For selective leaching and highly effective recovery of heavy metals from a metallurgical sludge, a two-step leaching method was designed based on the distribution analysis of the chemical fractions of the loaded heavy metal. Hydrochloric acid (HCl) was used as a leaching agent in the first step to leach the relatively labile heavy metals and then ethylenediamine tetraacetic acid (EDTA) was applied to leach the residual metals according to their different fractional distribution. Using the two-step leaching method, 82.89% of Cd, 55.73% of Zn, 10.85% of Cu, and 0.25% of Pb were leached in the first step by 0.7 M HCl at a contact time of 240 min, and the leaching efficiencies for Cd, Zn, Cu, and Pb were elevated up to 99.76, 91.41, 71.85, and 94.06%, by subsequent treatment with 0.2 M EDTA at 480 min, respectively. Furthermore, HCl leaching induced fractional redistribution, which might increase the mobility of the remaining metals and then facilitate the following metal removal by EDTA. The facilitation was further confirmed by the comparison to the one-step leaching method with single HCl or single EDTA, respectively. These results suggested that the designed two-step leaching method by HCl and EDTA could be used for selective leaching and effective recovery of heavy metals from the metallurgical sludge or heavy metal-contaminated solid media.

  11. Electromagnetic equipment for non-contacting treatment of liquid metal in metallurgical processes

    Science.gov (United States)

    Lehman, A.; Sjoden, O.; Kuchaev, A.

    2006-09-01

    Electromagnetic stirring improves metal quality, productivity and reduces costs in con­ tinuous casting. For each application, the optimum stirrer choice can be made taking into account the steel grade cast, the strand sizes, casting speed, reduction ratio, tem­ perature. Electromagnetic braking reduces the rate of metal flow in a mould, which in turn reduces breakouts and cracks, as well as surface and subsurface defects in slab cast­ ing. Electromagnetic stirring in ladle furnaces gives an improved chemical and thermal homogenisation, increased productivity and a superior steel cleanliness. Figs 10, Refs 6.

  12. Biological recovery of metals, sulfur and water in the mining and metallurgical industry

    NARCIS (Netherlands)

    Weijma, J.; Copini, C.F.M.; Buisman, C.J.N.; Schultz, C.E.

    2002-01-01

    Metals of particular interest in acid mine drainage and industrial wastewaters include copper, zinc, cadmium, arsenic, manganese, aluminum, lead, nickel, silver, mercury, chromium, uranium and iron, in a concentration that can range from 106 to 102 g/l. The composition of such wastewater reflects

  13. Analysis on environmental impact of radiation from metallurgical project for rare metals

    International Nuclear Information System (INIS)

    Xia Zitong; Zhang Baozeng

    2012-01-01

    Rare metals are the composition of many high-property metal materials, which has a wide range of uses in the field of national defense advanced science technology. Since Ta-Nb material is associated radioactive mineral resources, and it contains high radionuclide, resulting in some radioactive indicators in process and workplace of the Ta-Nb smelting projects were significantly higher than that of the surrounding environmental radiation background. Based on the analysis of Ta-Nb smelting projects, the major sources of pollution were identified. and the possible radiation impact of the project was analyzed and evaluated, corrective measures on the process layout were also proposed, and reasonable suggestions of how to optimize the radiation protection were made. (authors)

  14. Deep cleaning of a metallurgical zinc leaching residue and recovery of valuable metals

    Science.gov (United States)

    Xing, Peng; Ma, Bao-zhong; Zeng, Peng; Wang, Cheng-yan; Wang, Ling; Zhang, Yong-lu; Chen, Yong-qiang; Wang, Shuo; Wang, Qiu-yin

    2017-11-01

    Huge quantities of zinc leaching residues (ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals (mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages: acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L-1, a liquid/solid ratio of 4:1 (mL/g), a leaching time of 2 h, and a temperature of 90°C. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L-1, a pH value of 1.0, a leaching time of 1 h, and a temperature of 30°C. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.

  15. New radionuclide specific laboratory detection system for metallurgical industry

    International Nuclear Information System (INIS)

    Burianova, L.; Solc, J.; Dryak, P.; Moser, H.; Branger, T.; Garcia-Torano, E.; Peyres, V.; Capogni, M.; Luca, A.; Vodenik, B.; Oliveira, C.; Portugal, L.; Tzika, F.; Lutter, G.; Szucs, L.; Dziel, T.; Burda, O.; Dirk, A.; Martinkovic, J.; Sliskonen, T.; Mattila, A.

    2014-01-01

    One of the main outputs of the European Metrology Research Programme (EMRP) project 'Ionising radiation metrology for the metallurgical industry' (MetroMetal) was the recommendation on a novel spectrometric detection system optimized for the measurement of radioactivity in metallurgical samples. The recommended system, prototypes of which were constructed at two project partner's laboratories, was characterized by using Monte Carlo (MC) simulations. Six different MC codes were used to model the system and a range of cylindrical samples of cast steel, slag and fume dust. The samples' shape, density, and elemental composition were the same as the ones of the calibration standards developed within the project to provide traceability to end-users. The MC models were used to calculate full-energy peak and total detection efficiencies as well as true coincidence summing correction (TCSC) factors for selected radionuclides of interest in the metallurgical industry: 60 Co, 137 Cs, 192 Ir, 214 Bi, 214 Pb, and 208 Tl. The MC codes were compared to each other on the basis of the calculated detection efficiencies and TCSC factors. In addition, a 'Procedural guide for calculation of TCSC factors for samples in metallurgical industry' was developed for end-users. The TCSC factors reached in certain cases up to 32% showing that the summing effects are of high importance in the close measurement geometries met in routine analysis of metallurgical samples. (authors)

  16. Metallurgical plasma torches

    International Nuclear Information System (INIS)

    Shapovalov, V.A.; Latash, Yu.V.

    2000-01-01

    The technological equipment for the plasma heating of metals, plasma melting and plasma treatment of the surface is usually developed on the basis of are plasma torches using direct or alternating current. The reasons which partly restrict the industrial application of the plasma torches are the relatively short service life of the electrode (cathode) on which the arc is supported, and the contamination of the treated metal with the products of failure of the electrode. The aim of this work was to determine the reasons for the occurrence of negative phenomena observed in the process of service of plasma torches, and propose suitable approaches to the design of metallurgical plasma torches characterised by a long service life

  17. 7th european metallurgical conference EMC 2013

    Directory of Open Access Journals (Sweden)

    Srećko R. Stopić

    2014-02-01

    Full Text Available From June 23 – 26, 2013, the GDMB Society for Mining, Metallurgy, Resource and Environmental Technology organized 7th European Metallurgical Conference (EMC 2013 in Weimar, Germany. The previous European metallurgical conferences were organized by  the GDMB in Friedrichshafen (2001, Hanover (2003, Leipzig (2005, Duesseldorf (2007, Innsbruck (2009, and Duesseldorf (2011. The GDMB is a non-profit organization from Clausthal, Germany,,focused on combining science with practical experience in metallurgy, mining, materials engineering, mineral processing, recycling and refining of metals, and  manufacturing of semi- and finishing products. The European Metallurgical conference EMC is one of the most well-known conferences worldwide in the field of non-ferrous metallurgy and is attended regularly by decision makers from industry and universities. The scientific program contained 6 plenary lectures and more than 130 presentations. An extensive poster exhibition was held, during which the authors had an opportunity to introduce their posters to the entire plenum as a part of a brief presentation., The € 500 worth “Poster Award EMC 2011 was awarded to Christoph Pichler from the Montan-University in Leoben, Austria. Not only the most important European countries were represented here, but also more than one third of the lecturers were from countries outside Europe (Canada, Japan, China, USA, South Africa, Australia. The origin of the participants reflects the aim of the organizers: to make this conference a worldwide platform for the scientific exchange of experience and information. The scientific presentations of the conference are presented in Proceedings: Vol. 1: Copper, Precious Metals, Waste effluents Treatment/ Biohydrometallurgical applications; Process Metallurgy, Bridging Non-Ferrous and Ferrous Metallurgy; Vol. 2: Lead and Zinc, Light metals, Sustainable technologies, Sustainable of non-ferrous metals production, Process Control

  18. Fate of metal-associated POM in a soil under arable land use contaminated by metallurgical fallout in northern France

    NARCIS (Netherlands)

    Labanowski, J.; Sebastia, J.; Foy, E.; Jongmans, T.; Lamy, I.; Oort, van F.

    2007-01-01

    Organic matter is a major metal-retaining constituent in soils. Among the diversity of organic components in soils, particulate organic matter (POM) accumulates large amounts of metals, but the fate of such metal-associated POM is unknown. We studied different POM size fractions and their

  19. Thallium isotopes in metallurgical wastes/contaminated soils: A novel tool to trace metal source and behavior.

    Science.gov (United States)

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin; Ettler, Vojtěch; Trubač, Jakub; Chrastný, Vladislav; Penížek, Vít; Teper, Leslaw; Cabala, Jerzy; Voegelin, Andreas; Zádorová, Tereza; Oborná, Vendula; Drábek, Ondřej; Holubík, Ondřej; Houška, Jakub; Pavlů, Lenka; Ash, Christopher

    2018-02-05

    Thallium (Tl) concentration and isotope data have been recorded for contaminated soils and a set of industrial wastes that were produced within different stages of Zn ore mining and metallurgical processing of Zn-rich materials. Despite large differences in Tl levels of the waste materials (1-500mgkg -1 ), generally small changes in ε 205 Tl values have been observed. However, isotopically lighter Tl was recorded in fly ash (ε 205 Tl∼-4.1) than in slag (ε 205 Tl∼-3.3), implying partial isotope fractionation during material processing. Thallium isotope compositions in the studied soils reflected the Tl contamination (ε 205 Tl∼-3.8), despite the fact that the major pollution period ended more than 30 years ago. Therefore, we assume that former industrial Tl inputs into soils, if significant, can potentially be traced using the isotope tracing method. We also suggest that the isotope redistributions occurred in some soil (subsurface) horizons, with Tl being isotopically heavier than the pollution source, due to specific sorption and/or precipitation processes, which complicates the discrimination of primary Tl. Thallium isotope analysis proved to be a promising tool to aid our understanding of Tl behavior within the smelting process, as well as its post-depositional dynamics in the environmental systems (soils). Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Prevalencia de los factores de riesgo cardiovascular en trabajadores de una planta metalúrgica Prevalence of cardiovascular risk factors among workers in a metallurgical factory

    Directory of Open Access Journals (Sweden)

    Juan Antonio Alonso Díaz

    2012-09-01

    and sex obtained by applying a standardized protocol performed during periodic medical examinations at work to a group of 358 workers, 330 men and 28 women, in a metallurgical industry in Cantabria with a mean age of 42 ± 8 years. Result: Dyslipidemia is the most important risk factor for its high prevalence (52% in a relatively young population, followed by smoking (35% and obesity (22%. These three risk factors are also those with a higher attributable risk in the incidence of ischemic heart disease in the general Spanish population, so they should be subject to intervention. Conclusions: Occupational Health Service companies have a privileged position due to their accessibility to evaluate and treat cardiovascular risk factors present in the working population they serve.

  1. Radiation protection aspects in importing metallic scraps

    International Nuclear Information System (INIS)

    Risica, S.; Di Ciaccio, P.

    1996-09-01

    The meeting deals with radiation protection problems caused by the possibility that radioactive metal scraps or radioactive sources hidden in the scraps, may arrive in a foundry. The importance of this issue and of rational and systematic solutions is showed by several accidents, happened in the past in numerous countries, by many signals in Italy and by some papers published in international scientific journals or reports issued by authorities and institutions in different countries

  2. Natural arsenic attenuation via metal arsenate precipitation in soils contaminated with metallurgical wastes: III. Adsorption versus precipitation in clean As(V)/goethite/Pb(II)/carbonate systems

    International Nuclear Information System (INIS)

    Vaca-Escobar, Katherine; Villalobos, Mario; Ceniceros-Gómez, Agueda E.

    2012-01-01

    Soil contamination with As and potentially harmful metals is a widespread problem around the world especially from mining and metallurgical wastes, which release substantial amounts of these elements to the environment in potentially mobile species. Recently, it has been found that in various Mexican soils contaminated with these types of wastes, arsenate is not in the form of sorbed species on Fe oxides present in the soils, as generally reported in the literature, but in the form of very insoluble compounds such as Pb, Cu and Ca arsenates. Here a thermodynamic model is applied and validated with the results from wet chemical experiments to determine the fundamental geochemical conditions governing the mobility of As in the presence of Pb. For this purpose, a relatively simple but fundamental system of goethite (α-FeOOH)/As(V)/Pb(II)/carbonate was defined as a function of the As(V)/Fe(III) ratio, in a pH range of 5–10. The speciation model included the simultaneous inclusion of triple layer surface complexation and arsenate precipitation equilibria. The model predicts that from very low total As(V)/Fe(III) molar ratios (0.012 at pH 7) the precipitation mechanism significantly influences the attenuation of As(V), and rapidly becomes the dominant process over the adsorption mechanism. Model results identify the quantitative conditions of predominance for each mechanism and describe the transition conditions in which relatively large fractions of adsorbed, precipitated and dissolved As(V) species prevail. Experimental measurements at selected As(V)/Fe(III) ratios and pH confirmed the predictions and validated the coupled thermodynamic model utilized.

  3. Perda auditiva induzida pelo ruído em trabalhadores de metalúrgica Noise induced hearing loss in metallurgical workers

    Directory of Open Access Journals (Sweden)

    Simone Adad Araújo

    Full Text Available Introdução: A perda auditiva induzida pelo ruído é uma patologia insidiosa cumulativa, que cresce ao longo dos anos de exposição ao ruído associado ao ambiente de trabalho. Objetivos: Identificar e quantificar a ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e os principais sintomas otorrinolaringológicos referidos pelos trabalhadores. Forma de estudo: prospectivo clínico randomizado. Casuística e métodos: Pesquisa realizada no período de janeiro a março de 2000 com 187 trabalhadores de indústria metalúrgica no município de Goiânia, avaliados por médicos otorrinolaringologistas através de roteiro de entrevista e audiometria ocupacional. Resultados: Foram obtidas audiometrias ocupacionais sendo: 21% sugestivas de PAIR, 72%, normais e 7%, sugestivas de outras doenças auditivas. Os sintomas auditivos mais freqüentes foram: dificuldade de compreensão da fala, 12%; hipoacusia, 7%; tinitus, 13%; sensação de plenitude auricular, 4%; otorreia, 6%; tonturas, 12%. Conclusão: Concluímos que em metalúrgica há ocorrência de alterações auditivas sugestivas de Perda Auditiva Induzida pelo Ruído e queixa de sintomas otorrinolaringológicos significativos.Introduction: Noise induced hearing loss is a cumulative pathological disease that increases over the years with exposure to noise associated with the work atmosphere. Objectives: To identify and quantify the occurrence of hearing loss suggestive of Noise Induced Hearing Loss (NIHL and the principle otolaryngological symptoms referred to by workers. Study design: prospective clinical randomized. Material and method: Research was carried out from January to March of 2000 with 187 metallurgical workers in the city of Goiânia, who were evaluated by otolaryngologists by means of a combination of interviews and occupational hearing exams. Results: Occupational hearing tests results were: 21% suggestive of NIHL, 72% normal, and 7% suggestive of

  4. The 6th European metallurgical conference EMC 2011: Proceedings review

    Directory of Open Access Journals (Sweden)

    Srećko R. Stopić

    2011-10-01

    Full Text Available The GDMB Society for Mining, Metallurgy, Resource and Environmental Technology organized the 6th European Metallurgical Conference (2011 in Duesseldorf from June 26 to 29, 2011. The same venue hosted the most important international metallurgical trade fairs for metallurgy of iron and steel, new casting and thermochemical processes METEC, GIFA, THERMOPROCESS and NEWCAST. The previous European metallurgical conferences were organized by GDMB in Friedrichshafen (2001, Hanover (2003, Leipzig (2005, Duesseldorf (2007, Innsbruck (2009. The GDMB is a non-profit organization situated in Clausthal in Germany, which is related to combining science with the practical experience in metallurgy, mining, materials engineering, mineral processing, recycling and refining of metals, and manufacturing of semi- and finishing products. The European Metallurgical conference EMC is one of the most known conferences worldwide in the field of non-ferrous metallurgy and is attended regularly by the decision makers from the industry and universities. The scientific program contained 6 plenary lectures and more than 160 presentations from 40 countries in 5 parallel series. An extensive poster exhibition was held, during which the authors had an opportunity to introduce their posters to the entire plenum as a part of a brief presentation. The best poster from the Montan-University in Leoben, Austria, was awarded the € 500 'Poster Award EMC 2011'. Not only were the most important European countries represented here, more than one third of the lecturers were from the non-European countries (Canada, Japan, China, USA, South Africa, Australia. The origin of the participants reflects the aim of the organizers: to make this conference a worldwide platform for the scientific exchange of experience and information. More than 400 participants from all over the world participated at this conference. The scientific presentations of the conference are presented in five Proceedings

  5. Diagnosis of employee engagement in metallurgical enterprise

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2013-01-01

    Full Text Available In the theoretical part of the publication an overview of the definitions of employee engagement was conducted together with the analysis of the methods and techniques which influence the professional activity of the employees in the metallurgical enterprise. The practical part discusses the results of diagnosis of engagement in steelworks. Presented theories, as well as the research, fill the information gap concerning the engagement of the employees in metallurgical enterprises. This notion is important due to the fact that modern conditions of human resources management require the engagement of the employees as something commonly accepted and a designation of manufacturing enterprises.

  6. Production of iron from metallurgical waste

    Science.gov (United States)

    Hendrickson, David W; Iwasaki, Iwao

    2013-09-17

    A method of recovering metallic iron from iron-bearing metallurgical waste in steelmaking comprising steps of providing an iron-bearing metallurgical waste containing more than 55% by weight FeO and FeO equivalent and a particle size of at least 80% less than 10 mesh, mixing the iron-bearing metallurgical waste with a carbonaceous material to form a reducible mixture where the carbonaceous material is between 80 and 110% of the stoichiometric amount needed to reduce the iron-bearing waste to metallic iron, and as needed additions to provide a silica content between 0.8 and 8% by weight and a ratio of CaO/SiO.sub.2 between 1.4 and 1.8, forming agglomerates of the reducible mixture over a hearth material layer to protect the hearth, heating the agglomerates to a higher temperature above the melting point of iron to form nodules of metallic iron and slag material from the agglomerates by melting.

  7. Evaluation of solubility in simulated lung fluid of metals present in the sludge from a metallurgical industry to produce metallic zinc

    International Nuclear Information System (INIS)

    Lima, Rosilda Maria Gomes de

    2012-01-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) metal particles present in a pile of sludge accumulated under exposure to weathering from the Cia Mercantil Inga, located at the Ilha da Madeira, Sepetiba Bay, Rio de Janeiro. Plant samples collected in the neighboring of the pile and bioindicators placed in the region and collected after some months indicated that the inhabitants of Ilha da Madeira have been exposed to trace elements such zinc, cadmium, mercury and lead, produced during the processing of zinc minerals (hemimorphite - Zn 4 (OH) 2 Si 2 O 7 .H 2 O, and willemite - Zn 2 SiO 4 ). A static dissolution test in vitro was used to determine the solubility parameters using a simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the sludge samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the sludge. The solubility parameters obtained for Zn, Cd, Cr, Ni and Mn present in the rapid dissolution fraction in SLF were 0.945; 0.473; 0.226; 0.300 and 0.497, respectively, and the corresponding times for half life of dissolution of the rapid fraction were f r = 2.082 days; f r = 0.09 days; f r = 0.37 days; f r = 0.332 days ad f r = 0.99 days; for the slow dissolution fraction times were f r = 146.95 days; f r = 63 days; f r = 86.64 days; f r = 79.66 days and f r = 59.84 days. These values indicate that these metals present a moderate absorption level in SLF, and may be classified as M type, according to the International Commission on Radiological Protection (ICRP). The use of solubility parameters allowed a better description of the kinetic behaviour of the sludge in the human body and, therefore, a better evaluation of the worker’s risk to

  8. Import of metal scrap - risks associated with radioactivity

    International Nuclear Information System (INIS)

    Elert, M.

    1992-11-01

    There is a growing concern in Sweden for the possibility that imported metal scrap is radioactive. The recent political and economical changes in eastern Europe and the increased cooperation with the CEC has affected Swedens import. In the last years, the import of metal scrap from the former USSR has increased considerably. In view of recent incidents, when radioactive materials have been found, the Swedish Radiation Protection Institute has detected a need for identifying the potential risk sources and evaluating the magnitude of the risk associated with the import of metal scrap. The purpose of this report is to provide some background material concerning import statistics, use of metal scrap in Sweden and to identify potential sources of radioactive metal scrap. In addition, the radionuclides of most concern has been identified and the possibility of detecting them in metal scrap shipments is analyzed

  9. Metallurgical applications: fractography

    International Nuclear Information System (INIS)

    Meny, L.

    1978-01-01

    The principal metallurgical uses of the scanning electron microscope and the microprobe described here employ images obtained on a CRT from an electron signal or X rays. The various electron signals are the back scattered electrons, secondary electrons and absorbed electrons. The differences in the intensity of thee signals with the acceleration tension E 0 , the inclination angle β, the atomic number Z of the target and any potential applied to the sample give rise to contrasts: atomic number contrast, given by the sample current or the back scattered electrons; topographical contrast, given by the emission of the secondary electrons Δ that vary with α (the angle between the normal to the surface and the direction of the incident beam) [fr

  10. Shielding Gas and Heat Input Effects on the Mechanical and Metallurgical Characterization of Gas Metal Arc Welding of Super Martensitic Stainless Steel (12Cr5Ni2Mo) Joints

    Science.gov (United States)

    Prabakaran, T.; Prabhakar, M.; Sathiya, P.

    This paper deals with the effects of shielding gas mixtures (100% CO2, 100% Ar and 80 % Ar + 20% CO2) and heat input (3.00, 3.65 and 4.33kJ/mm) on the mechanical and metallurgical characteristics of AISI 410S (American Iron and Steel Institute) super martensitic stainless steel (SMSS) by gas metal arc welding (GMAW) process. AISI 410S SMSS with 1.2mm diameter of a 410 filler wire was used in this study. A detailed microstructural analysis of the weld region as well as the mechanical properties (impact, microhardness and tensile tests at room temperature and 800∘C) was carried out. The tensile and impact fracture surfaces were further analyzed through scanning electron microscope (SEM). 100% Ar shielded welds have a higher amount of δ ferrite content and due to this fact the tensile strength of the joints is superior to the other two shielded welds.

  11. Crisis management in metallurgical enterprises

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2014-07-01

    Full Text Available On the basis of report analysis which presents situation in metallurgical sector after 2008 the range of changes implemented in management of metallurgical enterprises was characterised. A definition approach to crisis management was suggested as the process when the enterprise is managed during the breakdown period in market condition of the economy in the way directed towards preventing the negative effects of crisis inside enterprises. The publication presents the key aspects of enterprise management in the period of collapse of the balance between the supply and demand on the metallurgical market.

  12. Proceedings of papers. 3. Balkan Metallurgical Conference

    International Nuclear Information System (INIS)

    Mickovski, Jovan

    2003-01-01

    This Conference aims to be a central event in the metallurgy research of Balkan, fulfilling the goals to present the most outstanding relevant developments in modern metallurgy; to inspire high standards of excellence in pure and applied metallurgy research; to attract outstanding scientists to present central lectures on modem metallurgical research, and on the challenges imposed by the needs of society; to inspire the young generation of metallurgists in Balkan and other countries. Following these lines, the 3. Balkan Conference on Metallurgy will provide a unique opportunity for academic and industrial metallurgists from the Balkan countries and wider, to exchange ideas, expertise, and experience on topics related to the theme of the Conference - Balkan Metallurgy in Search for New Ways of Development. The aim of the organizers was to bring together distinguished experts, not only to present their work, but also to discuss the major scientific and technological challenges facing metallurgy in this millennium.The 6 sections of the conference were entitled: Section A: Extractive metallurgy; Section B: Physical metallurgy and materials science - ferrous metals and non ferrous metals; Section C: Management, maintenance control and optimization of metallurgical processes; Section D: New technologies and techniques; Section E: Refractory and powder; Section F: Corrosion and protection of metals. Papers relevant to INIS are indexed separately

  13. Refining of metallurgical silicon by directional solidification

    Energy Technology Data Exchange (ETDEWEB)

    Martorano, M.A., E-mail: martoran@usp.br [Department of Metallurgical and Materials Engineering, University of Sao Paulo, Av. Prof. Mello Moraes, 2463 Sao Paulo-SP, 05508-900 (Brazil); Neto, J.B. Ferreira, E-mail: jbfn@ipt.br [Laboratory of Metallurgy and Ceramics Materials, Institute for Technological Research, Av. Prof. Almeida Prado, 532, Sao Paulo-SP, 05508-901 (Brazil); Oliveira, T.S., E-mail: theo.usp@bol.com.br [Department of Metallurgical and Materials Engineering, University of Sao Paulo, Av. Prof. Mello Moraes, 2463 Sao Paulo-SP, 05508-900 (Brazil); Tsubaki, T.O., E-mail: tomoe@ipt.br [Laboratory of Metallurgy and Ceramics Materials, Institute for Technological Research, Av. Prof. Almeida Prado, 532, Sao Paulo-SP, 05508-901 (Brazil)

    2011-02-25

    The directional solidification of a typical and a previously refined metallurgical silicon was carried out in a vertical Bridgman furnace. The mold velocity out of the hot zone of the furnace changed from one experiment to another in the range between 5 and 110 {mu}m s{sup -1}. Samples were extracted from the cylindrical ingots obtained in the experiments to investigate the effects of the mold velocity on the micro and macrostructures and on the concentration profiles of impurities along the ingots. At the lowest mold velocity, the macrostructures consist of columnar grains oriented approximately parallel to the ingot axis. As velocity increases, grains become thinner and more inclined in the radial direction. Precipitated particles containing Si, Fe, Al, and Ti are observed at the top of all ingots and, as the mold velocity increases, they are also seen at the ingot bottom and middle. The concentration profiles of several impurities have been measured along the ingots by inductively coupled plasma atomic emission spectrometry (ICP), indicating an accumulation of impurities at the ingot top. Consequently, the bottom and middle of the ingots are purer than the corresponding metallurgical silicon from which they solidified. Slices from the ingot bottom have also been analyzed by the glow discharge mass spectrometry technique (GDMS), allowing measurement of impurity concentrations that were below the quantification limit of the ICP. The purification effect and the accumulation of impurities at the ingot top are more pronounced as the mold velocity decreases. In the ingots obtained from the typical metallurgical silicon at the lowest mold velocities (5 and 10 {mu}m s{sup -1}), except for Al, all impurities are in concentrations below an important maximum limit for the feedstock of solar grade silicon. At the same mold velocities, the concentrations of Fe, Ti, Cu, Mn, and Ni measured at the bottom of the ingots obtained from both types of metallurgical silicon (typical

  14. Control of innovation activity in a competitive metallurgical business

    Science.gov (United States)

    Bogdanov, S. V.

    2010-12-01

    Certain competitive advantages of a manufacturer on a goods market can be provided if one creates conditions for bifurcation development of an innovation process in metallurgical business under conditions of market uncertainty of a demand for goods of a specified consumer quality and determines the technical-and-economic versions of stable operation of a production system for performing orders of metal product consumers.

  15. Plasma technology in metallurgical processing

    Energy Technology Data Exchange (ETDEWEB)

    Haile, O.

    1995-12-31

    This literature work is mainly focusing on the mechanisms of plasma technology and telling about metallurgical processing, particularly iron and steelmaking as well as the advantage of the unique properties of plasma. The main advantages of plasma technology in metallurgical operations is to direct utilization of naturally available raw materials and fuels without costly upgrading andlor beneficiation, improved environmental impact, improve process control, significant amplification of reactor and process equipment utilization and increased efficiency of raw materials, energy and man power. This literature survey is based on the publication `plasma technology in metallurgical processing` presents a comprehensive account of the physical, electrical, and mechanical aspects of plasma production and practical processing. The applications of plasma technology in metallurgical processing are covered in depth with special emphasis on developments in promising early stages. Plasma technology of today is mature in the metallurgical process applications. A few dramatic improvements are expected in the near future this giving an impetus to the technologists for the long range planning. (18 refs.) (author)

  16. Monitoring of essential and toxic metals in imported herbal teas ...

    African Journals Online (AJOL)

    ADOWIE PERE

    concentrated and in turn enter the food chain and ultimately pose serious human health risk to consumers (Ansari et al., 2007; Weldegebriel et al.,. 2012; Rezaee et al., 2014). However, the evaluation of essential and toxic metals in teas is of great importance considering the potential health risk to habitual tea drinkers if ...

  17. 19 CFR 19.22 - Withdrawal of metal refined in part from imported crude metal and in part from crude metal...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Withdrawal of metal refined in part from imported crude metal and in part from crude metal produced from imported materials. 19.22 Section 19.22 Customs... § 19.22 Withdrawal of metal refined in part from imported crude metal and in part from crude metal...

  18. RISKS IDENTIFYING IN INNOVATION DEVELOPMENT PROGRAMS OF METALLURGICAL ENTERPRISES

    Directory of Open Access Journals (Sweden)

    Євгенія Сергіївна ШВЕЦЬ

    2015-05-01

    Full Text Available The theoretical aspects of risk management in innovative programs of metallurgical enterprises are examined; the causes of risks, their classification on the basic signs and stages of the risk management process and methods of risk management in innovative programs of metallurgical enterprises are described in modern conditions of Ukraine. The advanced and simplified methods of audit risk are characterized and the most common methods of quantitative risk analysis are listed. Conclusions were made about the essential things that are important especially for risks arising in the company due innovative development selecting.

  19. Natural arsenic attenuation via metal arsenate precipitation in soils contaminated with metallurgical wastes: II. Cumulative evidence and identification of minor processes

    International Nuclear Information System (INIS)

    Gutiérrez-Ruiz, M.E.; Ceniceros-Gómez, A.E.; Villalobos, M.; Romero, F.; Santiago, P.

    2012-01-01

    Highlights: ► Aqueous As in soils surrounding a smelting plant decreased through a natural attenuation process. ► As in water extracts from soils matched thermodynamic equilibrium modeling results. ► Modeling indicates that lead arsenates of low-solubility control As mobility. ► Sequential chemical extractions are consistent with the solubility behavior of lead arsenates. ► Microscopic evidence of lead arsenates was obtained by HRTEM–EDS. - Abstract: Accurate identification of individual As species in contaminated environments is critical because the toxicology, mobility and adsorptive properties of this element may vary substantially with its chemical forms and oxidation states. The goal of this work was to relate the geochemical behavior of As in soils contaminated by a lead smelter in Mexico, with its chemical speciation, and to achieve direct identification of low-solubility poorly-crystalline metal arsenates. Arsenic was identified as the most mobile trace element in the wastes from the smelting plant. Arsenic solubility in soils was significantly lower than its solubility in wastes, showing natural attenuation of this element. Its solubility in soil was quantitatively described in selected samples through thermodynamic equilibrium modeling. The results indicated that As solubility is controlled by solid Pb and Cu arsenate formation. The behaviors of the sequential chemical extractions were consistent with the presence of the predicted arsenates. Microscopic evidence of the formation of solid metal arsenates were obtained in fine soil fractions of selected samples with high As contents, by using the following complementary techniques: X-ray diffraction, scanning electron microscopy and transmission electron microscopy, both coupled with energy dispersive X-ray spectroscopy, and the latter with a high angle annular dark field detector. All results supported the formation of low-solubility Pb arsenates as controlling As mobility in the samples

  20. La cadena de suministro del sector metalúrgico: un análisis de sus principales eslabones (The Supply Chain in the metallurgical sector: an analysis of the main links

    Directory of Open Access Journals (Sweden)

    Patricia Carbajo-de-Lera

    2011-12-01

    Full Text Available Los directivos actuales conciben que la competencia ya no es empresa frente a empresa, sino que desborda este plano generándose una competencia cadena de suministro frente a cadena de suministro. Por ello, la gestión de la cadena de suministro se convierte en un elemento clave para la supervivencia empresarial y la obtención de ventajas competitivas. El diseño de la cadena de suministro viene definido, en buena parte, por las características del sector al que pertenece. En consecuencia, es de interés realizar análisis sectoriales. El presente trabajo tiene como objetivo analizar la cadena de suministro en un sector de gran importancia en la economía española, como es el metalúrgico. En concreto, buscamos determinar su cadena de suministro, definiendo los principales eslabones que la configuran y las relaciones entre ellos.Abstract: In the current business context, competition is no longer firm against firm, but has moved on to a higher plane, with the generation of supply chain against supply chain competition.  Therefore, Supply Chain Management (SCM has strategic relevance as a source of competitive advantage. The design of the supply chain is defined largely by the characteristics of the sector. Consequently, sectorial analysis is required. The aim of this paper is to analyze the supply chain of the metallurgical sector. Specifically, it will be focused on determining its supply chain and defining its main links and relationships.

  1. Radioactivity of raw materials, metallurgical and casting products

    International Nuclear Information System (INIS)

    Hons, J.

    2000-01-01

    At present, the radioactive contamination of metallurgical products and initial materials represent a potential obstacle in foreign and domestic trade. It is of course an undesirable threat o the living environment on the one side and, at the same time, a new incorrectly used means for suppressing competition and forming a protection 'umbrella' of the national market to desirable imports on the other hand

  2. Três anos de acidentes do trabalho em uma metalúrgica: caminhos para seu entendimento Three years of work-related accidents in a metallurgic plant: ways to its understanding

    Directory of Open Access Journals (Sweden)

    Cláudia Giglio de Oliveira Gonçalves

    2011-02-01

    Full Text Available O objetivo deste artigo é descrever, através de estratégias metodológicas quantitativas e qualitativas, os acidentes do trabalho ocorridos em três anos numa indústria metalúrgica do interior de São Paulo para compreender suas possíveis causas. Trata-se de um estudo de casos de uma indústria; foram estudados 336 acidentes em três anos, utilizando-se três procedimentos: análise dos registros dos acidentes, entrevistas (166 acidentados e realização de grupos focais (111 trabalhadores. A proporção de incidência anual dos acidentes foi de 16,9%; 75 casos com afastamento superior a 15 dias; 51,2% ocorreram pela manhã, afetando caldeireiros (48,2%. Entre os entrevistados, escolaridade média de 8,8 anos e idade de 31 a 50 anos (55,4%; 64,5% já haviam sofrido outros acidentes e com maior ocorrência naqueles expostos ao ruído intenso (mais 90 dBA (53%. Nos grupos focais, identificaram-se percepções e sentimentos dos trabalhadores a respeito dos acidentes que não apareceram nas etapas anteriores. Através dos grupos focais pode-se identificar melhor os fatores que contribuem para os acidentes, como: pressões, realização de horas extras, baixos salários, condições de trabalho precárias e organização do trabalho.The objective of this study is to describe, by quantitative and qualitative methods, industrial accidents occurred during three years in a metallurgic plant in the rural area to understand the possible causes. It is a case study in a metallurgic plant where 336 accidents were studied in a 3-year period by means of three procedures: analysis of accidents' registers, interviews with 166 hurt workers, and the organization of Focal Groups (111 workers for discussion. The ratio of yearly incidence of accidents was 16.9%; 75 cases required more than 15 out-of-work days; 51.2% occurred in the morning and affected boilermakers (48.2%. Among the interviewed workers, average schooling was 8.8 years, age ranged from 31

  3. Supercritical water oxidation benchscale testing metallurgical analysis report

    International Nuclear Information System (INIS)

    Norby, B.C.

    1993-02-01

    This report describes metallurgical evaluation of witness wires from a series of tests using supercritical water oxidation (SCWO) to process cutting oil containing a simulated radionuclide. The goal of the tests was to evaluate the technology's ability to process a highly chlorinated waste representative of many mixed waste streams generated in the DOE complex. The testing was conducted with a bench-scale SCWO system developed by the Modell Development Corporation. Significant test objectives included process optimization for adequate destruction efficiency, tracking the radionuclide simulant and certain metals in the effluent streams, and assessment of reactor material degradation resulting from processing a highly chlorinated waste. The metallurgical evaluation described herein includes results of metallographic analysis and Scanning Electron Microscopy analysis of witness wires exposed to the SCWO environment for one test series

  4. Concentrations of Heavy Metals in NPK Fertilizers Imported in Serbia

    Directory of Open Access Journals (Sweden)

    Jelena Milinović

    2008-01-01

    Full Text Available Concentrations of Pb, Cd, Cu and Mn in sixteen NPK fertilizers imported and widely used in Serbia were determined by flame atomic absorption spectrometry (AAS. The results show that contents of heavy metals varied significantly in different fertilizers dependingon N:P:K ratio and fertilizer origin. Pb and Cd contents in water solution of fertilizers occurred at low ranges: 2.0-3.1 and 0.03- 1.56 mg/kg, respectively. An NPK (15:15:15 fertilizer from Romania was found to contain the highest concentration of Pb and Cd as impurities. Cu content, ranging from 7.1 to 974.7 mg/kg, was the highest in coloured fertilizers from Hungary, the Netherlands and Greece. Mn value in a Hungarian NPK product (10:10:20 exceeds the average Mn value in soil. The data indicate variable contents of heavy metals in fertilizers, some of which are significantly higher than natural concentrations in soil, which suggests that they need to be continuously monitored.

  5. Metallurgical electrochemistry: the interface between materials science and molten salt chemistry

    International Nuclear Information System (INIS)

    Sadoway, D.R.

    1991-01-01

    Even though molten salt electrolysis finds application in the primary extraction of metals (electrowinning), the purification and recycling of metals (electrorefining), and in the formation of metal coatings (electroplating), the technology remains in many respects underexploited. Electrolysis in molten salts as well as other nonaqueous media has enormous potential for materials processing. First, owing to the special attributes of nonaqueous electrolytes electrochemical processing in these media has an important role to play in the generation of advanced materials, i.e., materials with specialized chemistries or tailored microstructures (electrosynthesis). Secondly, as environmental quality standards rise beyond the capabilities of classical metals extraction technologies to comply, molten salt electrolysis may prove to be the only acceptable route from ore to metal. Growing public awareness of pollution from the metals industry could stimulate a renaissance in molten salt electrochemistry. Challenges facing metallurgical electrochemistry as relates to the environment fall into two categories: (1) improving existing electrochemical technology, and (2) developing clean electrochemical technology to displace current nonelectrochemical technology. In both instances success hinges upon the discovery of advanced materials and the ecologically sound extraction of metals, the close coupling between materials science and molten salt chemistry is manifest. (author) 6 refs

  6. Wear and corrosion performance of metallurgical coatings in sodium

    International Nuclear Information System (INIS)

    Johnson, R.N.; Farwick, D.G.

    1980-01-01

    The friction, wear, and corrosion performance of several metallurgical coatings in 200 to 650 0 C sodium are reviewed. Emphasis is placed on those coatings which have successfully passed the qualification tests necessary for acceptance in breeder reactor environments. Tests include friction, wear, corrosion, thermal cycling, self-welding, and irradiation exposure under as-prototypic-as-possible service conditions. Materials tested were coatings of various refractory metal carbides in metallic binders, nickel-base and cobalt-base alloys and intermetallic compounds such as the aluminides and borides. Coating processes evaluated included plasma spray, detonation gun, sputtering, spark-deposition, and solid-state diffusion

  7. Magnetohydrodynamic research in fusion blanket engineering and metallurgical processing

    International Nuclear Information System (INIS)

    Tokuhiro, A.

    1991-11-01

    A review of recent research activities in liquid metal magnetohydrodynamics (LM-MHDs) is presented in this article. Two major reserach areas are discussed. The first topic involves the thermomechanical design issues in a proposed tokamak fusion reactor. The primary concerns are in the magneto-thermal-hydraulic performance of a self-cooled liquid metal blanket. The second topic involves the application of MHD in material processing in the metallurgical and semiconductor industries. The two representative applications are electromagnetic stirring (EMS) of continuously cast steel and the Czochralski (CZ) method of crystal growth in the presence of a magnetic field. (author) 24 figs., 10 tabs., 136 refs

  8. IMPORTANCE OF GENETIC SUSCEPTIBILITY TO METAL POISONING IN FORENSIC TOXICOLOGY

    OpenAIRE

    SÖYLEMEZOĞLU, Tülin; KAYAALTI, Zeliha

    2018-01-01

    Living organisms require varying amounts of essential metals like iron,calcium, chromium, copper, manganese, molybdenum, and zinc. Heavy metals suchas arsenic, cadmium, lead and mercury, have no vital or beneficial effect onorganisms. All of these metals are toxic at different concentrations and theiraccumulation of human body can cause chronic toxic effects and serious illness.Human organism accumulates heavy metals as a result of lifestyle andenvironmental pollution.  Toxic metalsdisrupt me...

  9. Cleaner metallurgical industry in Serbia: a road to the sustainable development

    Directory of Open Access Journals (Sweden)

    D. Panias

    2009-01-01

    Full Text Available Since the sustainable development has been a global and fundamental objecttive, a metallurgical industrial sector faces some of the most difficult sustainability challenges of any industrial sector. On the other hand, the metallurgical production in Serbia is a very important part of the economy. Due to present facilities and technologies, metallurgical companies face a great challenge to fulfill the requirements introduced by legislature referring to the cleaner production and sustainable development. The state of art in the production, facilities, pollution with some answers to imposed challenges is presented.

  10. Estimation of metallurgical parameters of flotation process from froth visual features

    Directory of Open Access Journals (Sweden)

    Mohammad Massinaei

    2015-06-01

    Full Text Available The estimation of metallurgical parameters of flotation process from froth visual features is the ultimate goal of a machine vision based control system. In this study, a batch flotation system was operated under different process conditions and metallurgical parameters and froth image data were determined simultaneously. Algorithms have been developed for measuring textural and physical froth features from the captured images. The correlation between the froth features and metallurgical parameters was successfully modeled, using artificial neural networks. It has been shown that the performance parameters of flotation process can be accurately estimated from the extracted image features, which is of great importance for developing automatic control systems.

  11. Aspectos metalúrgicos de revestimentos dissimilares com a superliga à base de níquel inconel 625 Metallurgical aspects of dissimilar weld overlays of inconel 625 nickel based superalloys

    Directory of Open Access Journals (Sweden)

    Cleiton Carvalho Silva

    2012-09-01

    Full Text Available Prolongar a vida útil e aumentar a confiabilidade de equipamentos e tubulações de plantas de produção e processamento de petróleo é uma busca constante no setor de petróleo e gás. Tais aspectos dependem essencialmente do uso de ligas resistentes à corrosão. Neste contexto, a soldagem de revestimento com superligas à base de níquel tem sido uma alternativa interessante, pois confere aos equipamentos uma alta resistência à corrosão com um custo inferior, se comparado à fabricação de componentes ou tubulações maciças com superligas. Assim, o objetivo do presente trabalho foi investigar o comportamento metalúrgico de revestimento de superliga à base de níquel do tipo Inconel 625 depositados pelo processo TIG com alimentação de arame frio. As soldagens foram realizadas em uma bancada robotizada, empregando uma fonte eletrônica de soldagem com sistema de aquisição de dados para o monitoramento dos sinais de corrente e tensão. A caracterização microestrutural foi realizada através das técnicas de microscopia eletrônica de varredura (MEV e transmissão (MET, espectroscopia de energia dispersiva de raios-X (EDS. Os resultados mostraram que a microestrutura do metal de solda foi constituída por uma matriz γ com fases secundárias ricas em Nb. Foi encontrada a formação de precipitados complexos de carbonetos/nitretos de Ti e Nb.To extend the life and reliability of pipes and equipment in oil & gas production and processing settings is a continuous demand. These aspects are essentially dependent on corrosion resistant alloys used. In this context, the weld overlay with Ni-based superalloys is a great interesting alternative, since improve the corrosion resistance without increase the cost of manufacture when compared to massive equipment. Thus, the objective of this study was to evaluate the metallurgical aspects of Inconel 625 weld overlays deposited by GTAW cold wire feed process. The welds were performed using a

  12. A metallurgical study of some viking swords

    Directory of Open Access Journals (Sweden)

    Williams, Alan

    2009-12-01

    Full Text Available While «pattern-welded» swords have been found all over Europe from sites dating from the Migration Period and into the Early Middle Ages, they were steadily supplanted during the Viking period by swords made out of a few pieces of iron and steel, or even a single piece of steel. Swords with «Ulfberht» or related inscriptions were the most famous of these. The results of the metallurgical study of 44 specimens from «Ulfberht» swords, as well as some other Viking-age swords, together with electron microanalyses carried out on selected examples, are presented here.

    Mientras que se han encontrado en toda Europa espadas forjadas mediante el sistema de ‘pattern welding’ (entrelazado de láminas formando patrones visibles, procedentes de yacimientos que se extienden desde el Periodo de las Migraciones bárbaras hasta la Alta Edad Media, durante el periodo vikingo fueron habitualmente reemplazadas por espadas forjadas a partir de unas pocas piezas de hierro y acero, o incluso de una única pieza de acero. Las más famosas de entre ellas fueron las espadas con la inscripción «Ulfbehrt» u otras relacionadas. Este artículo presenta los resultados del estudio metalúrgico de 44 ejemplares de espadas de «Ulfberht» y otras de época vikinga, así como los microanálisis efectuados sobre algunas muestras seleccionadas.

  13. Dor orofacial e absenteísmo em trabalhadores da indústria metalúrgica e mecânica Orofacial pain and absenteeism in workers of the metallurgic and mechanics industry

    Directory of Open Access Journals (Sweden)

    Josimari Telino de Lacerda

    2008-12-01

    Full Text Available O objetivo do estudo foi verificar a prevalência de dor orofacial e sua relação com absenteísmo em trabalhadores do setor metalúrgico e mecânico do município de Xanxerê, Santa Catarina. Realizou-se um estudo transversal envolvendo todos os trabalhadores do sexo masculino (n = 480 das 13 indústrias do setor no município. As informações foram coletadas por meio de entrevistas estruturadas. Informações sócio-demográficas, prevalência, severidade e localização de dor orofacial no último semestre, bem como sobre falta ao trabalho devido à dor orofacial, compuseram o questionário. Dados de identificação, setor e turno de trabalho foram coletados nos departamentos de recursos humanos das empresas. Os dados foram analisados por meio de estatística descritiva e testes de associação de qui-quadrado de Pearson entre absenteísmo e dor orofacial. A prevalência de dor orofacial foi de 66,1%, sendo dor de dente provocada ou dor de dente espontânea os tipos mais frequentes. O absenteísmo devido a dor orofacial no último semestre foi relatado por 9,3% dos trabalhadores, mostrando-se associado à dor de dente espontânea (p The objective of this study was to assess the prevalence of orofacial pain and its association with absenteeism in worke rs of the metallurgic and mechanics industry of the city of Xanxerê, Brazil. A cross sectional study was performed involving all male workers(n=480 of the 13 industries of the sector in the city. The information was collected by means of structured interviews. Socio-demographic information, prevalence, severity and localization of orofacial pain in the last semester as well as on absenteeism due to orofacial pain formed the questionnaire. Identification data, work sector and shift were collected in the departments of human resources of the companies. The data were assessed using descriptive statistics and Pearson chi-squared tests between absenteeism and pain in the orofacial region. The

  14. Experimental research on quality features of metallurgical coke

    Science.gov (United States)

    Andrei, V.; Constantin, N.

    2015-06-01

    From all the solid fuels, the metallurgical coke is the most used in obtaining iron in the blast furnace. Together with the iron ore, manganese ore and fluxes, it constitutes the basis of raw materials and materials for elaborating pig iron. This paper presents the results of laboratory investigations by the authors to determine the most important quality characteristics of some types of coke used in the blast furnace charge.

  15. [Metal ions: important co-players in aseptic loosening].

    Science.gov (United States)

    Cadosch, D; Schlett, C L; Gautschi, O P; Frei, H C; Filgueira, L

    2010-08-01

    The aims of this review were to discuss the different mechanisms of biocorrosion of orthopaedic metal implants in the human body, as well as the effects of the released metal ions on bone metabolism and the immune system in regard to their involvement in the pathophysiological mechanisms of aseptic loosening and metal hypersensitivity. Implant failure due to aseptic loosening is thought to occur in about 10-15% of cases. A review of the literature (using PubMed with the search terms: biocorrosion, metal ions and bone metabolism) was performed. Additionally, we discuss our research results in the field of aseptic loosening. Despite a great effort in developing new implants, metal devices used in orthopaedic and trauma surgery remain prone to biocorrosion by several mechanisms including the direct corrosion by osteoclasts, leading to the production of significant amounts of wear particles and metal ions. In addition to the well documented increased osteolytic activity caused by large (in the nanometer range) wear particles, increasing evidence strongly suggests that the released metal ions contribute to the pathophysiological mechanism of aseptic loosening. Metal ions stimulate both the immune system and bone metabolism through a series of direct and indirect pathways leading to an increased osteolytic activity at the bone-implant interface. To date, revision surgery remains the only option for the treatment of a failed orthopaedic implant caused by aseptic loosening. A better understanding of the complex pathophysiological mechanisms (including the effects caused by the released metal ions) of aseptic loosening may have a significant potential in developing novel implants and therapies in order to reduce the incidence of this complication. Georg Thieme Verlag KG Stuttgart, New York.

  16. Mining-metallurgical projects for the production of uranium concentrates

    International Nuclear Information System (INIS)

    Ajuria-Garza, S.

    1983-01-01

    This report presents an overall view of a complete project for a mining-metallurgical complex for the production of uranium concentrates. Relevant aspects of each important topic are discussed as parts of an integrated methodology. The principal project activities are analyzed and the relationships among the various factors affecting the design are indicated. A list of 96 principal activities is proposed as an example. These activities are distributed in eight groups: initial evaluations preliminary feasibility studies, project engineering, construction, industrial operation, decommissioning and post-decommissioning activities. The environmental impact and the radiological risks due to the construction and operation of the mining metallurgical complex are analyzed. The principles of radiological protection and the regulations, standards and recommendations for radiological protection in uranium mines and mills are discussed. This report is also a guide to the specialized literature: a bibliography with 765 references is included. (author)

  17. Monitoring of essential and toxic metals in imported herbal teas ...

    African Journals Online (AJOL)

    Twenty eight samples of commonly consumed herbal tea bags were purchased from major supermarkets in Port-Harcourt, Yenagoa and Owerri in Southern Nigeria. They were digested, ashed and analysed using atomic absorption spectroscopy (AAS). Heavy metal concentration varied among the different brands of herbal ...

  18. Evaluation of solubility in simulated lung fluid of metals present in the sludge from a metallurgical industry to produce metallic zinc; Avaliacao da solubilidade em liquido pulmonar simulado dos metais presentes no rejeito gerado por uma industria metalurgica de zinco

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Rosilda Maria Gomes de

    2012-07-01

    The objective of this study was to determine the solubility parameters (rapid and slow dissolution rates, rapid and slow dissolution fractions) metal particles present in a pile of sludge accumulated under exposure to weathering from the Cia Mercantil Inga, located at the Ilha da Madeira, Sepetiba Bay, Rio de Janeiro. Plant samples collected in the neighboring of the pile and bioindicators placed in the region and collected after some months indicated that the inhabitants of Ilha da Madeira have been exposed to trace elements such zinc, cadmium, mercury and lead, produced during the processing of zinc minerals (hemimorphite - Zn{sub 4}(OH){sub 2}Si{sub 2}O{sub 7}.H{sub 2}O, and willemite - Zn{sub 2}SiO{sub 4}). A static dissolution test in vitro was used to determine the solubility parameters using a simulated lung fluid (SLF), on a time basis ranging from 10 min to 1 year. The metal concentrations in the sludge samples and in the SLF were determined using Particle Induced X-rays Emission (PIXE). In conclusion, this study confirms the harmful effects on the neighboring population of the airborne particles containing these metals that came from the sludge. The solubility parameters obtained for Zn, Cd, Cr, Ni and Mn present in the rapid dissolution fraction in SLF were 0.945; 0.473; 0.226; 0.300 and 0.497, respectively, and the corresponding times for half life of dissolution of the rapid fraction were f{sub r} = 2.082 days; f{sub r} = 0.09 days; f{sub r} = 0.37 days; f{sub r} = 0.332 days ad f{sub r} = 0.99 days; for the slow dissolution fraction times were f{sub r} = 146.95 days; f{sub r} = 63 days; f{sub r} = 86.64 days; f{sub r} = 79.66 days and f{sub r} = 59.84 days. These values indicate that these metals present a moderate absorption level in SLF, and may be classified as M type, according to the International Commission on Radiological Protection (ICRP). The use of solubility parameters allowed a better description of the kinetic behaviour of the sludge in

  19. Effects of mechanical activation on the carbothermal reduction of chromite with metallurgical coke

    Directory of Open Access Journals (Sweden)

    Kenan Yıldız

    2010-06-01

    Full Text Available The carbothermal reduction of mechanically activated chromite with metallurgical coke under an argon atmosphere was investigated at temperatures between 1100 and 1400°C and the effects of the mechanical activation on chromite structure were analyzed by x-ray diffraction (XRD and scanning electron microscopy (SEM. An increase in specific surface area resulted in more contact points. The activation procedure led to amorphization and structural disordering in chromite and accelerated the degree of reduction and metalization in the mixture of chromite and metallurgical coke. Carbothermal reduction products were analzed by using scanning electron microscopy (SEM/EDS.

  20. Metals Are Important Contact Sensitizers: An Experience from Lithuania

    Directory of Open Access Journals (Sweden)

    Kotryna Linauskienė

    2017-01-01

    Full Text Available Background. Metals are very frequent sensitizers causing contact allergy and allergic contact dermatitis worldwide; up-to-date data based on patch test results has proved useful for the identification of a problem. Objectives. In this retrospective study prevalence of contact allergy to metals (nickel, chromium, palladium, gold, cobalt, and titanium in Lithuania is analysed. Patients/Methods. Clinical and patch test data of 546 patients patch tested in 2014–2016, in Vilnius University Hospital Santariskiu Klinikos, was analysed and compared with previously published data. Results. Almost third of tested patients (29.56% were sensitized to nickel. Younger women were more often sensitized to nickel than older ones (36% versus 22.8%, p=0.0011. Women were significantly more often sensitized to nickel than men (33% versus 6.1%, p<0.0001. Younger patients were more often sensitized to cobalt (11.6% versus 5.7%, p=0.0183. Sensitization to cobalt was related to sensitization to nickel (p<0.0001. Face dermatitis and oral discomfort were related to gold allergy (28% versus 6.9% dermatitis of other parts, p<0.0001. Older patients were patch test positive to gold(I sodium thiosulfate statistically significantly more often than younger ones (44.44% versus 21.21%, p=0.0281. Conclusions. Nickel, gold, cobalt, and chromium are leading metal sensitizers in Lithuania. Cobalt sensitization is often accompanied by sensitization to nickel. Sensitivity rate to palladium and nickel indicates possible cross-reactivity. No sensitization to titanium was found.

  1. METALLURGICAL PROGRAMS: CALCULATION OF MASS FROM VOLUME, DENSITY OF MIXTURES, AND CONVERSION OF ATOMIC TO WEIGHT PERCENT

    Science.gov (United States)

    Degroh, H.

    1994-01-01

    The Metallurgical Programs include three simple programs which calculate solutions to problems common to metallurgical engineers and persons making metal castings. The first program calculates the mass of a binary ideal (alloy) given the weight fractions and densities of the pure components and the total volume. The second program calculates the densities of a binary ideal mixture. The third program converts the atomic percentages of a binary mixture to weight percentages. The programs use simple equations to assist the materials staff with routine calculations. The Metallurgical Programs are written in Microsoft QuickBASIC for interactive execution and have been implemented on an IBM PC-XT/AT operating MS-DOS 2.1 or higher with 256K bytes of memory. All instructions needed by the user appear as prompts as the software is used. Data is input using the keyboard only and output is via the monitor. The Metallurgical programs were written in 1987.

  2. Powder metallurgical high performance materials. Proceedings. Volume 4: late papers

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    This is the fourth volume (late papers) of the 15th International Plansee seminar 2001 which general theme was 'Powder metallurgical high performance materials'. The seminar looked beyond the refractory metals and cemented carbides, which remain as its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. This volume 4 contains papers dealing with high performance P/M metals (ITER and fusion reactors, solid targets, materials microstructure, novel alloys, etc.), P/M hard materials ( production and characterization, tungsten carbides, titanium carbides, microstructural design, coatings composition and performance, etc.) and general topics. From 37 papers 24 correspond to INIS subject scope and they were indexed separately. (nevyjel)

  3. Friction welding thermal and metallurgical characteristics

    CERN Document Server

    Yilbas, Bekir Sami

    2014-01-01

    This book provides insight into the thermal analysis of friction welding incorporating welding parameters such as external, duration, breaking load, and material properties. The morphological and metallurgical changes associated with the resulting weld sites are analysed using characterization methods such as electron scanning microscope, energy dispersive spectroscopy, X-ray Diffraction, and Nuclear reaction analysis.

  4. Cyril Stanley Smith's Translations of Metallurgical Classics

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 6. Cyril Stanley Smith's Translations of Metallurgical Classics. Martha Goodway. General Article Volume 11 Issue 6 June 2006 pp 63-66. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Cyril Stanley Smith's Translations of Metallurgical Classics

    Indian Academy of Sciences (India)

    A remarkable contribution of Professor Cyril Stanley Smith was the translation of metallurgical classics into English from several languages - both ancient and modem ... He had not prepared for the role of technical translator. His wife,. Alice Kimball Smith, in oral history interviews made for Harvard. University related how his ...

  6. Utilization of secondary energy resources of metallurgical ...

    African Journals Online (AJOL)

    ... with a heat output of 4200 kW, a working agent R 600, a source of low-potential heat-circulating water: a 460 kW gas engine. The proposed scheme showed high efficiency of power supply of the town in comparison with the gas boiler. Keywords: heat pump; internal combustion engine metallurgical plant; energy efficiency ...

  7. Biological activity and toxicitiy of imported and synthetic metal ...

    African Journals Online (AJOL)

    ... of green alga Scendesmus obliquus. The toxicity of surfactants to Scendesmus obliquus are arranged in the order: imported fluid > Synthetic fluid > S+ D > I+A> S+B> I+ C> I+B > I+D > I+D >S+A > I+4. These results prove that, the toxicity of fluids depends on its chemical structure. Egyptian Journal of Biotechnology Vol.

  8. Heavy Metal Resistance Strategies of Acidophilic Bacteria and Their Acquisition: Importance for Biomining and Bioremediation

    Directory of Open Access Journals (Sweden)

    Claudio A Navarro

    2013-01-01

    Full Text Available Microbial solubilizing of metals in acid environments is successfully used in industrial bioleaching of ores or biomining to extract metals such as copper, gold, uranium and others. This is done mainly by acidophilic and other microorganisms that mobilize metals and generate acid mine drainage or AMD, causing serious environmental problems. However, bioremediation or removal of the toxic metals from contaminated soils can be achieved by using the specific properties of the acidophilic microorganisms interacting with these elements. These bacteria resist high levels of metals by using a few "canonical" systems such as active efflux or trapping of the metal ions by metal chaperones. Nonetheless, gene duplications, the presence of genomic islands, the existence of additional mechanisms such as passive instruments for pH and cation homeostasis in acidophiles and an inorganic polyphosphate-driven metal resistance mechanism have also been proposed. Horizontal gene transfer in environmental microorganisms present in natural ecosystems is considered to be an important mechanism in their adaptive evolution. This process is carried out by different mobile genetic elements, including genomic islands (GI, which increase the adaptability and versatility of the microorganism. This mini-review also describes the possible role of GIs in metal resistance of some environmental microorganisms of importance in biomining and bioremediation of metal polluted environments such as Thiomonas arsenitoxydans, a moderate acidophilic microorganism, Acidithiobacillus caldus and Acidithiobacillus ferrooxidans strains ATCC 23270 and ATCC 53993, all extreme acidophiles able to tolerate exceptionally high levels of heavy metals. Some of these bacteria contain variable numbers of GIs, most of which code for high numbers of genes related to metal resistance. In some cases there is an apparent correlation between the number of metal resistance genes and the metal tolerance of each

  9. Mathematical Modelling of the Price Range in the Procurement of Ferrous Scrap by Metallurgical Enterprises

    Directory of Open Access Journals (Sweden)

    Tatyana Aleksandrovna Ivanova

    2018-03-01

    Full Text Available For metallurgical enterprises, it is important to understand the limits of the most probable values of prices and geographical area for procurement of ferrous scrap in the regions. In order to define the maximal scrap prices in the regions, the authors have developed a mathematical model of “auction purchases”. This model equally assesses price competition between scrap consumers. When setting the price, we consider the territorial imbalances between scrap supply and demand in the regions; costs for scrap transportation from supplier to consumer; price level for scrap in the “windows for exports”. We calculate the lowest price according to the “export parity”. The results of the calculations allow evaluating a range of regional prices and interregional flows of scrap. This approach is unnown in the published works of Russian and foreign researchers. For calculations, we have developed a special software. The following initial data were used: data on railroad transportation of ferrous scrap in the Russian Federation provided by JSC Russian Railways; handbooks of railway tariffs 10–01 between railway stations of the Russian Federation; statistical data on prices of 3A metal scrap in the “windows for exports”. The article presents the formal structure of the model of “auction procurement”, the algorithm of its implementation and the results of calculations. The price level calculated according to the model of “auction procurement” can be used in management practice as potentially highest level of price, which can be reached in the conditions of competition between consumers of scrap in a situation when the negotiations are impossible. The proposed mathematical model allows a metallurgical enterprise to prove and implement a differentiated approach to the formation of regional prices of scrap, and to define regions for scrap purchasing.

  10. Future supply and demand of certain strategic metal imports in South Africa

    International Nuclear Information System (INIS)

    Dudas, J.S.J.

    1984-01-01

    While South Africa is richly endowed with minerals it is unfortunately almost wholly dependent on external markets for certain metals. Some of the most strategic metals are molybdenum, tungsten, cobalt and aluminium - essential in the steel, petrochemical and defense industries. The objective of this study is to investigate the probable future dependence of South Africa on its four most strategic metal imports. The project covers the uses of the metals locally, historical trends of supply and demand and a forecast of consumption for the next decade. Alternatives and substitutes for the metals as well as the possibility of reclamation after use are also considered. Existing local deposits and their potential economic viability were investigated to establish the possibility of extraction and processing in future years to enable South Africa to decrease it import dependence on these strategic metals

  11. Characterization of Nanocarbon Copper Composites Manufactured in Metallurgical Synthesis Process

    Science.gov (United States)

    Knych, Tadeusz; Kwaśniewski, Paweł; Kiesiewicz, Grzegorz; Mamala, Andrzej; Kawecki, Artur; Smyrak, Beata

    2014-08-01

    Currently, there is a worldwide search for new forms of materials with properties that are significantly improved in comparison to materials currently in use. One promising research direction lies in the synthesis of metals containing modern carbon materials ( e.g., graphene, nanotubes). In this article, the research results of metallurgical synthesis of a mixture of copper and two different kinds of carbon (activated carbon and multiwall carbon nanotubes) are shown. Samples of copper-carbon nanocomposite were synthesized by simultaneously exposing molten copper to an electrical current while vigorously stirring and adding carbon while under an inert gas atmosphere. The article contains research results of density, hardness, electrical conductivity, structure (TEM), and carbon decomposition (SIMS method) for the obtained materials.

  12. Modern recycling methods in metallurgical industry

    Directory of Open Access Journals (Sweden)

    M. Maj

    2010-04-01

    Full Text Available The contamination of environment caused by increased industrial activities is the main topic of discussions in Poland and in the world. The possibilities of waste recovery and recycling vary in different sectors of the industry, and the specific methods, developed and improved all the time, depend on the type of the waste. In this study, the attention has been focussed mainly on the waste from metallurgical industry and on the available techniques of its recycling

  13. Processing and utilization of metallurgical slag

    Directory of Open Access Journals (Sweden)

    Alena Pribulová

    2016-06-01

    Full Text Available Metallurgy and foundry industry create a huge amount of slags that are by-products in production of pig iron, steel and cast iron. Slag is produced in a very large amount in pyrometallurgical processes, and is a huge source of waste if not properly recycled and utilized. With rapid growth of industrialization, land available for land-filling of large quantity of metallurgical slag is being reduced all over the world and disposal cost is becoming increasingly higher. Metallurgical slag from different metallurgical processes treated and utilized in different ways based on different slag characteristics. The most economic and efficient option for reducing metallurgical waste is through recycling, which is a significant contribution to saving natural resources and reducing CO2 emissions. Characteristic of slags as well as its treatment and utilization are given in the paper. Slag from pig iron and steel production is used most frequently in building industry. From experiments using blast furnace slag and granulated blast furnace slag as gravel, and water glass as binder it can be concluded that that the best results – the best values of compression strength and tensile strength were reached by using of 18% of water glass as a solidification activating agent. According to cubic compression strength, mixture from 50% blast furnace gravel, 50% granulated blast furnace slag and 18% water glass falls into C35/45 class of concrete. Such concrete also fulfils strength requirements for road concrete, moreover, it even exceeds them considerably and, therefore, it can find an application in construction of road communications or in production of concrete slabs.

  14. Thermal crackling: study of the mechanical effects of quick temperature fluctuations on metallic surfaces

    International Nuclear Information System (INIS)

    Pradel, P.

    1984-05-01

    After a brief overview of the thermohydraulical conditions of liquid sodium leading to important temperature fluctuations near the metallic surfaces, the author examines the transfer modes of these fluctuations in the structure thickness and the long term mechanical effects. Dimensioning models based on thermal and metallurgical properties are under study for structures subject to such sodium loads [fr

  15. The beryllium production at Ulba metallurgical plant (Ust-Kamenogrsk, Kazakhstan)

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Tuzov, Y.V. [Ulba Metallurgical Plant (Zavod), Ust-Kamenogorsk, Abay prospect 102 (Kazakhstan)

    1998-01-01

    The Report includes data on beryllium production of Ulba metallurgical plant, located in Ust-Kamenogorsk (Kazakhstan). Beryllium production is showed to have extended technological opportunities in manufacturing semi-products (beryllium ingots, master alloys, metallic beryllium powders, beryllium oxide) and in production of structural beryllium and its parts. Ulba metallurgical plant owns a unique technology of beryllium vacuum distillation, which allows to produce reactor grades of beryllium with a low content of metallic impurities. At present Ulba plant does not depend on raw materials suppliers. The quantity of stored raw materials and semi-products will allow to provide a 25-years work of beryllium production at a full capacity. The plant has a satisfactory experience in solving ecological problems, which could be useful in ITER program. (author)

  16. Grinding-induced metallurgical alterations in the binder phase of WC-Co cemented carbides

    OpenAIRE

    Yang, Jing; Roa Rovira, Joan Josep; Schwind, Martin; Odén, M.; Johansonn Joesaar, M. P.; Llanes Pitarch, Luis Miguel

    2017-01-01

    The metallic binder phase dictates the toughening behavior of WC-Co cemented carbides (hardmetals), even though it occupies a relative small fraction of the composite. Studies on deformation and phase transformation of the binder constituent are scarce. Grinding represents a key manufacturing step in machining of hardmetal tools, and is well-recognized to induce surface integrity alterations. In this work, metallurgical alterations of the binder phase in ground WC-Co cemented carbides have be...

  17. Partitioning of metals in different binding phases of tropical estuarine sediments: importance of metal chemistry.

    Science.gov (United States)

    Chakraborty, Parthasarathi; Chakraborty, Sucharita; Vudamala, Krushna; Sarkar, Arindam; Nath, B Nagender

    2016-02-01

    Distribution of metals in different binding phases of estuarine sediments provides chemically significant description of metal-sediment interactions. This study describes the influences of ligand field stabilization energy (LFSE), Jahn-Teller effect, and water exchange rate (k-w) on metal distribution in different binding phases of estuarine sediments. It was found that Cu had highest affinity for organic binding phases in the studied sediments followed by Ni and Pb. However, Pb showed strong association with Fe/Mn oxide phases followed by Ni and Cu. Faster k-w of Cu (II) (1 × 10(9) s(-1)) increased the rate of complex formation of Cu(2+) ion with ligand in the organic phases. The Cu-ligand (from organic phase) complexes gained extra stability by the Jahn-Teller effect. The combined effects of these two phenomena and high ionic potential increased the association of Cu with the organic phases of the sediments than Ni and Pb. The smaller ionic radii of Ni(2+) (0.72 Å) than Pb(2+) (1.20 Å) increase the stability of Ni-ligand complexes in the organic phase of the sediments. High LFSE of Ni(II) (compared with Pb(2+) ions) also make Ni-organic complexes increasingly stable than Pb. High k-w (7 × 10(9) s(-1)) of Pb did not help it to associate with organic phases in the sediments. The high concentration of Pb in the Fe/Mn oxyhydroxide binding phase was probably due to co-precipitation of Pb(2+) and Fe(3+). High surface area or site availability for Pb(2+) ion on Fe oxyhydroxide phase was probably responsible for the high concentration of Pb in Fe/Mn oxyhydroxide phase. Increasing concentrations of Cu in organic phases with the increasing Cu loading suggest that enough binding sites were available for Cu in the organic binding phases of the sediments. This study also describes the influence of nature of sedimentary organic carbon (terrestrial and marine derived OC) in controlling these metal distribution and speciation in marine sediment.

  18. Bioaccumulation of heavy metals in commercially important marine fishes from Mumbai Harbor, India.

    Science.gov (United States)

    Velusamy, A; Satheesh Kumar, P; Ram, Anirudh; Chinnadurai, S

    2014-04-15

    Seventeen commercially important marine fish species were caught in Mumbai Harbor using a trawl net and evaluated using Atomic Absorption Spectroscopy and ICP-OES. It was found that certain species of fish contained lower levels of all metals tested. J. elongatus and C. dussumieri had the highest levels of all 8 metals tested. The heavy metal concentrations were significantly varied within and between the studied fishes (pheavy metals was observed. This investigation indicated that various levels of heavy metals exist in the fish species sampled, but those concentrations are within the maximum residual levels recommended by the European Union and FAO/WHO. Therefore, fish caught in Mumbai Harbor can be considered safe for human consumption. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution

    NARCIS (Netherlands)

    Leguedois, S.; Oort, van F.; Jongmans, A.G.; Chevalier, P.

    2004-01-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry

  20. Proceedings of the 6. international symposium on waste processing and recycling in the mineral and metallurgical industries : WALSIM : water, air and land sustainability issues in mineral and metal extraction

    International Nuclear Information System (INIS)

    Jia, C.Q.; Pickles, C.A.; Brienne, S.; Rao, S.R.

    2008-01-01

    The proceedings of the 2008 conference of metallurgists of CIM includes a collection 7 separate symposia, namely (1) aerospace materials and manufacturing, (2) water, air and land sustainability issues in mineral and metal extraction (WALSIM), (3) current status and future trends of functional nanometers, (4) recent developments in advanced high strength steels processing, (5) corrosion and wear of materials, (6) advanced characterization techniques applied to mineral, metals and materials, and (7) management in metallurgy. The WALSIM symposium dealt with environmental issues, with particular reference to the three topics of water, air and land sustainability associated with mineral and metal extraction, processing and fabrication. It provided an opportunity for scientists, engineers and plant operators to report on work aimed at achieving more efficient, environmentally sound and sustainable performance of the mineral and metals industry by enabling related organizations to exchange information on the latest developments in this field of activity with considerations of both industry and society. The sessions were entitled: resource recovery from waste material; by-products processing of slag, fly ash and electric arc furnace dust; metal recycling; wastewater and effluent treatment; gaseous pollutants treatment; and, sustainability and basic research. The symposium featured 43 presentations, of which 17 have been catalogued separately for inclusion in this database. refs., tabs., figs

  1. IOLOGICAL IMPORTANCE AND TOXICITY OF HEAVY METALS FOR BIOTA OF FRESHWATER BODIES (REVIEW)

    OpenAIRE

    I. Hrytsyniak; N. Kolesnyk

    2014-01-01

    Purpose. To investigate the sources of scientific information on biological functions of heavy metals (Fe, Zn, Mn, Cu, Ni, Co, Pb, Cd) and their negative effect on biota of fresh water bodies. Findings. A review of works of a variety of scientists showed that the majority of the studied heavy metals (Fe, Zn, Mn, Cum and Co) played an important role in vital functions of freshwater organisms. The significance of other studied heavy metals (Ni, Pb, and Cd) is probable or unknown. Besides bi...

  2. Application of logistic principles in metallurgical production

    Directory of Open Access Journals (Sweden)

    D. Malindžák

    2012-07-01

    Full Text Available Metallurgical production processes (MPP consist of continuous and discrete types of technology operation, transport, manipulation and storing processes regards the flow of material and also the equipment and machines. Other specifics are: long production cycles, great inertia, tree structure of production processes (from roots up to the leaves, high level of investments etc. These characteristics resulted in some specifics of production logistics. This article deals with these specifics and explains it using the conditions of production processes of continuous slab casting, their heating in push furnaces at rolling temperature and rolling itself in hot wideband steel mill.

  3. Inventory management in a metallurgical of the automotive industry

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Maia de Oliveira

    2015-12-01

    Full Text Available This article aims to analyze the importance of inventory management in a metallurgical company, located in Santo André city, in Grande São Paulo, since the inventory management is crucial within a company that wants to survive nowadays, by studying the main features and trends in the methods used for inventory control. In this case study the basic concepts for good control were considered, showing tools currently used in the market, providing data for material purchase, sales control, parts in stock, future orders, MRP, storage space, among others once many companies have high and unnecessary cost of stock for not being aware of the real importance of this control. It is felt that the logistics of the company should invest in technology by purchasing the MRP system, visiting fairs and attending seminars. This way, the company will have better inventory control thus consequently decrease the purchase of materials.

  4. DETERMINATION OF THE OPTIMAL CONTENT OF METAL-BURDEN FOR DIFFERENT GRADE MIX OF STEELS, MELTED IN THE STEEL-MAKING FURNACES NO 3 RUP “BELORUSSIAN METALLURGICAL WORKS”

    Directory of Open Access Journals (Sweden)

    N. V. Andrianov

    2004-01-01

    Full Text Available The program ''Calculation of the optimal metalburden composition" allowing to minimize the total cost of charging and of addition elements at the required output of molten metal of the predetermined chemical composition, has been developed on the basis of the offered technology.

  5. Arsenic and trace metals in commercially important bivalves, Anadara granosa and Paphia undulata

    Energy Technology Data Exchange (ETDEWEB)

    Mat, I. (Univ. of Malaya, Kuala Lumpur (Malaysia))

    1994-06-01

    The semi-culture of marine bivalves particularly Anadara granosa is of considerable economic importance in Malaysia. Currently, about 4-5000 ha of mudflats along the west coast are utilized for this purpose. Therefore, contamination of the highly productive mudflats with heavy metals tend to be accumulated in the filter feeding organisms such as bivalve molluscs which often serve as important environmental sinks of heavy metals. Bivalve molluscs, A. granosa and Paphia undulata are commercially important seafoods and popular among the locals in Malaysia. With this point in mind, it is intended to evaluate the concentration levels of arsenic as well as trace metals (Co, Cu, Ni, Cd, Zn, Cr and Pb) in both species derived from retail outlets in the city of Kuala Lumpur. Although this analysis may not indicate the site of capture but may act as a direct check on the contamination of seafoods available to the consumers. 17 refs., 2 tabs.

  6. Screening of variable importance for optimizing electrodialytic remediation of heavy metals from polluted harbour sediments

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Lejon, Tore; Ottosen, Lisbeth M.

    2015-01-01

    Using multivariate design and modelling, the optimal conditions for electrodialytic remediation (EDR) of heavy metals were determined for polluted harbour sediments from Hammerfest harbour located in the geographic Arctic region of Norway. The comparative importance of the variables, current......, it was shown that excluding the acidification time improved the PLS model, indicating the importance of applying a limited experimental domain that covers the removal phases of each heavy metal in the specific sediment. Based on PLS modelling, the optimal conditions for remediating the Hammerfest sediment were......) was computed and variable importance in the projection was used to assess the influence of the experimental variables. Current density and remediation time proved to have the highest influence on the remediation of the heavy metals Cr, Cu, Ni, Pb and Zn in the studied experimental domain. In addition...

  7. Heavy Metal Concentrations in an Important Mangrove Species, Sonneratia caseolaris, in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Mohd Fazlin Nazli

    2010-01-01

    Full Text Available Mangrove forests in Peninsular Malaysia are increasingly threatened by heavy metal pollution. Due to their unique location, mangroves receive heavy metal pollution from upstream areas and the sea. However, little is known about the capacity of mangrove plants to take up and store heavy metals. In this study, the concentrations of cadmium (Cd, chromium (Cr, copper (Cu, lead (Pb and zinc (Zn in an important mangrove species, Sonneratia caseolaris, were measured. It was found that the total concentrations of Cd, Cr, Cu, Pb, and Zn in the sediments were below the general critical soil concentrations. However, the total concentrations of Cu and Pb in both the roots and leaves of Sonneratia caseolaris exceeded the general normal upper range in plants. This study has therefore shown the potential of Sonneratia caseolaris as a phytoremediation species for selected heavy metals in Malaysian mangrove ecosystem.

  8. Distribution and enrichment of trace metals in surface marine sediments in the Gulf of Pozzuoli and off the coast of the brownfield metallurgical site of Ilva of Bagnoli (Campania, Italy).

    Science.gov (United States)

    Trifuoggi, Marco; Donadio, Carlo; Mangoni, Olga; Ferrara, Luciano; Bolinesi, Francesco; Nastro, Rosa Anna; Stanislao, Corrado; Toscanesi, Maria; Di Natale, Gabriella; Arienzo, Michele

    2017-11-15

    The distribution of metals in surface sediments of Gulf of Pozzuoli (GoP), embedding the former second Italian largest integrated steelworks of Bagnoli, was studied based on sediment dispersal, quality guidelines (SQGs) and quantitative pollution indices of the respective metals. As, Cd, Hg, Pb, Zn largely exceeded the limits. Hg had a mean of 5.8mg/kg, twentyfold higher the rule, accumulating primarily near Bagnoli site. The mean effective range quotient, m-ERM-Q, revealed a high potential for negative biological effects especially in the area nearby the Bagnoli site. The enrichment factor (EF) values were outstandingly high, >1.5 with values which were often ≥100. The geoaccumulation index, Igeo, was very critical for Cr, Cu, Hg and Ni, showing an Igeo in the range of strongly polluted (4polluted (Igeo>5). The principal component analysis (PCA) and Pearson's correlation matrix (CM), excluded significant contribution from weathering products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. IFM – SCIENTIFIC CENTRE OF THE DEVELOPMENT OF THE UKRAINIAN METALLURGICAL INDUSTRY

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2017-01-01

    Full Text Available The history of creation and development of the Institute of ferrous metallurgy of the Ukrainian Academy of Sciences named after Z. I. Nekrasov is regarded in the article. IFM has become the scientific centre of the development of the metallurgical industry of Ukraine. Researches of the outstanding scientists show their significant contribution in the development of the metallurgical science and implementation of their achievements in the production of the metallurgical industry of Ukraine. Analysis of publications. History of the Institute of the ferrous metallurgy is regarded in the fundamental works devoted to the development of the metallurgical industry in Ukraine and in the works published to the jubilee dates of the prominent scientists academicians Z. I. Nekrasov, V. I. Bol’shakov and others. The purpose of the article is to analyze the process of the creation of the Institute and the stages of its development in the 20th and 21st centuries and to define the influence of the economic and political situation in the country upon this process? To regard the role of the outstanding scientists and influence of their achievements on the development of the metallurgical industry of Ukraine. The history of IFM began in 1939 when it was organized in Kharkiv as a part of the Academy of Sciences of Ukraine. At the beginning of the Great Patriotic war the Institute was moved to Ufa – the capital of Bashkiria. During the war the scientists of the Institute tried to increase the output of metal and special steels for the defence industry. In 1943 the Institute moved to Moscow and then to Kiev. In 1952 it was decided to move the Institute to Dnepropetrovsk. In order to combine the scientific researches and production of metal. Z. I. Nekrasov was elected Director of the Institute. The departments of the Indtitute were headed by academicians Z. I. Nekrasov, A. P. Chekmariov, K. F. Starodubov, Correspondence Members of the Ukrainian Academy of Sciences

  10. Heavy metals in Australian grown and imported rice and vegetables on sale in Australia: health hazard.

    Science.gov (United States)

    Rahman, M Azizur; Rahman, Mohammad Mahmudur; Reichman, Suzie M; Lim, Richard P; Naidu, Ravi

    2014-02-01

    Dietary exposure to heavy metals is a matter of concern for human health risk through the consumption of rice, vegetables and other major foodstuffs. In the present study, we investigated concentrations of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) in Australian grown and imported rice and vegetables on sale in Australia. The mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn in Australian grown rice were 7.5 µg kg(-1), 21 µg kg(-1), 144 µg kg(-1), 2.9 mg kg(-1), 24.4 mg kg(-1), 166 µg kg(-1), 375 µg kg(-1), and 17.1 mg kg(-1) dry weight (d. wt.), respectively. Except Cd, heavy metal concentrations in Australian grown rice were higher than Bangladeshi rice on sale in Australia. However, the concentrations of Cd, Cr, Cu, and Ni in Indian rice on sale in Australia were higher than Australian grown rice. The concentrations of Cu and Ni in Vietnamese rice, and that of Cd, Cr, Cu, Ni, and Pb in Thai rice on sale in Australia were also higher than Australian grown rice. Heavy metal concentrations in Pakistani rice on sale in Australia were substantially lower than that in Australian grown rice. In Australian grown rice varieties, the concentrations of heavy metals were considerably higher in brown rice varieties than white rice varieties, indicating Australian brown rice as a potential source of dietary heavy metals for Australian consumers. The mean concentrations of heavy metals in Australian grown and Bangladeshi vegetables on sale in Australia were also determined. Some of the Australian grown and Bangladeshi vegetables contained heavy metals higher than Australian standard maximum limits indicating them as potential sources of dietary heavy metals for Australian consumers. Further investigation is required to estimate health risks of heavy metals from rice and vegetables consumption for Australian consumers. © 2013 Published by Elsevier Inc.

  11. Fast determination of impurities in metallurgical grade silicon for photovoltaics by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Hampel, J.; Boldt, F.M.; Gerstenberg, H.; Hampel, G.; Kratz, J.V.; Reber, S.; Wiehl, N.

    2011-01-01

    Standard wafer solar cells are made of near-semiconductor quality silicon. This high quality material makes up a significant part of the total costs of a solar module. Therefore, new concepts with less expensive so called solar grade silicon directly based on physiochemically upgraded metallurgical grade silicon are investigated. Metallurgical grade silicon contains large amounts of impurities, mainly transition metals like Fe, Cr, Mn, and Co, which degrade the minority carrier lifetime and thus the solar cell efficiency. A major reduction of the transition metal content occurs during the unidirectional crystallization due to the low segregation coefficient between the solid and liquid phase. A further reduction of the impurity level has to be done by gettering procedures applied to the silicon wafers. The efficiency of such cleaning procedures of metallurgical grade silicon is studied by instrumental neutron activation analysis (INAA). Small sized silicon wafers of approximately 200 mg with and without gettering step were analyzed. To accelerate the detection of transition metals in a crystallized silicon ingot, experiments of scanning whole vertical silicon columns with a diameter of approximately 1 cm by gamma spectroscopy were carried out. It was demonstrated that impurity profiles can be obtained in a comparably short time. Relatively constant transition metal ratios were found throughout an entire silicon ingot. This led to the conclusion that the determination of several metal profiles might be possible by the detection of only one 'leading element'. As the determination of Mn in silicon can be done quite fast compared to elements like Fe, Cr, and Co, it could be used as a rough marker for the overall metal concentration level. Thus, a fast way to determine impurities in photovoltaic silicon material is demonstrated. - Highlights: → We demonstrate a fast way to determine impurities in photovoltaic silicon by NAA. → We make first experiments of locally

  12. The use of radioisotope tracers in the metallurgical industries

    International Nuclear Information System (INIS)

    Easey, J.F.

    1987-01-01

    Radioisotope techniques have been widely used in the metallurgical industries for many years. They have been shown to be very suitable for studying large scale plant and, in many cases, they are the most suitable techniques for such investigations. Applications of radioisotope tracers to some specific metallurgical problems are discussed. (author)

  13. Cryogenic treatment of steel: from concept to metallurgical understanding

    DEFF Research Database (Denmark)

    Villa, Matteo; Somers, Marcel A. J.

    2017-01-01

    Subjecting steel to cryogenic treatment to improve its properties was conceived in the 30ies of the previous century. The proof of concept that properties, in particular wear resistance, can indeed be improved importantly, was reported in the next decades. Despite many investigations......, the metallurgical understanding of the microstructural changes involved in cryogenic treatment of steel has remained poor. It is believed that the improvement in wear resistance is promoted by an enhanced precipitation of carbides during tempering, but no explanation has been given as to how this enhanced...... precipitation can be obtained. In the last six years, the authors have applied in situ magnetometry, synchrotron X-Ray Diffraction and dilatometry to enlighten the phase transitions occurring in steels at cryogenic temperatures and to point out the connection between different treatment parameters...

  14. Utilisation of metallurgical by-products in road construction in the Czech Republic

    Science.gov (United States)

    Kresta, František

    2017-09-01

    Metallurgical by-products, primarily blast furnace slag and steel slag, have ranked among important alternative sources of fill as well as of material for the structural layers in highways. Main hazards of metallurgical by-products are closely connected to their chemical and mineralogical composition and they can be resulted in volume changes. Fears from possible deformations similar to the D47 motorway meant that metallurgical by-products were excluded from several public tenders of road construction. Comparison of blast furnace slag, steel slag and other metallurgical by products parameters allow us to define the most hazardous material as steelworks waste. Linear swelling of steelwork waste achieves more than 40% at 75°C and swelling pressure was higher than 1.5 MPa. Compositional heterogeneity of steelworks waste makes it difficult to establish the long-term behaviour of this material. At the present time we cannot ascertain which maximum values can be reached by deformation and what are the swelling pressures acting on the material while the volume changes are in progress.

  15. Survey of metallurgical recycling processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pemsler, J.P.

    1979-03-01

    In the year 2000, the US will consume about 3.2 x 10/sup 15/ Btu to produce the seven major nonferrous metals Al, Cu, Zn, Pb, Ni, Mg, and Ti. Of this amount, 82% will be used in the production of Al. It is projected that 0.6 x 10/sup 15/ Btu will be saved by the recycle of secondary metals. Major opportunities for increasing the extent of recycle and thereby increasing the energy savings are discussed. An inherent feature in the energistics of recycle is that physical processes such as magnetic separation, density separations, melting, and in some instances vaporization are far less energy intensive than are chemical processes associated with dissolution and electrowinning. It is in the domain of scrap of complex composition and physical form, difficult to handle by existing technology, that opportunities exist for new chemical recycle technology. Recycle of scrap metal of adequate grade is currently achieved through pyrometallurgical processes which, in many cases, are not very energy intensive as compared with hydrometallurgical processes. Preliminary flowsheets are presented for the recovery of value metals from batteries considered for use in vehicular propulsion and load leveling applications. The battery types examined are lead/acid, nickel/zinc, nickel/iron, zinc/chlorine, lithium-aluminum/iron sulfide, and sodium/sulfur. A flow sheet has been outlined for an integrated hydrometallurgical process to treat low-grade copper scrap. A fully integrated hydrometallurgical process is outlined, and costs and energy consumption are derived, for recovering zinc metal from electric furnace flue dusts. Costs and energy are high and the process does not appear to warrant development at this time. Improvement in the recycle of magnesium is associated primarily with improved recycle in the Al industry where Mg is an important alloy additive. Ni and Ti recycle are associated with improved collection and sorting of stainless steel and specialty alloys.

  16. Evaluation of Metallurgical Quality of Master Heat IN-713C Nickel Alloy Ingots

    Directory of Open Access Journals (Sweden)

    Binczyk F.

    2012-12-01

    Full Text Available The paper presents the results of evaluation of the metallurgical quality of master heat ingots and of the identification of non-metallic inclusions (oxides of Al., Zr, Hf, Cr, etc., which have been found in the shrinkage cavities formed in these ingots. The inclusions penetrate into the liquid alloy, and on pouring of mould are transferred to the casting, especially when the filtering system is not sufficiently effective. The specific nature of the melting process of nickel and cobalt alloys, carried out in vacuum induction furnaces, excludes the possibility of alloy refining and slag removal from the melt surface. Therefore, to improve the quality of castings (parts of aircraft engines, it is so important to evaluate the quality of ingots before charging them into the crucible of an induction furnace. It has been proved that one of the methods for rapid quality evaluation is an ATD analysis of the sample solidification process, where samples are taken from different areas of the master heat ingot. The evaluation is based on a set of parameters plotted on the graph of the dT/dt derivative curve during the last stage of the solidification process in a range from TEut to Tsol.

  17. Evaluation of Metallurgical Quality of Master Heat IN-713C Nickel Alloy Ingots

    Directory of Open Access Journals (Sweden)

    F. Binczyk

    2012-12-01

    Full Text Available The paper presents the results of evaluation of the metallurgical quality of master heat ingots and of the identification of non-metallic inclusions (oxides of Al., Zr, Hf, Cr, etc., which have been found in the shrinkage cavities formed in these ingots. The inclusions penetrate into the liquid alloy, and on pouring of mould are transferred to the casting, especially when the filtering system is not sufficiently effective. The specific nature of the melting process of nickel and cobalt alloys, carried out in vacuum induction furnaces,excludes the possibility of alloy refining and slag removal from the melt surface. Therefore, to improve the quality of castings (parts of aircraft engines, it is so important to evaluate the quality of ingots before charging them into the crucible of an induction furnace. It has been proved that one of the methods for rapid quality evaluation is an ATD analysis of the sample solidification process, where samples are taken from different areas of the master heat ingot. The evaluation is based on a set of parameters plotted on the graph of the dT/dt derivative curve during the last stage of the solidification process in a range from TEut to Tsol.

  18. Magnetic spherules from the soils near the slag dump of the Nizhniy Tagil metallurgical plant

    Directory of Open Access Journals (Sweden)

    A. B. Makarov

    2017-12-01

    Full Text Available Magnetic spherules, which are widespread in soils, can have different origins, but spherules with cosmic origin are the most studied. At that, functioning of numerous industrial enterprises of metallurgical profile, thermal power stations, and motor transport can be their origin. According to the data of previous researchers, spherical magnetic particles in soils can serve as an indicator for quantitative assessment of erosion-accumulative phenomena. The authors studied magnetic spherules, isolated from soil samples taken near the dump of blast furnace and metallurgical slags of a large Nizhny Tagil metallurgical plant located on the left bank of the Olkhovka river, functioning since 1949. The way the dump forms is by draining slag along the slope. Consequently, adjacent territories are exposed to a significant dust load, associated with increased concentrations of a number of heavy metals: chromium, iron, manganese, vanadium, copper and zinc. The study of magnetic spherules performed for samples of soils taken at a distance of 50 and 100 m to the west of the dump showed that the content of magnetic fraction in them was 15.1 and 11.7% respectively, of the mineral part of the samples. The authors studied magnetic spherules on a scanning microscope JEOL JSM 6390LV, an at that provide their morphology and the chemical composition of magnetic spherules (18 analyzes and aggregates on their surface (5 analyzes. Based on the presence of characteristic impurity elements, there are the following varieties: zinc, manganese, vanadium, determined by the peculiarities of metallurgical processes. Low concentrations of spherules in soils do not allow considering them as a significant source of pollution of natural environment, only a slight increase in the content of heavy metals characteristic for them is possible.

  19. Caracterização química de resíduos da indústria metalúrgica para fins de uso agrícolaChemical characterization of residues of the metallurgic industry for agricultural use

    OpenAIRE

    Montanari, Rafael; Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP; Marques Júnior, José; Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP; Campos, Milton César Costa; Universidade Federal Rural de Pernambuco - UFRPE; Souza, Zigomar Menezes de; Universidade Estadual de Campinas - UNICAMP

    2009-01-01

    Os órgãos de licenciamento ambiental têm se preocupado de modo especial com os impactos negativos da aplicação de resíduos industriais no meio ambiente. Dentro desse contexto, realizou-se este trabalho, com o objetivo de se estudar os produtos: escória do forno cubilô (EFC), e resíduos de ciclone do sistema de areia (CSA) e do ciclone dos desmoldadores (CD), originados de uma indústria metalúrgica, quanto a sua viabilidade de utilização para fins agrícolas. Esse estudo foi motivado pela preoc...

  20. The heavy metals in the muscle of some imported frozen fish in ...

    African Journals Online (AJOL)

    The heavy metal levels in the edible muscles of eight species of imported frozen fishes in four major markets in Ibadan were examined. The species examined were Ethmalosa harengus, Micromesistius poutassou, Sardinella eba, Trachurus trachurus, Scomber scombrus, Scomberomorous tritor, Pseudotololithus elongatus ...

  1. IOLOGICAL IMPORTANCE AND TOXICITY OF HEAVY METALS FOR BIOTA OF FRESHWATER BODIES (REVIEW

    Directory of Open Access Journals (Sweden)

    I. Hrytsyniak

    2014-06-01

    Full Text Available Purpose. To investigate the sources of scientific information on biological functions of heavy metals (Fe, Zn, Mn, Cu, Ni, Co, Pb, Cd and their negative effect on biota of fresh water bodies. Findings. A review of works of a variety of scientists showed that the majority of the studied heavy metals (Fe, Zn, Mn, Cum and Co played an important role in vital functions of freshwater organisms. The significance of other studied heavy metals (Ni, Pb, and Cd is probable or unknown. Besides biological importance, we also know about toxicity of heavy metals – a group of mineral polluting substances, which are the most distributed and dangerous for biota. Their negative effect includes drastic deterioration of conditions for existence of the majority of aquatic organisms, some species disappear, others reduce their number, components of trophic chains are lost, links in ecosystems become broken, and productivity of biocenoses decreases. Practical value. An array of generalized information will be useful for scientists who investigate freshwater ecosystems and effect of toxicants on them, in particular heavy metals.

  2. Key Lake Mining Corporation metallurgical complex

    International Nuclear Information System (INIS)

    Lendrum, F.C.

    1984-02-01

    The Key Lake uranium mine is located in Saskatchewan, 550 km northeast of Saskatoon. It began operations in 1983, and is licensed and regulated by both Saskatchewan government agencies and the Canadian Atomic Energy Control Board. This report examines the metallurgical processes used at the mill and discusses the spills that occurred in the first four months the mine was in operation. It finds that all spills of an acidic nature in the mill were small amounts in the CCD or solution pretreatment sections. Contingency procedures are in place and sumps are capable of handling spills. The only major change in design contemplated will be converting the secondary crushing from the use of an impact crusher to the use of a semi-autogeneous grinding mill. The monitoring program set out by the AECB and Saskatchewan Environment is thorough. It monitors effluents and water pathways, and includes aquatic biota and sediments. Air monitoring is also required by Saskatchewan Environment

  3. Centrifugal Casting Features/Metallurgical Characterization of Aluminum Alloys

    International Nuclear Information System (INIS)

    Chirita, G.; Soares, D.; Cruz, D.; Silva, F. S.; Stefanescu, I.

    2008-01-01

    This paper deals with the study of centrifugal effects on aluminium castings under high G values. Most of the studies in this domain (FGMs obtained by centrifugal casting) deal with functionally graded composites reinforced with a solid phase such as silicon particles or others. However, in this study it will be shown that unreinforced aluminium alloys may be significantly influenced by the centrifugal effect and that functionally graded castings are also obtained. It has been observed that the centrifugal effect may increase in some alloys, depending on the relative position in the castings, the rupture strength by approx. 50%, and rupture strain by about 300%, as compared to the gravity casting technique. The Young's modulus may also increase by about 20%. It has also been reported that in vertical centrifugal castings there are mainly three aspects that affect the components thus obtained, namely: fluid dynamics; vibration (inherent to the system); and centrifugal force. These features have a different effect on the castings depending on the aluminium alloy. In this paper, an analysis of the most important effects of the centrifugal casting process on metallurgical features is conducted. A solidification characterization at several points along the mould will be made in order to have an accurate idea of both the fluid dynamics inside the mould during the casting and the solidification behavior in different parts of the component. These two analyses will be related to the metallurgical properties (phase distribution; SDAS; eutectic silicon content and shape, pores density and shape) along the component and mainly along the direction of the centrifugal pressure. A comparison between castings obtained by both centrifugal casting technique and gravity casting technique is made for reference (gravity casting)

  4. Effect of metallurgical variables on void swelling

    International Nuclear Information System (INIS)

    Johnston, W.G.; Lauritzen, T.; Rosolowski, J.H.; Turkalo, A.M.

    1976-01-01

    The mechanism of void swelling is reviewed briefly and the anticipated effects of metallurgical variables are described. Experimental results showing the effects of metallurgical variables are reviewed, most of the work being done by simulation methods employing charged particle bombardments to simulate reactor damage. Although the early emphasis was on structural variables such as grain size, cold work and precipitates to control swelling, it now seems that the practical reduction of swelling will be achieved by modifying alloy composition. Void swelling is strongly influenced by the relative amounts of Fe, Cr, and Ni in an alloy; the amount of swelling can be varied by three orders of magnitude by changing the relative amounts of the three elements in an austenitic ternary alloy. The effect of composition on swelling of a simple ferritic alloy will also be described. The swelling of a simple austenitic alloy of Fe, Cr, and Ni can be reduced by certain minor element additions. The most effective swelling inhibitors are Si, Ti, Zr, and Nb, and combinations of Si and Ti are synergetic. Swelling reductions of two orders of magnitude have been achieved with combined additions. Predictions of swelling in commercial solid solution alloys are made on the basis of the present knowledge of the effects of major composition and minor element additions. The predictions agree with experimental results. For more complex commercial alloys, predictions are made for the effects on swelling of heat treatments that cause changes in matrix composition. In some cases, heat treatment is expected to change the peak swelling by more than a factor of ten, and to shift the peak swelling temperature by almost 100 0 C. Sensitivity of swelling to detailed matrix composition places emphasis on the need for developing understanding of the stability of structure and local composition in an irradiation environment

  5. Fatores de risco para hipertensão arterial e diabete melito em trabalhadores de empresa metalúrgica e siderúrgica Risk factors for hypertension and diabetes mellitus in metallurgic and siderurgic company's workers

    Directory of Open Access Journals (Sweden)

    Maria Carmen Martinez

    2006-10-01

    Full Text Available OBJETIVO: Estudar os fatores associados à hipertensão arterial (HA e ao diabete melito (DM em trabalhadores de empresa metalúrgica e siderúrgica com unidades em São Paulo e Rio de Janeiro, mediante um modelo hierárquico de risco. MÉTODOS: Este é um estudo transversal. Foram obtidas informações sobre variáveis demográficas, ocupacionais, do estilo de vida, perfil lipídico, glicemia de jejum e pressão arterial de 3.777 empregados, e realizadas análise estatística descritiva e análise de regressão logística múltipla hierarquizada. RESULTADOS: A prevalência de HA foi de 24,7%, e a análise de regressão hierarquizada indicou que sexo masculino e idade acima de quarenta anos apresentaram risco estatisticamente significativo. Independentemente das características demográficas, trabalhar em metalurgia, estresse intenso no trabalho, sedentarismo, consumo de álcool, índice de massa corporal superior a 25, colesterol alterado e triglicérides alterados estiveram associados com a HA. A prevalência de DM foi de 11,5%, e a análise de regressão hierarquizada indicou que sexo masculino e idade acima de quarenta anos apresentaram risco estatisticamente significativo. Independentemente das características demográficas, as mesmas condições estiveram associadas com a DM. CONCLUSÃO: Os dados evidenciaram que o trabalhador acima de quarenta anos é uma prioridade para ações de intervenção que possam favorecer a prevenção dos dois agravos. Nessas ações, deve-se dar atenção especial à alimentação e à prática de exercícios físicos, que favoreceriam o controle da obesidade e da alteração do perfil lipídico.OBJECTIVE: To study the factors associated with arterial hypertension (AH and diabetes mellitus (DM in a metal and steel industry's workers with units in São Paulo and Rio de Janeiro, using a hierarchical risk model. METHODS: This is a cross-sectional study. We obtained information on demographic, occupational and

  6. Assessment of Four Heavy Metals Mercury, Lead, Copper and Cadmium Levels in Muscles of Import-ed Tilapia to Iran

    Directory of Open Access Journals (Sweden)

    Behsan Hemmatinezhad

    2017-04-01

    Full Text Available This study was conducted to determine the residues of mercury (Hg, lead (Pb, copper (Cu and cadmium (Cd in the imported tilapia fillets. Thirty random samples from imported tilapia fillets were collected from different markets in Isfahan City, central Iran. They were analyzed using Graphite Furnace Atomic Absorption Spectrometer (Perkin Elmer 800 for Pb, Cu, Cd and flow injection mercury system (Perkin Elmer 400 for Hg. Out of the 30 tested samples, concentration of Hg, Pb, Cu and Cd in the tilapia fillets samples as mean± standard deviation were 0.083±.016, 0.638±0.067, 0.521± 0.081 and 0.136 ± 0.025 mg/kg, respectively. Among these, amounts obtained for all metals except for lead were lower than the permissible level specified by WHO (P<1%. The Pb concentrations in all examined samples were higher than WHO standards. The continuous consumption of these contaminated fish regularly for long time may lead to health troubles.

  7. Metal and hydrogen catalysis in isotopic hydrogen exchange in some biologically important heterocyclic compounds

    International Nuclear Information System (INIS)

    Buncel, E.; Joly, H.A.; Jones, J.R.; Onyido, I.

    1989-01-01

    This study reports on the catalytic roles of metal and hydrogen ions in tritium exchange in some heterocyclic substrates which occur as residues in many biologically important molecules. We have found that detritiation of 1-methyl[2- 3 H]imidazole is inhibited by a number of metal ions. As well, inhibition of exchange rates was noted with Ag(I) and Cu(II) for [2- 3 H]thiazole and 1-methyl[8- 3 H]inosine, with Ag(I) for [2- 3 H]benzothiazole, and with Cu(II) for 1-methyl[8- 3 H]guanosine. A complete mechanistic description, which includes the various metal ion-coordinated species generated under the experimental conditions, is presented. The results demonstrate the reactivity order: protonated >> metal-coordinated >> neutral substrates. The differential catalytic effects of metal and hydrogen ions in these processes are discussed in terms of the extent of charge developed on the ligating heteroatom in the reaction intermediate. (author). 13 refs.; 1 fig

  8. The application of winning key metrics in a metallurgical firm

    Directory of Open Access Journals (Sweden)

    M. Mikušová

    2014-10-01

    Full Text Available This article is focused on creating a system of metrics and its application in a metallurgical firm. Its aim is to highlight the dangers associated with the creation and application of an effective system of metrics. Its objective is also to demonstrate the process (initial steps in the development of this system in the real family metallurgical firm. In the experimental part an example of causal links among key metrics in the chosen metallurgical firm is presented. Risks associated with the selection of appropriate metrics are presented for discussion.

  9. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.Y.

    1993-03-01

    During fourth quarter 1992, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded final Primary Drinking Water Standards (PDWS) and the Savannah River Site Flag 2 criteria during the quarter. The results for fourth quarter 1992 are fairly consistent with the rest of the year's data. Tetrachloroethylene exceeded the final PDWS in well AMB 4D only two of the four quarters; in the other three wells in which it was elevated, it was present at similar levels throughout the year. Trichloroethylene consistently exceeded its PDWS in wells AMB 4A, 4B, 4D, 5, and 7A during the year. Trichloroethylene was elevated in well AMB 6 only during third and fourth quarters and in well AMB 7 only during fourth quarter. Total alpha-emitting radium was above the final PDWS for total radium in well AMB 5 at similar levels throughout the year and exceeded the PDWS during one of the three quarters it was analyzed for (third quarter 1992) in well AMB 10B.

  10. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report

    International Nuclear Information System (INIS)

    Thompson, C.Y.

    1993-03-01

    During fourth quarter 1992, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded final Primary Drinking Water Standards (PDWS) and the Savannah River Site Flag 2 criteria during the quarter. The results for fourth quarter 1992 are fairly consistent with the rest of the year's data. Tetrachloroethylene exceeded the final PDWS in well AMB 4D only two of the four quarters; in the other three wells in which it was elevated, it was present at similar levels throughout the year. Trichloroethylene consistently exceeded its PDWS in wells AMB 4A, 4B, 4D, 5, and 7A during the year. Trichloroethylene was elevated in well AMB 6 only during third and fourth quarters and in well AMB 7 only during fourth quarter. Total alpha-emitting radium was above the final PDWS for total radium in well AMB 5 at similar levels throughout the year and exceeded the PDWS during one of the three quarters it was analyzed for (third quarter 1992) in well AMB 10B

  11. Characterisation of hydrocarbonaceous overlayers important in metal-catalysed selective hydrogenation reactions

    Science.gov (United States)

    Lennon, David; Warringham, Robbie; Guidi, Tatiana; Parker, Stewart F.

    2013-12-01

    The hydrogenation of alkynes to alkenes over supported metal catalysts is an important industrial process and it has been shown that hydrocarbonaceous overlayers are important in controlling selectivity profiles of metal-catalysed hydrogenation reactions. As a model system, we have selected propyne hydrogenation over a commercial Pd(5%)/Al2O3 catalyst. Inelastic neutron scattering studies show that the C-H stretching mode ranges from 2850 to 3063 cm-1, indicating the mostly aliphatic nature of the overlayer and this is supported by the quantification of the carbon and hydrogen on the surface. There is also a population of strongly hydrogen-bonded hydroxyls, their presence would indicate that the overlayer probably contains some oxygen functionality. There is little evidence for any olefinic or aromatic species. This is distinctly different from the hydrogen-poor overlayers that are deposited on Ni/Al2O3 catalysts during methane reforming.

  12. Sustainable cost reduction by lean management in metallurgical processes

    Directory of Open Access Journals (Sweden)

    A. V. Todorut

    2016-10-01

    Full Text Available This paper focuses on the need for sustainable cost reduction in the metallurgical industry by applying Lean Management (LM tools and concepts in metallurgical production processes leading to increased competitiveness of corporations in a global market. The paper highlights that Lean Management is a novel way of thinking, adapting to change, reducing waste and continuous improvement, leading to sustainable development of companies in the metallurgical industry. The authors outline the main Lean Management instruments based on recent scientific research and include a comparative analysis of other tools, such as Sort, Straighten, Shine, Standardize, Sustain (5S, Visual Management (VM, Kaizen, Total Productive Maintenance (TPM, Single-Minute Exchange of Dies (SMED, leading to a critical appraisal of their application in the metallurgical industry.

  13. Soft restructuring process in metallurgical enterprises in Poland

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2015-10-01

    Full Text Available This article presents the range and outcomes of soft restructuring in metallurgical enterprises in Poland. The term ‘soft restructuring’ applies to changes in metallurgical enterprises’ employment policy during the period of political transformation in Poland. Steelworks performance under the market economy conditions demanded introducing changes in staff resources. Changes referred both to the staff structure as well as employees’ skills and gradual engaging of the staff in building the steelworks’ competitive advantage.

  14. Mercury distribution in an abandoned metallurgical plant

    Directory of Open Access Journals (Sweden)

    Millán R.

    2013-04-01

    Full Text Available The aim of the work is to evaluate the spatial distribution of Hg in the soil-plant system within an area where intense activity of Hg was dominant over a long period. An abandoned metallurgical plant from the 17th-18th centuries was chosen as the study area. It is situated in Almadenejos within the Almadén mining district (Spain that constitutes the largest and most unusual concentration of mercury in the world and has provided a third of the entire world production of mercury (Hg. Nowadays, this study area is covered with cinnabar mine tailings and village habitants use it for livestock. The area has elevated Hg concentrations of natural origin and from human activities. Soil parameters are similar throughout the study area; however, data reveal high variability in total and available Hg concentrations in soils, making it difficult to establish a tendency. Marrubium vulgare L.has been studied due to its high presence in the field plot, and there is no evidence of phenological toxicity. Furthermore, in spite of elevated Hg concentrations, a good biological activity is tested in the soil samples. All these characteristics, spatial variation, high Hg concentration, good biological activity, enhance the peculiarity of the study area for studies involving Hg.

  15. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report: Third quarter 1993

    International Nuclear Information System (INIS)

    1993-12-01

    During third quarter 1993, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards; and aluminum, iron, lead, manganese, pH, and total organic halogens exceeded the Savannah River Site Flag 2 criteria in one or more of the wells. Groundwater flow direction and rate in the water-table unit were similar to previous quarters

  16. Explosion bonding of dissimilar materials for fabricating APS front end components: Analysis of metallurgical and mechanical properties and UHV applications

    International Nuclear Information System (INIS)

    Li, Yuheng; Shu, Deming; Kuzay, T.M.

    1994-01-01

    The front end beamline section contains photon shutters and fixed masks. These components are made of OFHC copper and GlidCOP AL-15. Stainless steels (304 or 316) are also used for connecting photon shutters and fixed masks to other components that operate in the ultrahigh vacuum system. All these dissimilar materials need to be joined together. However, bonding these dissimilar materials is very difficult because of their different mechanical and thermal properties and incompatible metallurgical properties. Explosion bonding is a bonding method in which the controlled energy of a detonating explosive is used to create a metallurgical bond between two or more similar or dissimilar materials. No intermediate filler metal, for example, a brazing compound or soldering alloy, is needed to promote bonding, and no external heat need be applied. A study of the metallurgical and mechanical properties and YGV applications of GlidCop AL-15, OFHC copper, and 304 stainless steel explosion-bonded joints has been done. This report contains five parts: an ultrasonic examination of explosion-bonded joints and a standard setup; mechanical-property and thermal-cycle tests of GlidCop AL-15/304 stainless steel explosion-bonded joints; leak tests of a GlidCop AL-15/304 stainless steel explosion-bonded interfaces for UHV application; metallurgical examination of explosion-bonded interfaces and failure analysis, and discussion and conclusion

  17. Study of the Metallurgical Aspects of Steel Micro-Alloying by Titan

    Directory of Open Access Journals (Sweden)

    Kijac, J.

    2006-01-01

    Full Text Available The metal properties upgrading applying it’s alloying with the simultaneous limitation of the impurities represents a prospective possibility of the metallurgical production further development. The interaction of the alloying substance active element with oxygen in metal and adjacent multiphase environment occurs under the actual conditions. Present paper is oriented particularly to the thermodynamic aspects of deoxygenation by titan in process of production of micro alloyed low carbon steel in two plants (oxygen converter 1-OC1 and 2-OC2 with the different effect of micro-alloy exploitation. Analysis of the effect of the metallurgical factors on the titan smelting loss in micro-alloyed steel production points at the need to master the metal preparation for the alloying and especially has got the decisive effect upon the oxidizing ability and rate of the slag phase availability. When comparing the micro-alloying matter yield among the individual production units, disclosed have been better results obtained in plant OC 2. Confirmed has been the effect of the slag amount (average amount of 7,3 t at OC 1 and 5,83 t at OC 2 and its quality during the steel tapping as one among the most significant factors affecting the alloying process and which also represent its oxidizing potential.

  18. The two faces of coal : uncertainty the common prospect for metallurgical and thermal coal

    International Nuclear Information System (INIS)

    Zlotnikov, D.

    2010-01-01

    Although the methods of producing thermal and metallurgical coal are the same, metallurgical coal is destined to cross the world for steel manufacturing and thermal coal is destined for power plants close to where it was mined. This article discussed the factors influencing the price of these 2 coals. The production of thermal coal can remain steady during an economic crisis because coal-fired power plants generally provide low-cost-base-load electricity that remains stable during economic cycles. However, the demand for metallurgical coal is more volatile during an economic crisis because it is directly related to the demand for steel products in the construction and automotive industry, which are very sensitive to the state of the economy. There have been recent indications that Canada's export market for thermal coal is on the rise. In 2008, China became a net importer of coking coal. China's need for more coal to fuel its growing economy despite the global economic slowdown has meant that producers are diverting excess supply from European markets to China. Higher-end thermal coal offers low sulphur content and higher energy content, both desirable traits for power utilities facing strict emissions control. In addition to having huge reserves of very high-quality coal that is becoming increasingly important to China, Canada has the advantage of having the available transportation capacity in its west coast terminals and on its rail network. 3 figs.

  19. DETERMINATION THE CONCENTRATION OF SOME METALS IN IMPORTED CANNED FOOD AND CHICKEN STOCK

    OpenAIRE

    M. A. AL-Rajhi

    2014-01-01

    This study was carried out to determine the level of same selected metals namely Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Se, Al and V in some imported canned foods and chicken stock purchased from the local market in Riyadh, Saudi Arabia. The measurements were performed using inductively coupled plasma-optical emission Spectrometer (SPECTRO) analytical instruments. The result showed that the average concentration of the elements was 0.0007 for Cu, 0.0197 for Fe, 0.0029 for Mn, 0.0018 for N...

  20. Radiometric monitoring of contaminated scrap metals imported in Italy. Technical and regulatory features

    International Nuclear Information System (INIS)

    Dobici, F.; Piermattei, S.; Susanna, A.

    1996-01-01

    During these last ten years there have been occasional reports of mishaps from trafficking of contaminated scraps or containing radioactive sources. Recently an increase of events indicated that the problem becomes more important as to generate possible consequences, from a radiation protection standpoint, for workers and general public. Following the detection of contaminated metal scraps in some recycling industries and in some consignments entering the Italian borders, the competent Authorities laid down rules to put the matter under control. In this paper technical and regulatory features are discussed. (author)

  1. The importance of metal based redox reactions in controlling the biodistributions of diagnostic and therapeutic radiopharmaceuticals

    International Nuclear Information System (INIS)

    Deutsch, E.A.

    1990-01-01

    Many radiopharmaceuticals used for diagnosing and treating disease are formed by incorporating transition metal radionuclides (e.g., 62-Cu, 99m-Tc, 186-Re) into coordination complexes. After intravenous injection, such complexes can undergo in vivo redox reactions which strongly affect the biodistribution of the core radionuclide. Understanding and controlling these redox reactions is important to the design and development of new radiopharmaceuticals. These principles are illustrated by examples taken from the development of 99m-Tc and 62-Cu complexes as potential heart and brain perfusion imaging agents, and the development of 186-Re complexes a therapeutic agents for palliation of the pain associated with metastatic bone cancer

  2. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    The paper reviews the role of sintered tantalum as volumetric efficient electrical capacitor. Powder characteristics and sintering aspects are discussed. The role of impurities in influencing the electrical properties has been described. Today's driving force behind the Ta market is the use of surface mounted versions known as ...

  3. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    ... and sintering aspects are discussed. The role of impurities in influencing the electrical properties has been described. Today's driving force behind the Ta market is the use of surface mounted versions known as chip types, for applications requiring a wide range of operational temperature, such as automotive electronics.

  4. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    Unknown

    morphology of the tantalum powder and the work on leakage has been done on the oxide film. The emphasis has been on the improvement of the dielectric film to lower the leakage and increase the breakdown voltage. Most finished powders made by the sodium reduction process have a complex nodular morphology.

  5. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    Unknown

    Next, the anodized pellet is impregnated with manganese nitrate which is then thermally decomposed to leave or deposit semiconducting manganese dioxide on ... In order to improve physical properties of powder, they are generally agglomerated. But this heat treatment causes the surface oxygen to dissolve in the bulk.

  6. Important parameters for optimized metal nanoparticles-aided electromagnetic field (EMF) effect on cancer.

    Science.gov (United States)

    Ochoo, Lawrence; Migwi, Charles; Okumu, John

    2018-01-01

    A number of experimental research findings for the metal nanoparticles (NPs)-mediated EMF photothermal therapy of cancer cells show an intriguing trend of the NPs' size-dependent efficacy. This is a phenomenon we find to trend with the light absorption bandwidth behavior (full width at half maximum) of the NPs and the accompanying electric field enhancement. We find that the nanoparticle sizes that have been reported to produce the optimized effect on cancer cells are of minimum absorption bandwidth and optimized electric field magnitude. While the death of cancer cells under the NPs-aided EMF effect has in the past attracted varied interpretations, either as a thermal or non-thermal effect, photothermal effect has gained a wide acceptance due to the exhibited hyperthermia. However, the exhibited trend of the NPs' size-dependent efficacy is beginning to feature as a possible manifestation of other overlooked underlying or synergistic phenomenal conditions. We present a theoretical model and analysis which reveal that the contribution and efficacy of the metal NPs in the destruction of cancer depend partly but significantly on the accompanying electric field intensity enhancement factor and partly on their absorption cross-section. This paper finds that, other than the expected hyperthermia, the metal NPs' sizes for the optimized therapy on cancer cells seem to fulfill other synergistic conditions which need to come to the fore. We find interplay between electric field and thermal effects as independent energy channels where balancing may be important for the optimized EMF effect, in the ratio of about 5:1. The required balancing depends on the absorption bandwidth and absorption cross-section of the NPs, the frequency of EMF used and the relative permittivity of the cancer cells. The NPs' size-dependent efficacy decreases away from the NPs' size of minimum absorption bandwidth, which is around 20 nm for Au NPs or other shapes of equivalent surface area

  7. Metallurgical test work to support development of the Kintyre Project

    International Nuclear Information System (INIS)

    Maley, M.; Ring, R.; Paulsen, E.; Maxton, D.

    2014-01-01

    The Kintyre uranium deposit is located in the Pilbara region of Western Australia and is jointly owned by Cameco and Mitsubishi. The current indicated resource estimate is approximately 55 million pounds of U 3 O 8 equivalent [~21,000 t U] at an average grade of 0.58% [0.49% U]. Due to the high levels of carbonate minerals in the deposit, alkaline leaching was strongly considered as an option to the usually preferred acid route. Following a detailed assessment, the acid option was chosen, with the preferred flowsheet involving an acid leach, followed by solvent extraction and precipitation. As part of the Kintyre metallurgical investigations, ANSTO Minerals performed an extensive work program, examining numerous aspects of the proposed flowsheet. This included a leach optimisation program, followed by a study determining the effects of sample variability in leaching. Settling, filtration and rheology work on slurries and tailings was performed, as well as testwork to determine the effect of neutralisation conditions on metal precipitation and radionuclide deportment. In addition, an extensive laboratory and solvent extraction mixer-settler mini-pilot plan campaign was performed to compare the performance of conventional ammonia/ammonium sulphate strip and the non-conventional strong acid strip (400 g/L H 2 SO 4 ) using leach liquor generated from Kintyre ore. The pilot plant involved two campaigns of three days continuous operation using each stripping system, with >99.5% uranium recovery achieved in each campaign. This paper will present an overview of the key results from the Kintyre leaching and neutralisation testwork undertaken at ANSTO Minerals, and will also outline the performance of the solvent extraction mini pilot plant. (author)

  8. Application of transformational roasting to the treatment of metallurgical wastes

    Science.gov (United States)

    Holloway, Preston Carl

    Transformational roasting involves the heating of a material along with specific additives to induce mineralogical changes in the starting material. By controlling the chemical composition, roasting atmosphere, temperature and time of reaction, the mineral transformations induced during roasting can be engineered to control the distribution of valuable or harmful metals and to produce new mineral assemblages that are more amenable to conventional methods of metals recovery or to environmentally safe disposal. However, to date, transformational roasting processes have only been applied to the recovery of a limited number of metals from a limited number of materials. A generalized procedure for the application of transformational roasting techniques to the treatment of new materials was proposed that utilized a combination of thermodynamic analysis, scoping tests, Design of Experiments (DOE) testing, mineralogical studies, process optimization and analysis of the deportment of minor elements to identify promising roasting systems for further study. This procedure was developed, tested and refined through the application of these techniques to four different industrial metallurgical wastes, including oil sands fly ash from Suncor in northern Alberta, zinc ferrite residue from Doe Run Peru, electric are furnace (EAF) dust from Altasteel's operations in Edmonton, Alberta, and copper-nickel-arsenic sulphide residue from Inco's refinery in Thompson, Manitoba. A large number of potential reagents were identified and tested for the latter three materials and transformational roasting was effectively used to induce mineral transformations during the roasting of these wastes which increased the solubility of valuable elements, decreased the solubility of major impurities, produced a differential solubility between valuable and harmful elements or controlled the volatilization of harmful elements. Comprehensive studies of these mineralogical transformations and the solubility

  9. Genetic basis and importance of metal resistant genes in bacteria for bioremediation of contaminated environments with toxic metal pollutants.

    Science.gov (United States)

    Das, Surajit; Dash, Hirak R; Chakraborty, Jaya

    2016-04-01

    Metal pollution is one of the most persistent and complex environmental issues, causing threat to the ecosystem and human health. On exposure to several toxic metals such as arsenic, cadmium, chromium, copper, lead, and mercury, several bacteria has evolved with many metal-resistant genes as a means of their adaptation. These genes can be further exploited for bioremediation of the metal-contaminated environments. Many operon-clustered metal-resistant genes such as cadB, chrA, copAB, pbrA, merA, and NiCoT have been reported in bacterial systems for cadmium, chromium, copper, lead, mercury, and nickel resistance and detoxification, respectively. The field of environmental bioremediation has been ameliorated by exploiting diverse bacterial detoxification genes. Genetic engineering integrated with bioremediation assists in manipulation of bacterial genome which can enhance toxic metal detoxification that is not usually performed by normal bacteria. These techniques include genetic engineering with single genes or operons, pathway construction, and alternations of the sequences of existing genes. However, numerous facets of bacterial novel metal-resistant genes are yet to be explored for application in microbial bioremediation practices. This review describes the role of bacteria and their adaptive mechanisms for toxic metal detoxification and restoration of contaminated sites.

  10. Leachability of protein and metals incorporated into aquatic invertebrates: are species and metals-exposure history important?

    Science.gov (United States)

    Meyer, J.S.; Suedkamp, M.J.; Morris, J.M.; Farag, A.M.

    2005-01-01

    To partially simulate conditions in fish intestinal tracts, we leached six groups of metals-contaminated invertebrates at pH 2 and pH 7, and analyzed the concentrations of four metals (Cd, Cu, Pb, and Zn) and total protein in the leachates. Four of the groups of invertebrates were benthic macroinvertebrates collected from metals-contaminated rivers (the Clark Fork River in Montana and the Coeur d’Alene River in Idaho, USA); the other two groups of invertebrates (one of which was exposed to metals in the laboratory) were laboratory-reared brine shrimp (Artemia sp.). Additionally, we fractionated the pH 2 leachates using size-exclusion chromatography (SEC). Protein content was 1.3 to 1.4× higher in Artemia than in the benthic macroinvertebrates, and leachability of metals and protein differed considerably among several of the groups of invertebrates. In SEC fractions of the pH 2 leachates from both groups of Artemia, Cu and protein co-eluted; however, Cu and protein did not co-elute in SEC fractions of the leachates from any of the benthic macroinvertebrate groups. Although none of the other three metals co-eluted with protein in any of the pH 2 leachates, one or more of the metals co-eluted with lower-molecular-weight molecules in the leachates from all of the groups of invertebrates. These results suggest fundamental differences in metal-binding properties and protein leachability among some invertebrates. Thus, different invertebrates and different histories of metals exposure might lead to different availability of metals and protein to predators.

  11. VLSI metallization

    CERN Document Server

    Einspruch, Norman G; Gildenblat, Gennady Sh

    1987-01-01

    VLSI Electronics Microstructure Science, Volume 15: VLSI Metallization discusses the various issues and problems related to VLSI metallization. It details the available solutions and presents emerging trends.This volume is comprised of 10 chapters. The two introductory chapters, Chapter 1 and 2 serve as general references for the electrical and metallurgical properties of thin conducting films. Subsequent chapters review the various aspects of VLSI metallization. The order of presentation has been chosen to follow the common processing sequence. In Chapter 3, some relevant metal deposition tec

  12. Energy-dissipation-model for metallurgical multi-phase-systems

    Energy Technology Data Exchange (ETDEWEB)

    Mavrommatis, K.T. [Rheinisch-Westfaelische Technische Hochschule Aachen, Aachen (Germany)

    1996-12-31

    Entropy production in real processes is directly associated with the dissipation of energy. Both are potential measures for the proceed of irreversible processes taking place in metallurgical systems. Many of these processes in multi-phase-systems could then be modelled on the basis of the energy-dissipation associated with. As this entity can often be estimated using very simple assumptions from first principles, the evolution of an overall measure of systems behaviour can be studied constructing an energy-dissipation -based model of the system. In this work a formulation of this concept, the Energy-Dissipation-Model (EDM), for metallurgical multi-phase-systems is given. Special examples are studied to illustrate the concept, and benefits as well as the range of validity are shown. This concept might be understood as complement to usual CFD-modelling of complex systems on a more abstract level but reproducing essential attributes of complex metallurgical systems. (author)

  13. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer

    International Nuclear Information System (INIS)

    Kazi, T.G.; Jalbani, N.; Arain, M.B.; Jamali, M.K.; Afridi, H.I.; Sarfraz, R.A.; Shah, A.Q.

    2009-01-01

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy

  14. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, T.G. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: tgkazi@yahoo.com; Jalbani, N. [PCSIR Laboratories Karachi (Pakistan)], E-mail: nusratjalbani_21@yahoo.com; Arain, M.B. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: bilal_KU2004@yahoo.com; Jamali, M.K. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: mkhanjamali@yahoo.com; Afridi, H.I. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: hassanimranafridi@yahoo.com; Sarfraz, R.A. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: rajaadilsarfraz@gmail.com; Shah, A.Q. [Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)], E-mail: aqshah07@yahoo.com

    2009-04-15

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy.

  15. Evaluation of Additively Manufactured Metals for Use in Oxygen Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — 1.     Objectives:Rigorously study metals produced by AM processes ignition and flammability hazards as compared to wrought metals of the comparable metallurgical...

  16. Explosion metal welding

    International Nuclear Information System (INIS)

    Popoff, A.A.

    1976-01-01

    Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community

  17. Safety performance indicators in the metallurgical industry using WEB programming

    Directory of Open Access Journals (Sweden)

    M. Cioca

    2017-01-01

    Full Text Available Sustainable development has a significant impact today in Romania and worldwide. In this context, risk assessment becomes mandatory for enterprises. This paper analyzes the situation of occupational risks in the metallurgical industry in the European Union, Romania, and the United States and highlights the main causes for work accidents in Romanian metallurgical industry. The analysis covers the period 2010 - 2016. The data collected from Romania is compared to the data related to the European Union and the United States. Moreover, the paper aims to present an occupational risk assessment tool, which is customizable for each area of activity. The last section of the paper discusses the research results and limitations.

  18. A metallurgical study of Nāga Bhasma

    Directory of Open Access Journals (Sweden)

    Dev Nath Singh Gautam

    2017-01-01

    Full Text Available Background: The metal Nāga (Lead is being used by Indians since ancient times. Its external and internal uses have been described in Caraka, Suśruta and other Ayurvedic Saṃhitā. According to most of the Rasa texts, Nāga Bhasma and its formulations are used in many diseases such as Prameha, Jvara, Gulma, Śukrameha etc. Objectives: In the present study, Nāga Bhasma was prepared by the traditional Puṭa method (TPM and by the electric muffle furnace Puṭa method (EMFPM and standardized using Metallographic studies. Doing so helps in the study of the microstructure of Nāga Bhasma and also helps in the identification of the metal particles along with the nature of compound formed during the Māraṇa (Bhasmīkaraṇa process. Setting and Design: Different samples from initial raw material to final product of Nāga Bhasma were collected during the pharmaceutical process (1st, 30th and 60th Puṭa from both methods i.e. TPM and EMFPM. Samples from both methods were studied using metallographic examination. Materials and Methods: The processing of the Nāga Bhasma (ṣaṣṭipuṭa was done according to Ānanda Kanda[9] Samples from the raw material i.e. Aśodhita Nāga (raw Lead and that processed after 1st, 30th and 60th Puṭa from both methods i.e. traditional Puṭa method (using heat from burning of cow dung cakes and electric muffle furnace Puṭa method were taken. They were mounted on self hardening acrylic base. After careful polishing to obtain scratch free surface of product, they were used for metallurgical study. Conclusion: This study shows that traditional Puṭa method may be better than electric muffle furnace Puṭa method because of more homogeneous distribution of Lead sulphide in the Nāga Bhasma which is prepared by traditional method.

  19. Contamination with heavy metals and bacteria in some local and imported fish and fish products

    International Nuclear Information System (INIS)

    Salem, S.B.; El-Dashlout, A.A.; El-Schiwee, M.A.; EL-Shourbagy, G.A.; Ibrahim, R.E.

    2004-01-01

    Some local and imported fish and fish products sold in retail markets of three cities at Sharkia Governorate, Egypt, were examined against heavy metals contamination (i.e. Pb, Cd and Hg) and the presence of some specific groups of bacteria. The results showed that concentrations of Pb in fresh and frozen fish, salted and smoked fish and canned fish samples were lower than the permissible limits recommended by the Egyptian Organization 1993 (1.0 mg/kg). On the other hand, all the tested fish and fish products of collected samples showed levels of Cd (0.29-0.41 mg/kg) higher than the permissible limit (0.10 mg/kg) recommended by the Egyptian Organization. Such limits should be re-considered because the limit determined by WHO (1992) was 0.5 mg/kg. Mercury level in fresh mullet was equal or lower (0.46-0.50 mg/kg) than the limit of Egyptian Organization (0.50 mg/kg) while other fresh and frozen fish, salted and smoked fish samples had higher Hg than the allowance. In most cases, imported canned products of sardine, mackerel and tuna had higher Pb, Cd and Hg concentrations than that found in the local ones. Among fresh fish samples, such as mackarona, contained the highest total bacterial count, while mullet was the lowest. Considering salted and smoked fish, heavy salted mullet had the highest total bacterial count, while the lowest number was recorded in salted sardine. Smoked herring showed lowest total bacterial count than salted samples. Generally, no correlation was observed between fish species or consumption place and the contamination with heavy metals and bacteria

  20. Metallurgical and mechanical examinations of steel–copper joints arc welded using bronze and nickel-base superalloy filler materials

    International Nuclear Information System (INIS)

    Velu, M.; Bhat, Sunil

    2013-01-01

    Highlights: ► Optical and scanning electron microscopy show defect free weld interfaces. ► Energy dispersive spectroscopy shows low dilution level of the weld by Fe. ► XRD studies show no brittle intermetallic phases in the weld interfaces. ► Weld interfaces did not fail during tensile, transverse bending and impact tests. ► The joint exhibits superior strength properties than that of bronze filler. - Abstract: The paper presents metallurgical and mechanical examinations of joints between dissimilar metals viz. copper (UNSC11000) and alloy steel (En31) obtained by Shielded Metal Arc Welding (SMAW) using two different filler materials, bronze and nickel-base super alloy. The weld bead of the joint with bronze-filler displayed porosity, while that with nickel-filler did not. In tension tests, the weldments with bronze-filler fractured in the centre of the weld, while those with nickel-filler fractured in the heat affected zone (HAZ) of copper. Since the latter exhibited higher strength than the former, all the major tests were undertaken over the joints with nickel-filler alone. Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) indicated corrugated weld interfaces and favorable elemental diffusions across them. X-ray diffraction (XRD) studies around the weld interfaces did not reveal any detrimental intermetallic compounds. Transverse bending tests showed that flexural strengths of the weldments were higher than the tensile strengths. Transverse side bend tests confirmed good ductility of the joints. Shear strength of the weld-interface (Cu–Ni or Ni–steel) was higher than the yield strength of weaker metal. Microhardness and Charpy impact values were measured at all the important zones across the weldment

  1. Toxicity of heavy metals to fish: an important consideration for sucessful aquaculture

    OpenAIRE

    Nnaji, J.C.; Okoye, F.C.

    2007-01-01

    Heavy metals are toxic to man, animals and plants once safe limits are exceeded. Then ability to bio accumulate in plant and animal tissues makes them particularly hazardous. Heavy metals are toxic to all aquatic biota and cause high mortality of fish larva, fry, fingerling and adult fish. They accumulate in the gills, heart, liver, kidneys, brain, bones and muscles of fish. The physico-chemical forms of heavy metals determine their mobility, availability and toxicity to fish. These metals en...

  2. Evaluation of trace metals in tobacco of local and imported cigarette brands used in Pakistan by spectrophotometer through microwave digestion.

    Science.gov (United States)

    Ajab, Huma; Yasmeen, Sadia; Yaqub, Asim; Ajab, Zainab; Junaid, Muhammad; Siddique, Maria; Farooq, Robina; Malik, Salman Akbar

    2008-10-01

    Uncontrolled exposure of active and passive smokers to trace metals causes increase in health risks. The primary objective of this study was to determine whether local and imported cigarette brands used in Pakistan, have elevated levels of metals or not. Six metals manganese (Mn), cobalt (Co), copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) were determined in tobacco of twenty cigarette brands (local and imported) used in Pakistan by flame atomic absorption Spectrophotometry. To overcome contamination chances and for complete digestion of analytes a microwave digester was used. The analytical results showed highest concentration of Mn (84.78 microg/g dry weight), Cd (0.525 microg/g dry weight) and Zn (14.34 microg/g dry weight) metals in imported brands in relation to counterparts from the local brands. Certain elevated levels were observed for Co (3.344 microg/g dry weight), Pb (14.16 microg/g dry weight) and Cu (7.889 microg/g dry weight) metals in local brands. The inter-metal relationships in the tobacco of local and imported cigarette brands showed some integrated variation in the selected metal levels. In view of health risk associated with the above metals, there should be a strict quality control over monitoring of heavy metals during growing, processing and smoking of tobacco. Therefore, it is prudent to minimize exposure to toxic substances whenever possible because smoking and exposure to cigarette smoke is a confounder to be taken into account when carrying out epidemiological studies on human exposure to metals.

  3. Powder metallurgical high performance materials. Proceedings. Volume 2: P/M hard materials

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

  4. Metallurgical viewpoints on the brittleness of beryllium

    International Nuclear Information System (INIS)

    Lagerberg, G.

    1960-02-01

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed

  5. Metallurgical viewpoints on the brittleness of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Lagerberg, G.

    1960-02-15

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed.

  6. Metallurgical and mechanical characterization of mild steel-mild ...

    Indian Academy of Sciences (India)

    679–686. c Indian Academy of Sciences. Metallurgical and mechanical characterization of mild steel-mild steel joint formed by microwave hybrid heating process. AMIT BANSAL1,∗, APURBBA KUMAR SHARMA1 and. SHANTANU DAS2. 1Mechanical and Industrial Engineering Department, Indian Institute of Technology.

  7. The R85m President Brand joint metallurgical complex

    International Nuclear Information System (INIS)

    Payne, Adam.

    1977-01-01

    The uranium plant at President Brand, which was built in 1971 and opened last year, is now being extended. The plant forms only part of the extensive joint metallurgical complex being developed by Anglo American Corp. in the Free State, costing a total R85million. This article examines technical details of the recovery processes involved

  8. Cost estimation and management over the life cycle of metallurgical ...

    African Journals Online (AJOL)

    This study investigates whether all expected costs over the life cycle of metallurgical research projects are included in initial, normal and fi nal cost estimates, and whether these costs are managed throughout a project's life cycle since there is not enough emphasis on the accurate estimation of costs and their management ...

  9. Options of utilizing steelmaking dust in a non-metallurgical industry

    Directory of Open Access Journals (Sweden)

    T. Lis

    2012-04-01

    Full Text Available Recycling of by-products of the steelmaking process in electric arc (EAF furnaces is an important activity from the perspective of environmental protection as well as the steelmaking industry itself. This article is a discussion concerning the selected research results in terms of utilisation of steelmaking dusts containing 4 - 12 % of zinc in manufacture of cement bricks, ceramic construction materials as well as colored glass products. The research conducted has implied that using steelmaking dusts in non-metallurgical industries is both possible and reasonable.

  10. Selection of human capital in metallurgical companies using information technology (IT

    Directory of Open Access Journals (Sweden)

    I. Iancu

    2013-10-01

    Full Text Available Personnel selection is a process that takes place in a company in order to have better business performance and competitive advantage. Nowadays, companies have realized the importance of human capital as a necessity for survival in today’s competitive market. There are several methods for selecting staff, but this paper seeks to demonstrate that this selection can be done with the help of an expert system. Metallurgical companies face even greater challenges for managing personnel selection. This research will discover and test the key elements of management personnel selection and implementation of an expert system.

  11. Metal toxicity characterization factors for marine ecosystems: considering the importance of the estuary for freshwater emissions

    DEFF Research Database (Denmark)

    Dong, Yan; Rosenbaum, Ralph K.; Hauschild, Michael Zwicky

    2017-01-01

    for metal emissions to freshwater and coastal seawater, respectively. The new CFs were applied to calculate endpoint impact scores for the same amount of metal emission to each compartment, to compare the relative ecotoxicity damages in freshwater and marine ecosystems in LCA. Site-dependent marine CFs...... as the best one. Endpoint marine and freshwater metals CFs were developed to calculate endpoint ecotoxicity impact scores. Marine ecotoxicity CFs are 1.5 orders of magnitude lower for emission to freshwater than for emission to seawater for Cr, Cu, and Pb, due to notable removal fractions both in freshwater...... CFs for emission to seawater are 1–4 orders of magnitude lower except for Pb. The new site-generic marine CFs for emission to freshwater lie within two orders of magnitude difference from USES-LCA 2.0 CFs. The comparative contribution share analysis shows a poor agreement of metal toxicity ranking...

  12. The first metallurgical tests on plutonium

    International Nuclear Information System (INIS)

    Grison, E.; Abramson, R.; Anselin, F.; Monti, H.

    1958-01-01

    Metallic plutonium was first prepared in France in January 1956, as soon as we had access to quantities of the order of several grams of plutonium, which had been extracted from the rods of the pile EL2 at Saclay. Since up to the present this reactor, of thermal power 2 000 kW, has been our only source of plutonium, we have so far only worked on experimental quantities sufficient for the basic tests but not for tests on a scale of possible applications. It is this work, carried out during this phase of preliminary research, which is described below. With the starting up of the plutonium extraction plant at Marcoule, where the reactor G1 has been operating at power for more than a year, we shall go on next to a another order of magnitude which will allow the manufacture and experimentation of prototype fuel elements. (author) [fr

  13. Ionising radiation metrology for the metallurgical industry

    Directory of Open Access Journals (Sweden)

    García-Toraño E.

    2014-01-01

    Full Text Available Every year millions tons of steel are produced worldwide from recycled scrap loads. Although the detection systems in the steelworks prevent most orphan radioactive sources from entering the furnace, there is still the possibility of accidentally melting a radioactive source. The MetroMetal project, carried out in the frame of the European Metrology Research Programme (EMRP, addresses this problem by studying the existing measurement systems, developing sets of reference sources in various matrices (cast steel, slag, fume dust and proposing new detection instruments. This paper presents the key lines of the project and describes the preparation of radioactive sources as well as the intercomparison exercises used to test the calibration and correction methods proposed within the project.

  14. On dithiothreitol (DTT) as a measure of oxidative potential for ambient particles: evidence for the importance of soluble transition metals.

    Science.gov (United States)

    Charrier, J G; Anastasio, C

    2012-05-03

    The rate of consumption of dithiothreitol (DTT) is increasingly used to measure the oxidative potential of particulate matter (PM), which has been linked to the adverse health effects of PM. While several quinones are known to be very reactive in the DTT assay, it is unclear what other chemical species might contribute to the loss of DTT in PM extracts. To address this question, we quantify the rate of DTT loss from individual redox-active species that are common in ambient particulate matter. While most past research has indicated that the DTT assay is not sensitive to metals, our results show that seven out of the ten transition metals tested do oxidize DTT, as do three out of the five quinones tested. While metals are less efficient at oxidizing DTT compared to the most reactive quinones, concentrations of soluble transition metals in fine particulate matter are generally much higher than those of quinones. The net result is that metals appear to dominate the DTT response for typical ambient PM(2.5) samples. Based on particulate concentrations of quinones and soluble metals from the literature, and our measured DTT responses for these species, we estimate that for typical PM(2.5) samples approximately 80 % of DTT loss is from transition metals (especially copper and manganese), while quinones account for approximately 20 %. We find a similar result for DTT loss measured in a small set of PM(2.5) samples from the San Joaquin Valley of California. Because of the important contribution from metals, we also tested how the DTT assay is affected by EDTA, a chelator that is sometimes used in the assay. EDTA significantly suppresses the response from both metals and quinones; we therefore recommend that EDTA should not be included in the DTT assay.

  15. Method of purifying metallurgical grade silicon employing reduced pressure atmospheric control

    Science.gov (United States)

    Ingle, W. M.; Thompson, S. W.; Chaney, R. E. (Inventor)

    1979-01-01

    A method in which a quartz tube is charged with chunks of metallurgical grade silicon and/or a mixture of such chunks and high purity quartz sand, and impurities from a class including aluminum, boron, as well as certain transition metals including nickel, iron, and manganese is described. The tube is then evacuated and heated to a temperature within a range of 800 C to 1400 C. A stream of gas comprising a reactant, such as silicon tetrafluoride, is continuously delivered at low pressures through the charge for causing a metathetical reaction of impurities of the silicon and the reactant to occur for forming a volatile halide and leaving a residue of silicon of an improved purity. The reactant which included carbon monoxide gas and impurities such as iron and nickel react to form volatile carbonyls.

  16. Leaching of nickel and copper from soil contaminated by metallurgical dust.

    Science.gov (United States)

    Barcan, Valery

    2002-04-01

    The paper presents the results of the laboratory percolation experiment simulated soil contamination by emissions from a Ni-Cu smelter. Humus (Ao horizon) columns were transferred to lysimeters from an illuvial, humic, ferriferous forest podzol site. Fine metallurgical dust containing Ni and Cu was layered on the columns and irrigated with sulphuric acid solutions at pH 3, 4, 5, and 6. Irrigation for 19 months indicated that the leaching of metals down the humus column was greatest at pH 6. Calculations indicated that it would take 160-270 years for complete leaching of Ni from the Ao layer, and 100-200 years for Cu, depending on the dust composition. Natural decontamination of affected soils will take centuries.

  17. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Second quarter 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    During second quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Three parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards. Total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria in two of the wells. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to previous quarters. During second quarter 1994, SRS received SCDHEC approval for five point-of-compliance wells and two plume definition wells near the Met Lab HWMF. Field work has begun on this project.

  18. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. First quarter 1995

    International Nuclear Information System (INIS)

    1995-06-01

    During first quarter 1995, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, field measurements, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Total organic halogens exceeded its Savannah River Site (SRS) Flag 2 criterion during first quarter 1995 as in fourth quarter 1994. Aluminum, iron, and manganese, which were not analyzed for during fourth quarter 1994, exceeded the Flag 2 criteria in at least two wells each during first quarter 1995. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting the determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to previous quarters

  19. The Importance of Transition Metals in the Expanding Network of Microbial Metabolism in the Archean Eon

    Science.gov (United States)

    Moore, E. K.; Jelen, B. I.; Giovannelli, D.; Prabhu, A.; Raanan, H.; Falkowski, P. G.

    2017-12-01

    Deep time changes in Earth surface redox conditions, particularly due to global oxygenation, has impacted the availability of different metals and substrates that are central in biology. Oxidoreductase proteins are molecular nanomachines responsible for all biological electron transfer processes across the tree of life. These enzymes largely contain transition metals in their active sites. Microbial metabolic pathways form a global network of electron transfer, which expanded throughout the Archean eon. Older metabolisms (sulfur reduction, methanogenesis, anoxygenic photosynthesis) accessed negative redox potentials, while later evolving metabolisms (oxygenic photosynthesis, nitrification/denitrification, aerobic respiration) accessed positive redox potentials. The incorporation of different transition metals facilitated biological innovation and the expansion of the network of microbial metabolism. Network analysis was used to examine the connections between microbial taxa, metabolic pathways, crucial metallocofactors, and substrates in deep time by incorporating biosignatures preserved in the geologic record. Nitrogen fixation and aerobic respiration have the highest level of betweenness among metabolisms in the network, indicating that the oldest metabolisms are not the most central. Fe has by far the highest betweenness among metals. Clustering analysis largely separates High Metal Bacteria (HMB), Low Metal Bacteria (LMB), and Archaea showing that simple un-weighted links between taxa, metabolism, and metals have phylogenetic relevance. On average HMB have the highest betweenness among taxa, followed by Archaea and LMB. There is a correlation between the number of metallocofactors and metabolic pathways in representative bacterial taxa, but Archaea do not follow this trend. In many cases older and more recently evolved metabolisms were clustered together supporting previous findings that proliferation of metabolic pathways is not necessarily chronological.

  20. LWR surveillance dosimetry improvement program: PSF metallurgical blind test results

    International Nuclear Information System (INIS)

    Kam, F.B.K.; Maerker, R.E.; Stallmann, F.W.

    1984-01-01

    The metallurgical irradiation experiment at the Oak Ridge Research Reactor Poolside Facility (ORR-PSF) was designed as a benchmark to test the accuracy of radiation embrittlement predictions in the pressure vessel wall of light water reactors on the basis of results from surveillance capsules. The PSF metallurgical Blind Test is concerned with the simulated surveillance capsule (SSC) and the simulated pressure vessel capsule (SPVC). The data from the ORR-PSF benchmark experiment are the basis for comparison with the predictions made by participants of the metallurgical ''Blind Test''. The Blind Test required the participants to predict the embrittlement of the irradiated specimen based only on dosimetry and metallurgical data from the SSC1 capsule. This exercise included both the prediction of damage fluence and the prediction of embrittlement based on the predicted fluence. A variety of prediction methodologies was used by the participants. No glaring biases or other deficiencies were found, but neither were any of the methods clearly superior to the others. Closer analysis shows a rather complex and poorly understood relation between fluence and material damage. Many prediction formulas can give an adequate approximation, but further improvement of the prediction methodology is unlikely at this time given the many unknown factors. Instead, attention should be focused on determining realistic uncertainties for the predicted material changes. The Blind Test comparisons provide some clues for the size of these uncertainties. In particular, higher uncertainties must be assigned to materials whose chemical composition lies outside the data set for which the prediction formula was obtained. 16 references, 14 figures, 5 tables

  1. Thermo-ecological cost (TEC evaluation of metallurgical processes

    Directory of Open Access Journals (Sweden)

    W. Stanek

    2015-01-01

    Full Text Available Metallurgy represents a complex production system of fuel and mineral non-renewable resources transformation. The effectiveness of resource management in metallurgical chains depends on the applied ore grade and on the irreversibility of components of the system. TEC can be applied to measure the influence of metallurgy on the depletion of natural resources. The paper discusses the possibility of application of TEC in metallurgy and presents illustrative example concerning blast-furnace process.

  2. Review of New Technology for Preparing Crystalline Silicon Solar Cell Materials by Metallurgical Method

    Science.gov (United States)

    Li, Man; Dai, Yongnian; Ma, Wenhui; Yang, Bin; Chu, Qingmei

    2017-11-01

    The goals of greatly reducing the photovoltaic power cost and making it less than that of thermal power to realize photovoltaic power grid parity without state subsidies are focused on in this paper. The research status, key technologies and development of the new technology for preparing crystalline silicon solar cell materials by metallurgical method at home and abroad are reviewed. The important effects of impurities and defects in crystalline silicon on its properties are analysed. The importance of new technology on reducing production costs and improving its quality to increase the cell conversion efficiency are emphasized. The previous research results show that the raw materials of crystalline silicon are extremely abundant. The product of crystalline silicon can meet the quality requirements of solar cell materials: Si ≥ 6 N, P 1 Ω cm, minority carrier life > 25 μs cell conversion efficiency of about 19.3%, the product costs dollars / kg, the product energy consumption < 30 kwh / kg. The existing problems are pointed out. The prospect of the new metallurgical process with low cost, low energy consumption, low carbon and sustainable development are prospected.

  3. Anaerobic microbiological method of cleaning water contaminated by metallurgical slags

    Directory of Open Access Journals (Sweden)

    Олена Леонідівна Дан

    2015-11-01

    Full Text Available The problem of environmental protection and rational use of water resources is one of the most important problems of environmental policy in Ukraine. This problem in Mariupol is particularly acute as metallurgical and coke industries cause significant damage to adjacent water bodies (the Kalchyk, the Kalmius and coastal zone of the Sea of Azov. One of the most harmful components of wastewater of these enterprises are sulfide-containing compounds. These compounds in water can cause great harm to both human health and the environment. For example, in 1999 the main city enterprises (AZOVSTAL IRON & STEEL WORKS and ILYICH IRON AND STEEL WORKS discharged 885,0 million m³ of wastewater (including 403,9 million m³ of polluted waste water into water bodies. The slag dumps and landfills in close proximity to the sea form a source of dangerous pollution, because contaminated water infiltration washed out here in the groundwater and surface water, get into the Sea of Azov later on. There are 97 mg/l of sulfides in the protective dam of AZOVSTAL IRON & STEEL WORKS, what exceeds the standards (MPC = 10 mg/l. It makes it possible for us to put forward biochemical purification processes. Anaerobic microbiological method proposed in the article has several advantages (compact hardware design, a minimum amount of activated sludge and lack of energy consumption for aeration over the existing wastewater treatment (chemical, mechanical, biological. The experimental procedure consisted in introducing the medium to be purified purified into microbial communities of high concentration (Thiobacillus «X», Thiobacillus concretivorus, which assimilated organic substances of the medium as a primary energy source. The kinetics of sulfide compounds removal by means of anaerobic microbiological method was considered. The effectiveness of wastewater treatment with changing purification process conditions has been also assessed (concentration of sulfides, reactor type, p

  4. Biaxial fatigue behavior of a powder metallurgical TRIP steel

    Directory of Open Access Journals (Sweden)

    S. Ackermann

    2015-10-01

    Full Text Available Multiaxial fatigue behavior is an important topic in critical structural components. In the present study the biaxial-planar fatigue behavior of a powder metallurgical TRIP steel (Transformation Induced Plasticity was studied by taking into account martensitic phase transformation and crack growth behavior. Biaxial cyclic deformation tests were carried out on a servo hydraulic biaxial tension-compression test rig using cruciform specimens. Different states of strain were studied by varying the strain ratio between the axial strain amplitudes in the range of -1 (shear loading to 1 (equibiaxial loading. The investigated loading conditions were proportional due to fixed directions of principal strains. The studied TRIP steel exhibits martensitic phase transformation from -austenite via ε-martensite into α‘- martensite which causes pronounced cyclic hardening. The α‘-martensite formation increased with increasing plastic strain amplitude. Shear loading promoted martensite formation and caused the highest α‘-martensite volume fractions at fatigue failure in comparison to uniaxial and other biaxial states of strain. Moreover, the fatigue lives of shear tests were higher than those of uniaxial and other biaxial tests. The von Mises equivalent strain hypothesis was found to be appropriate for uniaxial and biaxial fatigue, but too conservative for shear fatigue, according to literature for torsional fatigue. The COD strain amplitude which is based on crack opening displacement gave a better correlation of the investigated fatigue lives, especially those for shear loading. Different types of major cracks were observed on the sample surfaces after biaxial cyclic deformation by using electron monitoring in an electron beam universal system and scanning electron microscopy (SEM. Specimens with strain ratios of 1, 0.5, -0.1 and -0.5 showed mode I major cracks (perpendicular to the axis of maximum principal strain. Major cracks after shear fatigue

  5. THE PROFITABILITY AND LIQUIDITY UNDER THE INFLUENCE OF THE FINANCING POLICY IN THE METALLURGICAL INDUSTRY OF EU 28

    Directory of Open Access Journals (Sweden)

    DOBROTĂ GABRIELA

    2014-12-01

    Full Text Available In the context of the problems of the economic system, the use of the capital and his structure represent important elements in the process of the financial decisions. The aim of this paper is to identify the influence of funding policy on rentability in metallurgical industry, dimensioned with the help of a set of relevant indicators, determined on the base of some aggregated data for a significant sample of very large firms from EU 28. Also, the paper present the situation of liquidity, reflected through the cash- flow and liquidity ratio, in the metallurgical industry of EU 28, being used dates for the period 2004 – 2013, for the mentioned sample. The conclusion of the realised study is that a funding policy well-founded, correlated with the efficient management of expenses and proactive risk management can positively influence the profitability and liquidity.

  6. The importance of the Maillard-metal complexes and their silicates in astrobiology

    Science.gov (United States)

    Liesch, Patrick J.; Kolb, Vera M.

    2007-09-01

    The Maillard reaction occurs when sugars and amino acids are mixed together in the solid state or in the aqueous solution. Since both amino acids and sugar-like compounds are found on meteorites, we hypothesized that they would also undergo the Maillard reaction. Our recent work supports this idea. We have shown previously that the water-insoluble Maillard products have substantial similarities with the insoluble organic materials from the meteorites. The Maillard organic materials are also part of the desert varnish on Earth, which is a dark, shiny, hard rock coating that contains iron and manganese and is glazed in silicate. Rocks that are similar in appearance to the desert varnish have been observed on the Martian surface. They may also contain the organic materials. We have undertaken study of the interactions between the Maillard products, iron and other metals, and silicates, to elucidate the role of the Maillard products in the chemistry of desert varnish and meteorites. Specifically, we have synthesized a series of the Maillard-metal complexes, and have tested their reactivity towards silicates. We have studied the properties of these Maillard-metal-silicate products by the IR spectroscopy. The astrobiological potential of the Maillard-metal complexes is assessed.

  7. Low carbon steel: Metallurgical structure vs. mechanical properties

    Science.gov (United States)

    Shull, Robert D.

    1990-01-01

    The objective is to provide a low cost, simple experiment for either demonstration purposes or as a laboratory experiment that will teach the student the importance of the thermal-mechanical history of a metallic alloy in determining that material's mechanical behavior. Hairpins are subjected to various treatments. The experimental equipment and procedures are discussed.

  8. The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France

    International Nuclear Information System (INIS)

    Gandois, L.; Nicolas, M.; VanderHeijden, G.; Probst, A.

    2010-01-01

    The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (> 95% of the total output) and the plot budget (input-output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands.

  9. The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France

    Energy Technology Data Exchange (ETDEWEB)

    Gandois, L. [Universite de Toulouse, UPS, INP, EcoLab - Laboratoire d' ecologie fonctionnelle, ENSAT, Avenue de l' Agrobiopole, F-31326 Castanet-Tolosan (France); CNRS, EcoLab, F-31326 Castanet-Tolosan (France); Nicolas, M. [ONF, Direction technique RENECOFOR, Bd de Constance 77300 Fontainebleau (France); VanderHeijden, G. [INRA, centre de Nancy, Equipe BEF, 54280 Champenoux (France); Probst, A., E-mail: anne.probst@ensat.fr [Universite de Toulouse, UPS, INP, EcoLab -Laboratoire d' ecologie fonctionnelle, ENSAT, Avenue de l' Agrobiopole, F-31326 Castanet-Tolosan (France); CNRS, EcoLab, F-31326 Castanet-Tolosan (France)

    2010-11-01

    The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (> 95% of the total output) and the plot budget (input-output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands.

  10. Studies on selected organic-metal interactions of importance in the environment

    International Nuclear Information System (INIS)

    Mason, Ian.

    1995-10-01

    This research project investigated the interaction between natural organics acids and selected metal ions. The aims of the project was to provide quantitative data on the speciation of metal ions when placed in systems containing natural organic acids. It was envisaged that such data will assist in the risk assessment of the Drigg low level waste site in Cumbria. The formation and complexing ability of these natural organic acids is discussed and the classing of these acids into high molecular weight organic acids and low molecular weight organic acids. Initial investigations used a potentiometric technique to study the interaction between nickel and europium and selected low molecular weight organic acids which were thought to occur in significant concentrations in soils and groundwaters. These experiments confirmed existing critically assessed literature values, and provided an experimental methodology for further 'in-house' measurement of such values. In addition, studies were also performed on systems containing two competing organic acids. (author)

  11. Influence of metallurgical and electrochemical factors on cracking of steels at nuclear power plants under high temperature

    International Nuclear Information System (INIS)

    Pokhmurskii, V.I.; Gnyp, I.P.

    1994-01-01

    The influence of metallurgical heterogeneities in steels and electrochemical factors on corrosion cracking under high temperature water environment is studied, with special emphasis on the influence of manganese sulfide inclusions and other non-metallic ones on the crack growth rate. Results show that the electro-chemical conditions for an hydrogen concentration increase in a pre-failure zone exist at a crack tip under cyclic loading; hydrogen penetrating into metals at high temperature reduces manganese sulfides, ferric carbides, and cause high pressure of gases in micro-discontinuities, thus leading to cyclic corrosion cracking; anodic (relatively to a metal matrix) inclusions are rather the cause of steel cracking resistance decrease than cathodic ones. 16 refs., 4 figs

  12. HIT Solar Cells with N-Type Low-Cost Metallurgical Si

    Directory of Open Access Journals (Sweden)

    Xing Yang

    2018-01-01

    Full Text Available A conversion efficiency of 20.23% of heterojunction with intrinsic thin layer (HIT solar cell on 156 mm × 156 mm metallurgical Si wafer has been obtained. Applying AFORS-HET software simulation, HIT solar cell with metallurgical Si was investigated with regard to impurity concentration, compensation level, and their impacts on cell performance. It is known that a small amount of impurity in metallurgical Si materials is not harmful to solar cell properties.

  13. Soil pollution indices conditioned by medieval metallurgical activity - A case study from Krakow (Poland).

    Science.gov (United States)

    Kowalska, Joanna; Mazurek, Ryszard; Gąsiorek, Michał; Setlak, Marcin; Zaleski, Tomasz; Waroszewski, Jaroslaw

    2016-11-01

    The studied soil profile under the Main Market Square (MMS) in Krakow was characterised by the influence of medieval metallurgical activity. In the presented soil section lithological discontinuity (LD) was found, which manifests itself in the form of cultural layers (CLs). Moreover, in this paper LD detection methods based on soil texture are presented. For the first time, three different ways to identify the presence of LD in the urban soils are suggested. The presence of LD had an influence on the content and distribution of heavy metals within the soil profile. The content of heavy metals in the CLs under the MMS in Krakow was significantly higher than the content in natural horizons. In addition, there were distinct differences in the content of heavy metals within CLs. Profile variability and differences in the content of heavy metals and phosphorus within the CLs under the MMS were activity indicators of Krakow inhabitants in the past. This paper presents alternative methods for the assessment of the degree of heavy metal contamination in urban soils using selected pollution indices. On the basis of the studied total concentration of heavy metals (Zn, Pb, Cu, Mn, Cr, Cd, Ni, Sn, Ag) and total phosphorus content, the Geoaccumulation Index (I geo ), Enrichment Factor (EF), Sum of Pollution Index (PI sum ), Single Pollution Index (PI), Nemerow Pollution Index (PI Nemerow ) and Potential Ecological Risk (RI) were calculated using different local and reference geochemical backgrounds. The use of various geochemical backgrounds is helpful to evaluate the assessment of soil pollution. The individual CLs differed from each other according to the degree of pollution. The different values of pollution indices within the studied soil profile showed that LDS should not be evaluated in terms of contamination as one, homogeneous soil profile but each separate CL should be treated individually. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Solvent extraction, membranes, and ion exchange in hydrometallurgical dilute metals separation

    International Nuclear Information System (INIS)

    Tavlarides, L.L.; Bae, J.H.; Lee, C.K.

    1987-01-01

    The separation methods which are used in the hydro-metallurgical field are reviewed and compared. Some processes in solvent extraction in use for recovery of crucial metals which are important to the US defense and economy are presented. Various commercial extractants are reviewed and categorized. Other methods such as liquid membranes and ions exchange resins used for dilute metal ions separation are summarized. These methods are compared with solvent extraction. Problems to overcome in the future development of these separation methods are also identified and discussed in this paper

  15. Integration of soil magnetometry and geochemistry for assessment of human health risk from metallurgical slag dumps.

    Science.gov (United States)

    Rachwał, Marzena; Wawer, Małgorzata; Magiera, Tadeusz; Steinnes, Eiliv

    2017-12-01

    The main objective of the study was an assessment of the pollution level of agricultural land located close to dumps of industrial waste remaining after former Zn and Pb ore processing in Poland. The integrated geophysical-geochemical methods were applied for assessment of soil quality with respect to trace element pollution. Additionally, human health risk induced by the contaminated arable soil and dusting slag heap was estimated. The investigations pointed out that soils in the vicinity of the metallurgical slag dump in Piekary were heavily polluted. Spatial distribution of magnetic susceptibility corresponding well with distribution of the content of potentially toxic elements indicated the local "pollution hotspots." Proper geophysical and geochemical data interpretation supported by statistical factor analysis enabled identification of three different sources of pollution including metallurgical slug dump as a main source, but also traffic pollution influencing the area located along the busy road and relatively strong influence of the geochemical background. Computed health hazard index revealed no adverse health effect to the farmers cultivating arable soil, but in the direct vicinity of dusting, slag dump health risk occurred, caused mostly by very toxic elements as As and Tl. In the future, investigation should be focused on contribution of different sources to the heavy metal pollution in soil-crop system in this area. It should be highlighted that a site-specific approach should be taken in order to redevelop this kind of area in order to reduce ecological and human health threat. The study proved the integrated two-stage geophysical-geochemical method to be a feasible, reliable, and cost-effective tool for identification of the extent of soil pollution and areas at risk.

  16. An environmentally-friendly vacuum reduction metallurgical process to recover germanium from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lingen; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

    2016-07-15

    Highlights: • An environmental friendly vacuum reduction metallurgical process is proposed. • Rare and valuable metal germanium from coal fly ash is recycled. • Residues are not a hazardous material and can be further recycled. • A germanium recovery ratio of 94.64% is obtained in pilot scale experiments. - Abstract: The demand for germanium in the field of semiconductor, electronics, and optical devices is growing rapidly; however, the resources of germanium are scarce worldwide. As a secondary material, coal fly ash could be further recycled to retrieve germanium. Up to now, the conventional processes to recover germanium have two problems as follows: on the one hand, it is difficult to be satisfactory for its economic and environmental effect; on the other hand, the recovery ratio of germanium is not all that could be desired. In this paper, an environmentally-friendly vacuum reduction metallurgical process (VRMP) was proposed to recover germanium from coal fly ash. The results of the laboratory scale experiments indicated that the appropriate parameters were 1173 K and 10 Pa with 10 wt% coke addition for 40 min, and recovery ratio germanium was 93.96%. On the basis of above condition, the pilot scale experiments were utilized to assess the actual effect of VRMP for recovery of germanium with parameter of 1473 K, 1–10 Pa and heating time 40 min, the recovery ratio of germanium reached 94.64%. This process considerably enhances germanium recovery, meanwhile, eliminates much of the water usage and residue secondary pollution compared with other conventional processes.

  17. An important rule for realizing metal → half-metal → semiconductor transition in single-molecule junctions

    International Nuclear Information System (INIS)

    Zeng, Jing; Chen, Ke-Qiu; Long, Mengqiu

    2017-01-01

    Recently, Zhong et al (2015 Nano Lett . 15 8091) found that two additional hydrogen atoms can be adsorbed to the opposite aza-bridging nitrogen atoms of the manganese phthalocyanine (MnPc) macrocycle when exposed to H 2 . Thus the symmetry of the MnPc molecule is changed from 4-fold to 2-fold. Motivated by this recent experiment, we theoretically investigate a MnPc-based single-molecule junction in this work and propose a simple and reliable way to realize the transition of its electronic properties. On the basis of spin-polarized density-functional theory calculations combined with the Keldysh nonequilibrium Green’s technique, we find that the gradual hydrogenation in MnPc molecules gives rise to the changes of the hardness of the electron density and spin-selective orbital decoupling, which eventually leads to the realization of the first ever metal  →  half-metal  →  semiconductor transition behavior in single-molecule junctions. Analysis of molecular projected self-consistent Hamiltonian, Mulliken population, and local density of states also reveals an important rule for realizing this transition behavior. Our research confirms that the hydrogenation of MnPc molecules can realize various molecular functionalities in unitary material background. (paper)

  18. An important rule for realizing metal → half-metal → semiconductor transition in single-molecule junctions

    Science.gov (United States)

    Zeng, Jing; Chen, Ke-Qiu; Long, Mengqiu

    2017-06-01

    Recently, Zhong et al (2015 Nano Lett. 15 8091) found that two additional hydrogen atoms can be adsorbed to the opposite aza-bridging nitrogen atoms of the manganese phthalocyanine (MnPc) macrocycle when exposed to H2. Thus the symmetry of the MnPc molecule is changed from 4-fold to 2-fold. Motivated by this recent experiment, we theoretically investigate a MnPc-based single-molecule junction in this work and propose a simple and reliable way to realize the transition of its electronic properties. On the basis of spin-polarized density-functional theory calculations combined with the Keldysh nonequilibrium Green’s technique, we find that the gradual hydrogenation in MnPc molecules gives rise to the changes of the hardness of the electron density and spin-selective orbital decoupling, which eventually leads to the realization of the first ever metal  →  half-metal  →  semiconductor transition behavior in single-molecule junctions. Analysis of molecular projected self-consistent Hamiltonian, Mulliken population, and local density of states also reveals an important rule for realizing this transition behavior. Our research confirms that the hydrogenation of MnPc molecules can realize various molecular functionalities in unitary material background.

  19. Determination of heavy metals in canned vegetables. The importance of sample preparation.

    OpenAIRE

    FIAMEGKOS IOANNIS; VAHCIC MITJA; EMTEBORG HAKAN; SNELL James; RABER G.; CORDEIRO RAPOSO Fernando; ROBOUCH Piotr; DE LA CALLE GUNTINAS Maria Beatriz

    2015-01-01

    This manuscript presents the outcome of a proficiency test (PT), named IMEP-118, for the determination of total As, Cd, Pb, Hg, Sn and inorganic As (iAs) mass fractions in canned food (peas in brine). The exercise was organised by the European Union Reference Laboratory for Heavy Metals in Feed and Food (EURL-HM) to support the implementation of provisions laid down in Commission Regulation (EC) No 1881/2006, which sets maximum levels for certain contaminants in foodstuffs. With this exercise...

  20. Mechanical and metallurgical properties of carotid artery clamps.

    Science.gov (United States)

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  1. Radiation protection aspects in importing metallic scraps; Problemi di radioprotezione connessi con l`importazione di rottami metallici

    Energy Technology Data Exchange (ETDEWEB)

    Risica, S.; Di Ciacco, P. [Istituto Superiore di Sanita`, Rome (Italy). Laboratorio di Fisica

    1996-09-01

    The meeting deals with radiation protection problems caused by the possibility that radioactive metal scraps or radioactive sources hidden in the scraps, may arrive in a foundry. The importance of this issue and of rational and systematic solutions is showed by several accidents, happened in the past in numerous countries, by many signals in Italy and by some papers published in international scientific journals or reports issued by authorities and institutions in different countries.

  2. Characterization of Toxic Metals in Tobacco, Tobacco Smoke, and Cigarette Ash from Selected Imported and Local Brands in Pakistan

    OpenAIRE

    Ajab, Huma; Yaqub, Asim; Malik, Salman Akbar; Junaid, Muhammad; Yasmeen, Sadia; Abdullah, Mohd Azmuddin

    2014-01-01

    In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local ...

  3. Some results of medical researches at Ulba Metallurgical Plant

    Energy Technology Data Exchange (ETDEWEB)

    Artemieva, G.I.; Novikov, V.G.; Savchuk, V.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The results of 45-years medical researches at beryllium production of Ulba Metallurgical Plant are summarized in this report. Statistic data on different kinds of occupational diseases, related to beryllium production and the dynamics of changing occupational diseases with the development of beryllium production, are given there. Data on average duration of life of occupational disease patients are presented in the report. It includes the description of problems, related to berylliosis diagnosis. Issues, connected to beryllium production effect on health of man, located nearby beryllium production are also discussed there as well. (author)

  4. The Importance of Rare-Earth Additions in Zr-Based AB2 Metal Hydride Alloys

    Directory of Open Access Journals (Sweden)

    Kwo-Hsiung Young

    2016-07-01

    Full Text Available Effects of substitutions of rare earth (RE elements (Y, La, Ce, and Nd to the Zr-based AB2 multi-phase metal hydride (MH alloys on the structure, gaseous phase hydrogen storage (H-storage, and electrochemical properties were studied and compared. Solubilities of the RE atoms in the main Laves phases (C14 and C15 are very low, and therefore the main contributions of the RE additives are through the formation of the RENi phase and change in TiNi phase abundance. Both the RENi and TiNi phases are found to facilitate the bulk diffusion of hydrogen but impede the surface reaction. The former is very effective in improving the activation behaviors. −40 °C performances of the Ce-doped alloys are slightly better than the Nd-doped alloys but not as good as those of the La-doped alloys, which gained the improvement through a different mechanism. While the improvement in ultra-low-temperature performance of the Ce-containing alloys can be associated with a larger amount of metallic Ni-clusters embedded in the surface oxide, the improvement in the La-containing alloys originates from the clean alloy/oxide interface as shown in an earlier transmission electron microscopy study. Overall, the substitution of 1 at% Ce to partially replace Zr gives the best electrochemical performances (capacity, rate, and activation and is recommended for all the AB2 MH alloys for electrochemical applications.

  5. Termination of the Special Metallurgical (SM) Building at Mound Laboratory: a final report

    International Nuclear Information System (INIS)

    Harris, W.R.; Kokenge, B.R.; Marsh, G.C.

    1976-01-01

    The report describes and highlights the more important factors associated with the termination of the Special Metallurgical (SM) Building at Mound Laboratory. As a result, a written record of the more important techniques and procedures is now available for reference by others involved in similar termination efforts. Included in this report is a description of the organizational units that were used in this effort along with a description of their responsibilities. A general description of the SM Building and a discussion of the more relevant procedures and equipment that were used are also presented. In addition, pertinent Health Physics information, such as personnel exposure, final wipe levels in the terminated facility, and assays of the structure, are provided. Based on the experience gained from this project, recommendations were made regarding the design of future radioactive material handling facilities so that when they are ultimately terminated the effort can be accomplished more efficiently

  6. Characterization of toxic metals in tobacco, tobacco smoke, and cigarette ash from selected imported and local brands in Pakistan.

    Science.gov (United States)

    Ajab, Huma; Yaqub, Asim; Malik, Salman Akbar; Junaid, Muhammad; Yasmeen, Sadia; Abdullah, Mohd Azmuddin

    2014-01-01

    In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.

  7. Characterization of Toxic Metals in Tobacco, Tobacco Smoke, and Cigarette Ash from Selected Imported and Local Brands in Pakistan

    Directory of Open Access Journals (Sweden)

    Huma Ajab

    2014-01-01

    Full Text Available In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS. Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.

  8. The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Alexandre Luiz de Souza; Silva, Cristiano Nunes da; Afonso, Julio Carlos, E-mail: julio@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica; Mantovano, Jose Luiz [Instituto de Engenharia Nuclear (CNEN/IEN-RJ), Rio de Janeiro, RJ (Brazil). Dept. de Quimica e Materiais Nucleares

    2011-07-01

    This work describes a three-step pre-treatment route for processing spent commercial Ni Mo/Al{sub 2}O{sub 3} catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L{sup -1} sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo) during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate. (author)

  9. The importance of pre-treatment of spent hydrotreating catalysts on metals recovery

    Directory of Open Access Journals (Sweden)

    Alexandre Luiz de Souza Pereira

    2011-01-01

    Full Text Available This work describes a three-step pre-treatment route for processing spent commercial NiMo/Al2O3 catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L-1 sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate.

  10. The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France.

    Science.gov (United States)

    Gandois, L; Nicolas, M; VanderHeijden, G; Probst, A

    2010-11-01

    The trace metal (TM: Cd, Cu, Ni, Pb and Zn) budget (stocks and annual fluxes) was evaluated in a forest stand (silver fir, Abies alba Miller) in north-eastern France. Trace metal concentrations were measured in different tree compartments in order to assess TM partitioning and dynamics in the trees. Inputs included bulk deposition, estimated dry deposition and weathering. Outputs were leaching and biomass exportation. Atmospheric deposition was the main input flux. The estimated dry deposition accounted for about 40% of the total trace metal deposition. The relative importance of leaching (estimated by a lumped parameter water balance model, BILJOU) and net biomass uptake (harvesting) for ecosystem exportation depended on the element. Trace metal distribution between tree compartments (stem wood and bark, branches and needles) indicated that Pb was mainly stored in the stem, whereas Zn and Ni, and to a lesser extent Cd and Cu, were translocated to aerial parts of the trees and cycled in the ecosystem. For Zn and Ni, leaching was the main output flux (>95% of the total output) and the plot budget (input-output) was negative, whereas for Pb the biomass net exportation represented 60% of the outputs and the budget was balanced. Cadmium and Cu had intermediate behaviours, with 18% and 30% of the total output relative to biomass exportation, respectively, and the budgets were negative. The net uptake by biomass was particularly important for Pb budgets, less so for Cd and Cu and not very important for Zn and Ni in such forest stands. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Market Structure Differences Impacting Australian Iron Ore and Metallurgical Coal Industries

    Directory of Open Access Journals (Sweden)

    Kurt Lawrence

    2015-07-01

    Full Text Available Steelmaking relies on iron ore and metallurgical coal as main ingredients, the trade of which is hypothesized to theoretically change in tandem. However, strong correlation is not evident in historical trade prices of steelmaking inputs. To determine causes to this occurrence, the market factors that influence the Australian iron ore and metallurgical coal industries were studied. Data was collected over the past decade for worldwide resource production and trade quantities of crude steel, iron ore, and metallurgical coal. The data was analysed to reveal trends, allowing examination of the macroeconomic trade of metallurgical coal and iron ore with relation to worldwide and country specific steel production. It was determined that the influential growth of China’s steel production has spurred the growth of worldwide iron ore demand, which was met with increased production and supply, from Australia. The increased metallurgical coal demand has been met with increased production within China locally. Measures of supply elasticity were created for worldwide iron ore and metallurgical coal trade, where comparisons between Australia’s industries to the relevant greatest competitor were examined. The results, along with respective resource production data, highlighted the elevated competitive position that Australian iron ore producers enjoy compared to metallurgical coal producers. Trade characteristics revealed the different market structures that iron ore and metallurgical coal industries operate in, prompting a discussion of the effects these markets have on the two Australian industries.

  12. Transportation of volatile elements in thermally evolving planetesimals: An important role of metallic iron

    Science.gov (United States)

    Hashizume, K.; Sugiura, N.

    1994-01-01

    Ordinary chondrites are considered to have experienced thermal metamorphism in small bodies. We are interested in behaviors of volatile elements in such a kind of thermally evolving planetesimals. Volatile elements generally have high vapor pressures at high temperature. In porous bodies, with a high gas permeability, volatile elements are transported efficiently over a long range. Behavior of volatile elements transported by permeable gas flow can be handled by an equation whose form is similar to that of the equation of thermal diffusion. We can follow transportation of heats and volatile elements in planetesimals, when parameters in these equations, initial conditions and chemical behavior of volatile elements are given. Recently, we discovered that nitrogen in equilibrated H-chondrites is mainly trapped in taenite (f.c.c. Fe-Ni), probably dissolved in interstitial sites. Fegley suggests that metallic iron cannot trap nitrogen in the solar nebula gas due to its very low nitrogen partial pressure. Approximately 1 bar of nitrogen pressure is required to explain the nitrogen content in taenite. We may expect high nitrogen gas partial pressure (possibly produced by vaporization of nitrogen-bearing solids such as organic materials) at the interior of thermally evolving planetesimals. Kinetic behavior of nitrogen in taenite suggests that it can easily be equilibrated with the ambient nitrogen gas at temperatures of approximately 500 C or higher. We consider that nitrogen is trapped in taenite through a nitrogen redistribution process occurred during the thermal metamorphic event.

  13. High power density systems used in advanced metallurgical applications and safety aspects

    International Nuclear Information System (INIS)

    Mirji, K.V.; Ramesh, N.

    2016-01-01

    This topic concerns about the operation and development of electron beam (EB) machines utilized in metallurgical applications such as EB melting and EB welding. They are popular in purification of refractory metals and welding of their alloy components. In this equipment, EB generation, acceleration, harnessing and energy dissipation need to be performed under high vacuum conditions. The high voltage required for acceleration is generated by using 3 phase 415 Volts, 50 Hz ac power supply. The transformers used have to be specially designed to withstand frequent, high short circuit currents which result from discharges during processing. The high voltage rectifiers are similarly designed to cater to such duties, apart from generating high voltage with low ripple contents. Apart from trans-rectifiers, the cables need to be designed with proper termination at the gun to ensure safety of operating personnel, while ensuring ease of connection. Practical problems of electric discharges due to sudden evolution of gaseous and metallic impurities, proper dissipation of residual charge on cathode assembly and the EB gun need to be handled carefully. (author)

  14. EDXRF and micro-EDXRF studies of Late Bronze Age metallurgical productions from Canedotes (Portugal)

    Science.gov (United States)

    Valerio, Pedro; Araújo, M. de Fátima; Canha, Alexandre

    2007-10-01

    Metallurgical production in Central Portugal during the Late Bronze Age was primarily based on copper-tin alloys, despite influences from the Atlantic area where copper-tin-lead alloys are common. Metallic artefacts from archaeological site of Canedotes (Central Portugal) were analysed by EDXRF to establish the type of alloys present. Polished spots in selected artefacts were also analysed by micro-EDXRF to determine the major and minor elemental composition of the original alloys. The collection constitutes 18 copper-tin artefacts and one unalloyed copper artefact with tin and arsenic as minor constituents. Artefacts that require a thermomechanical finishing process, such as tools and weapons, seem to have improved control over the tin content. The composition of two buttons, one cramp and one metallic droplet suggest that some of the copper sources were rich in arsenic. Finally, the low iron content of the artefacts seems to agree well with the smelting of copper ores in crucible furnaces, a smelting process used in certain areas of the Iberian Peninsula until pre-Roman times.

  15. Relative importance of different exposure routes of heavy metals for humans living near a municipal solid waste incinerator.

    Science.gov (United States)

    Li, Tong; Wan, Yi; Ben, Yujie; Fan, Senrong; Hu, Jianying

    2017-07-01

    The potential health effects of toxic chemicals (e.g. heavy metals) emitted by municipal solid waste incinerators (MSWIs) are of great concern to local residents, however there have been few studies on the contributions of different exposure pathways and their subsequent effects on the body burden of residents living near MSWIs. In this study, multiple exposure routes of heavy metals including Pb, Cr, Cd and Mn were assessed by investigating the metals in foods (such as vegetables, crops, meats and fruits etc.), drinking water, ambient air and soil collected surrounding an MSWI in Shenzhen, south China. Vegetable ingestion played the most important role in the total average daily dose of Pb and Cr, and cereals were the key exposure routes for Mn and Cd. Compound-specific contaminations were observed in the investigated areas, with Pb and Cr present in the surrounding environment, having accumulated to relatively high levels in the local vegetables, and the intake of contaminated vegetable foods greatly influencing the body burden of Pb and Cr. Consistently, significantly high blood concentrations of Pb and Cr were detected in the local residents compared to a referenced population, and a lack of significant differences was found for Cd and Mn. The results possibly suggested that emission of MSWI influenced the external exposure doses of the major pathways of Pb and Cr in this study, and resulted in the different body burden of metals in humans living near a MSWI. MSWI-local food-humans is an important exposure pathway for residents living near MSWI, and thus should not be neglected in developing future strategies and policies to prevent the high risks suffered by residents living near MSWIs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Employment and other selected personnel attributes in metallurgical and industrial enterprises of different size - research results

    Directory of Open Access Journals (Sweden)

    A. Pawliczek

    2015-10-01

    Full Text Available The presented paper deals with the issue of employment and other selected personnel attributes as employees’ affiliations, employees’ benefits, monitoring of employees’ satisfaction, monitoring of work productivity, investments into employees education and obstacles in hiring qualified human resources. The characteristics are benchmarked on the background of enterprise size based on the employees count in the year 2013. The relevant data were collected in Czech industrial enterprises, including metallurgical companies, with the help of university questionnaire research in order to induce synergy effect arising from mutual communication of academy-students-industry. The most important results are presented later in the paper, complemented with discussion based on relevant professional literature sources. The findings suggest that bigger companies check productivity and satisfaction and dismiss employees more frequently, unlike medium companies which do not reduce their workforce and solve the impact of crisis by decreased affiliations, reduced benefits and similar savings.

  17. Roadmap report of the Metallurgical Industry and Foundries [in the Netherlands]; Rapportage Routekaart Metallurgische Industrie en Gieterijen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-08-15

    The roadmap describes the direction VNMI and AVNeG consider as feasible to realize substantial improvements with regard to energy efficiency in metallurgical production processes and in the usage of metal products. The aim of the report is to guide development efforts and describe technical and organizational options for businesses and industries in the metal sector [Dutch] De Routekaart beschrijft de richting die VNMI en AVNeG als haalbaar zien om naar 2030 toe substantiele energie-efficientieverbeteringen te realiseren in metallurgische productieprocessen en in de gebruiksfase van metaal producten. Het rapport is richtinggevend voor ontwikkelingsinspanningen en beschrijft technische en organisatorische mogelijkheden waar bedrijven individueel en in sectorverband zich voor zullen inzetten.

  18. The Metal Neurotoxins: An Important Role in Current Human Neural Epidemics?

    Directory of Open Access Journals (Sweden)

    Keith Schofield

    2017-12-01

    Full Text Available Many published studies have illustrated that several of the present day neurological epidemics (autism, attention deficit disorder, Alzheimer’s cannot be correlated to any single neurotoxicant. However, the present scientific examination of the numerous global blood monitoring databases for adults that include the concentrations of the neurotoxic elements, aluminum (Al, arsenic (As, lead (Pb, manganese (Mn, mercury (Hg, and selenium (Se clearly indicate that, when considered in combination, for some, the human body may become easily over-burdened. This can be explained by changes in modern lifestyles. Similar data, solely for pregnant women, have been examined confirming this. All these elements are seen to be present in the human body and at not insignificant magnitudes. Currently suggested minimum risk levels (MRL for humans are discussed and listed together with averages of the reported distributions, together with their spread and maximum values. One observation is that many distributions for pregnant women are not too dissimilar from those of general populations. Women obviously have their individual baseline of neurotoxin values before pregnancy and any efforts to modify this to any significant degree is not yet clearly apparent. For any element, distribution shapes are reasonably similar showing broad distributions with extended tails with numerous outlier values. There are a certain fraction of people that lie well above the MRL values and may be at risk, especially if genetically susceptible. Additionally, synergistic effects between neurotoxins and with other trace metals are now also being reported. It appears prudent for women of child-bearing age to establish their baseline values well before pregnancy. Those at risk then can be better identified. Adequate instrumental testing now is commercially available for this. In addition, directives are necessary for vaccination programs to use only non-neurotoxic adjuvants, especially for

  19. Metallurgical Effects of Shunting Current on Resistance Spot-Welded Joints of AA2219 Sheets

    Science.gov (United States)

    Jafari Vardanjani, M.; Araee, A.; Senkara, J.; Jakubowski, J.; Godek, J.

    2016-08-01

    Shunting effect is the loss of electrical current via the secondary circuit provided due to the existence of previous nugget in a series of welding spots. This phenomenon influences on metallurgical aspects of resistance spot-welded (RSW) joints in terms of quality and performance. In this paper RSW joints of AA2219 sheets with 1 mm thickness are investigated metallurgically for shunted and single spots. An electro-thermal finite element analysis is performed on the RSW process of shunted spot and temperature distribution and variation are obtained. These predictions are then compared with experimental micrographs. Three values of 5 mm, 20 mm, and infinite (i.e., single spot) are assumed for welding distance. Numerical and experimental results are matching each other in terms of nugget and HAZ geometry as increasing distance raised nugget size and symmetry of HAZ. In addition, important effect of shunting current on nugget thickness, microstructure, and Copper segregation on HAZ grain boundaries were discovered. A quantitative analysis is also performed about the influence of welding distance on important properties including ratio of nugget thickness and diameter ( r t), ratio of HAZ area on shunted and free side of nugget ( r HA), and ratio of equivalent segregated and total amount of Copper, measured in sample ( r Cu) on HAZ. Increasing distance from 5 mm to infinite, indicated a gain of 111.04, -45.55, and -75.15% in r t, r HA, and r Cu, respectively, while obtained ratios for 20 mm welding distance was suitable compared to single spot.

  20. Performance analysis of locomotive park of the transport service of rolling mills metallurgical enterprises

    Directory of Open Access Journals (Sweden)

    Ганна Вікторовна Маслак

    2017-07-01

    Full Text Available In terms of market economy it is highly important to implement new transport and energy-saving technologies into industrial enterprises and industrial objects’ workflow. And the main point here is employment of traction means which secure considerable economy in transport costs and, first and foremost, energy consumption. The issue of transport service of the rolling shop at a metallurgical enterprise is of high importance from the point of view of railway traction means utilization effectiveness, i.e. locomotives utilization within the process of shunting (which is carried out at railway tracks serving loading and unloading sites of the rolling shop. The article assesses operational indicators of locomotives’ performance by the time, power and adhesion weight within serving transport-and-handling complex of rolling shop at metallurgical enterprise. With this purpose transport technology of transport-and-handling complex of rolling shop is taken into consideration. In order to make the performance assessment of the locomotive fleet operation, algorithm of research has been developed. In accordance with this algorithm, operational parameters for TGM-4 locomotives exploitation have been defined (the data is provided for locomotive operation during a shift.Adhesion weight and locomotive power calculations have been made for work and after-hours runs. The analysis shows the level of inefficiency of locomotives use. One of the main ways of saving these costs is substitution of high-powered locomotives with energy-saving traction means. This issue can be solved at the expense of traction means based on wheeled tractors or self-propelled chassis which can be used either on a road or on a railway track. In accordance with operational conditions, qualification of tractive effort and other parameters, the effectiveness of traction means utilization at railway- and auto-transportations significantly increases

  1. Metal recovery from high-grade WEEE

    DEFF Research Database (Denmark)

    Bigum, Marianne; Brogaard, Line Kai-Sørensen; Christensen, Thomas Højlund

    2012-01-01

    Based on available data in the literature the recovery of aluminium, copper, gold, iron, nickel, palladium and silver from high-grade WEEE was modeled by LCA. The pre-treatment of WEEE included manual sorting, shredding, magnetic sorting, Eddy-current sorting, air classification and optical sorting...... and refining of ore. The resource recovery per tonne of high-grade WEEE ranged from 2 g of palladium to 386 kg of iron. Quantified in terms of person-equivalents the recovery of palladium, gold, silver, nickel and copper constituted the major environmental benefit of the recovery of metals from WEEE...... effect compared to the metallurgical treatment. However only 12-26% of silver, gold and palladium are recovered during pre-treatment, which suggest that the reduction of the apparent losses of precious metals as palladium, gold and silver during pre-treatment of WEEE is of environmental importance. Our...

  2. Odonata larvae as a bioindicator of metal contamination in aquatic environments: application to ecologically important wetlands in Iran.

    Science.gov (United States)

    Nasirian, Hassan; Irvine, K N

    2017-09-01

    The objectives of this study were twofold: (i) assess the bioaccumulation characteristics of a suite of metals associated with several different species of Odonata and (ii) examine Odonata species richness as a reflection of ecosystem health in two ecologically important wetlands of southwestern Iran, the Shadegan and Hawr Al Azim wetlands. Levels of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), lead (Pb), and zinc (Zn) were determined using inductively coupled plasma optical emission spectrometry (ICP-OES) in nine different Odonata larva species. Based on these data, biota-sediment accumulation factors (BSAFs) were calculated and generally, it was found that Cr, Cu, Mn, and Zn were being taken up by the Odonata (BSAFs >1). Because of its prevalence in the wetland and its observed ability to take up metals, it is suggested that Ischnura ramburii is an appropriate indicator of ecosystem health for these wetlands with respect to metal contamination. Odonata species richness across all sites was 49, while for the individual sites, the greatest species richness was 26 and the lowest species richness was 13. The species richness value across all sites is quite healthy, given the arid climate of the region.

  3. Extreme conditions synthesis, processing and characterization of metal-nitrides and alloys of mechanical and optoelectronic importance

    International Nuclear Information System (INIS)

    Serghiou, G; McGaff, A J; Russell, N; Morniroli, J P; Frost, D J; Odling, N; Boehler, R; Troadec, D; Lathe, C

    2010-01-01

    High density nitrides and group IV alloys are of growing importance for both ceramic and optoelectronic applications. We present here new data and processes in our ongoing preparation of alkaline earth and transition metal nitrides as well as group IV alloys, here, up to 25 GPa and 2300 K. We employ large volume and laser-heated diamond anvil cell techniques for synthesis, processing tools including focused ion beam, and synchrotron X-ray diffraction, transmission electron microscopy and scanning electron microscopy for characterization.

  4. Metallurgical and mechanical behaviours of PWR fuel cladding tube oxidised at high temperature

    International Nuclear Information System (INIS)

    Stern, A.

    2007-12-01

    Zirconium alloys are used as cladding materials in Pressurized Water Reactors (PWR). As they are submitted to very extreme conditions, it is necessary to check their behaviour and especially to make sure they meet the safety criteria. They are therefore studied under typical in service-loadings but also under accidental loadings. In one of these accidental scenarios, called Loss of Coolant Accident (LOCA) the cladding temperature may increase above 800 C, in a steam environment, and decrease before a final quench of the cladding. During this temperature transient, the cladding is heavily oxidised, and the metallurgical changes lead to a decrease of the post quench mechanical properties. It is then necessary to correlate this drop in residual ductility to the metallurgical evolutions. This is the problem we want to address in this study: the oxidation of PWR cladding materials at high temperature in a steam environment and its consequences on post quench mechanical properties. As oxygen goes massively into the metallic part - a zirconia layer grows at the same time - during the high temperature oxidation, the claddings tubes microstructure shows three different phases that are the outer oxide layer (zirconia) and the inner metallic phases (α(O) and 'ex β') - with various mechanical properties. In order to reproduce the behaviour of this multilayered material, the first part of this study consisted in creating samples with different - but homogeneous in thickness - oxygen contents, similar to those observed in the different phases of the real cladding. The study was especially focused on the β-->α phase transformation upon cooling and on the resulting microstructures. A mechanism was proposed to describe this phase transformation. For instance, we conclude that for our oxygen enriched samples, the phase transformation kinetics upon cooling are ruled by the oxygen partitioning between the two allotropic phases. Then, these materials were mechanically tested at

  5. Importance of different types of marine particles for the scavenging of heavy metals in the deep-sea bottom water

    International Nuclear Information System (INIS)

    Koschinsky, A.; Winkler, A.; Fritsche, U.

    2003-01-01

    In experiments of 7 days duration using voltammetric and radiotracer measurement techniques, the role of different particle types in the sorption of dissolved metal species in a disturbed deep-sea bottom seawater system were investigated. Resuspension of oxic to suboxic surface sediment into the bottom water in the deep sea (either by natural events or industrial activities like Mn nodule mining) has been shown to be followed quickly by scavenging of dissolved heavy metals, e.g. released from interstitial water, on the resuspended particles. Compared to other deep-sea particles (like clay minerals, calcite and apatite), Mn and Fe oxides and oxyhydroxides were found to be by far the most important phases in scavenging many dissolved heavy metals. Only Pb was sorbed strongly on all particles used, with highest affinity to carbonate fluorapatite. Caesium + was significantly scavenged only by clay minerals like illite. The sorption experiments support a simple electrostatic model: Hydrated cations and labile cationic chloro-complexes in seawater like Mn 2+ , MnCl + , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Ba 2+ , and PbCl + , are preferentially adsorbed or ion-exchanged on the negatively charged surfaces of Mn oxides. In contrast, oxyanions and neutrally or negatively charged complexes like HVO 4 2- , MoO 4 2- , HAsO 4 2- , UO 2 (CO 3 ) 2 2- , and PbCO 3 0 associate with neutral to slightly positive amphoteric Fe oxyhydroxide particles. Metals forming strong chloro-complexes in seawater like Cd (CdCl 2 0 ), are less readily sorbed by oxides than others. A comparison of the results of voltammetric and radiotracer techniques revealed that after fast sorption within the first hour, isotopic exchange dominated reactions on MnO 2 -rich particles in the following days. This was especially pronounced for Mn and Co which are bound to the Mn oxide surface via a redox transformation

  6. Integrated Multimotor Electrical DC Drive for Metallurgical Rolling Table

    Directory of Open Access Journals (Sweden)

    Gała Marek

    2015-06-01

    Full Text Available A drive system of a section of a metallurgical rolling table consisting of six dc motors, 2220 amperes of total current, fed from a single ABB reversible thyristor converter has been described in this paper. Autonomous excitation circuits of the motors are fed from independent thyristor converters working in the so called MULTIFEX system linked with a supervisory high power converter. There are presented schemes of the DSL communication realized by FEX excitation cards of the motors using the SDSC card of the DCS-800-S02 converter and logic control system based on a PLC controller. The parameterization of the DCS-800 converter and the DCF 803 excitation systems was conducted using the DriveWindow software tool. Significant waveforms of voltages, currents and the estimated motor velocity are described and presented for the idle run as well as during transporting sheets discharged from a pusher furnace.

  7. First Mining workshop of Mining and metallurgical of MERCOSUR

    International Nuclear Information System (INIS)

    1994-01-01

    In the city of Montevideo, capital of the Oriental Republic of Uruguay, at 23 days of September 1994, under the First Meeting of Mercosur Mining Metallurgical, meet representatives of the mining sector in the countries signed the Treaty of Asuncion , attended as observers, authorities of the Republic of Bolivia and Ecuador and representatives of the productive labor, legislative and research. The primary objective is to integrate the mining sectors of those countries, taking into account the specificity of the mining, given by the resource it uses, the need for high-risk investment with slow recoveries of capital and infrastructure problems, taking into account leverage and its remarkable impact on the development of regional economies.

  8. Peer review of the Three Mile Island Unit 2 Vessel Investigation Project metallurgical examinations

    International Nuclear Information System (INIS)

    Bohl, R.W.; Gaydos, R.G.; Vander Voort, G.F.; Diercks, D.R.

    1994-07-01

    Fifteen samples recovered from the lower head of the Three Mile Island (TMI) Unit 2 nuclear reactor pressure vessel were subjected to detailed metallurgical examinations by the Idaho National Engineering Laboratory (INEL), with supporting work carried out by Argonne National Laboratory (ANL) and several of the European participants. These examinations determined that a portion of the lower head, a so-called elliptical ''hot spot'' measuring ∼0.8 x 1 m, reached temperatures as high as 1100 degrees C during the accident and cooled from these temperatures at ∼10--100 degrees C/min. The remainder of the lower head was found to have remained below the ferrite-toaustenite transformation temperature of 727 degrees C during the accident. Because of the significance of these results and their importance to the overall analysis of the TMI accident, a panel of three outside peer reviewers, Dr. Robert W. Bohl, Mr. Richard G. Gaydos, and Mr. George F. Vander Voort, was formed to conduct an independent review of the metallurgical analyses. After a thorough review of the previous analyses and examination of photo-micrographs and actual lower head specimens, the panel determined that the conclusions resulting from the INEL study were fundamentally correct. In particular, the panel reaffirmed that four lower head samples attained temperatures as high as 1100 degrees C, and perhaps as high as 1150--1200 degrees C in one case, during the accident. They concluded that these samples subsequently cooled at a rate of ∼50--125 degrees C/min in the temperature range of 600--400 degrees C, in good agreement with the original analysis. The reviewers also agreed that the remainder of the lower head samples had not exceeded the ferrite-to-austenite transformation temperature during the accident and suggested several refinements and alternative procedures that could have been employed in the original analysis

  9. Peer review of the Three Mile Island Unit 2 Vessel Investigation Project metallurgical examinations

    Energy Technology Data Exchange (ETDEWEB)

    Bohl, R.W.; Gaydos, R.G.; Vander Voort, G.F.; Diercks, D.R. [Argonne National Lab., IL (United States)

    1994-07-01

    Fifteen samples recovered from the lower head of the Three Mile Island (TMI) Unit 2 nuclear reactor pressure vessel were subjected to detailed metallurgical examinations by the Idaho National Engineering Laboratory (INEL), with supporting work carried out by Argonne National Laboratory (ANL) and several of the European participants. These examinations determined that a portion of the lower head, a so-called elliptical ``hot spot`` measuring {approx}0.8 {times} 1 m, reached temperatures as high as 1100{degrees}C during the accident and cooled from these temperatures at {approx}10--100{degrees}C/min. The remainder of the lower head was found to have remained below the ferrite-toaustenite transformation temperature of 727{degrees}C during the accident. Because of the significance of these results and their importance to the overall analysis of the TMI accident, a panel of three outside peer reviewers, Dr. Robert W. Bohl, Mr. Richard G. Gaydos, and Mr. George F. Vander Voort, was formed to conduct an independent review of the metallurgical analyses. After a thorough review of the previous analyses and examination of photo-micrographs and actual lower head specimens, the panel determined that the conclusions resulting from the INEL study were fundamentally correct. In particular, the panel reaffirmed that four lower head samples attained temperatures as high as 1100{degrees}C, and perhaps as high as 1150--1200{degrees}C in one case, during the accident. They concluded that these samples subsequently cooled at a rate of {approx}50--125{degrees}C/min in the temperature range of 600--400{degrees}C, in good agreement with the original analysis. The reviewers also agreed that the remainder of the lower head samples had not exceeded the ferrite-to-austenite transformation temperature during the accident and suggested several refinements and alternative procedures that could have been employed in the original analysis.

  10. The metallurgical integrity of the frit vent assembly diffusion bond

    Science.gov (United States)

    Ulrich, G. B.

    1994-06-01

    Iridium alloy clad vent sets (CVS's) are now being made by Energy Systems at the Oak Ridge Y-12 Plant. These CVS's are being made for the US Department of Energy's (NE-53) General Purpose Heat Source- Radioisotope Thermoelectric Generator (GPHS-RTG) program, which is to supply electrical power for the National Aeronautics and Space Administration's Cassini mission to Saturn. A GPHS-RTG has 72 CVS'. Each CVS encapsulates one (238)PuO2 fuel pellet. The helium gas produced from the alpha decay of the (238)Pu is vented through a nominal 0.45-mm-diam hole in the vent cup of each CVS. A frit vent assembly that is electron beam welded over the vent hole allows helium gas to escape but prevents plutonia fines from exiting. The metallurgical integrity of frit vent assemblies produced by Martin Marietta Energy Systems, Inc. (Energy Systems) were compared with those produced earlier by EG&G-Mound Applied Technology, Inc. (EG&G-MAT). Scanning electron microscope (SEM) photographs were taken (at magnifications of from 126x to 1,000x) of the starting frit vent powder and the diffusion-bonded powder in finished frit vent assemblies produced by Energy Systems and EG&G-MAT. Frit vent assemblies also were metallographically prepared and visually examined/photographed at magnifications of from 50x to 1,000x. The SEM and metallographic examinations of the particle-to-particle and particle-to-foil component diffusion bonds indicated that the Energy Systems-produced and EG&G-MAT-produced frit vent assemblies have comparable metallurgical integrity. Statistical analysis of the Energy Systems production data shows that the frit vent manufacturing yield is 91%.

  11. Process of optimization of district heat production by utilizing waste energy from metallurgical processes

    Science.gov (United States)

    Konovšek, Damjan; Fužir, Miran; Slatinek, Matic; Šepul, Tanja; Plesnik, Kristijan; Lečnik, Samo

    2017-07-01

    In a consortium with SIJ (Slovenian Steel Group), Metal Ravne, the local community of Ravne na Koro\\vskem and the public research Institut Jožef Stefan, with its registered office in Slovenia, Petrol Energetika, d.o.o. set up a technical and technological platform of an innovative energy case for a transition of steel industry into circular economy with a complete energy solution called »Utilization of Waste Heat from Metallurgical Processes for District Heating of Ravne na Koro\\vskem. This is the first such project designed for a useful utilization of waste heat in steel industry which uses modern technology and innovative system solutions for an integration of a smart, efficient and sustainable heating and cooling system and which shows a growth potential. This will allow the industry and cities to make energy savings, to improve the quality of air and to increase the benefits for the society we live in. On the basis of circular economy, we designed a target-oriented co-operation of economy, local community and public research institute to produce new business models where end consumers are put into the centre. This innovation opens the door for steel industry and local community to a joint aim that is a transition into efficient low-carbon energy systems which are based on involvement of natural local conditions, renewable energy sources, the use of waste heat and with respect for the principles of sustainable development.

  12. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Fourth quarter 1992 and 1992 summary

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C.Y.

    1993-03-01

    During fourth quarter 1992, samples from 18 groundwater monitoring wells of the AMB series at the Metallurgical Laboratory Hazardous Waste Management Facility were analyzed for certain heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Six parameters exceeded final Primary Drinking Water Standards (PDWS) and the Savannah River Site Flag 2 criteria during the quarter. The results for fourth quarter 1992 are fairly consistent with the rest of the year`s data. Tetrachloroethylene exceeded the final PDWS in well AMB 4D only two of the four quarters; in the other three wells in which it was elevated, it was present at similar levels throughout the year. Trichloroethylene consistently exceeded its PDWS in wells AMB 4A, 4B, 4D, 5, and 7A during the year. Trichloroethylene was elevated in well AMB 6 only during third and fourth quarters and in well AMB 7 only during fourth quarter. Total alpha-emitting radium was above the final PDWS for total radium in well AMB 5 at similar levels throughout the year and exceeded the PDWS during one of the three quarters it was analyzed for (third quarter 1992) in well AMB 10B.

  13. Metallurgical Laboratory Hazardous Waste Management Facility groundwater monitoring report. Third quarter, 1994

    International Nuclear Information System (INIS)

    1994-12-01

    During third quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Bis(2-ethylhexyl) phthalate exceeded final PDWS in one well. Aluminum, iron, manganese, tin, and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to previous quarters. During second quarter 1994, SRS received South Carolina Department of Health and Environmental Control approval for constructing five point-of-compliance wells and two plume definition wells near the Met Lab HWMF. This project began in July 1994 and is complete; however, analytical data from these wells is not available yet

  14. Measures to detect and control radioactive contaminated metallurgical scrap at border checkpoints in Poland

    International Nuclear Information System (INIS)

    Smagala, G.

    1999-01-01

    The issue of radioactive contaminated metallurgical scrap has never received a high priority in Poland and in the international community. Since the dissolution of the former Soviet Union a higher attention has been given to the problem. Poland which is located between the West and East Europe has the obligation to develop and implement an effective prevention and detection system. The reasons to increase national control and detection system at the border checkpoints in Poland are to avoid the following risks: post Chernobyl contamination transports of commodities; transport of contaminated metal scrap; transfer of radioactive waste for their disposal or utilization; high risk of becoming a transit country of illicit trafficking of nuclear materials and radioactive sources. In order to avoid the above-mentioned risks, Poland initiated in 1990, a deployment of the portable radiation devices at the border checkpoints and, as of 1998, the number of installed instruments exceeded a hundred. This paper presents Poland's activities to detect contaminated scrap at its border checkpoints. (author)

  15. A review of recent developments in ion implantation for metallurgical application

    International Nuclear Information System (INIS)

    Hutchings, Ron

    1994-01-01

    Ion implantation emerged during the 1970s as a possible tool for improving the wear and corrosion resistance of metals and alloys. This emergence led to a period of intense activity in the early 1980s, aimed at identifying opportunities for the industrial application of ion implantation. This paper reviews the progress which has been made towards establishing ion implantation as an effective and reliable technique for improving the wear resistance of engineering materials. Particular emphasis is placed on the implantation of nitrogen. It is shown how detailed metallurgical studies have elucidated the role played by the implanted nitrogen in enhancing the resistance to wear of a broad range of alloys. These studies have highlighted the fact that the thin nature of the implanted layer has been a prime factor in restricting the industrial usage of ion implantation to a narrow range of specialized applications. This has resulted in a shift to the development of duplex treatments involving two-stage processes or, more recently, new techniques which allow simultaneous implantation and thermochemical treatment. The capabilities of, and future prospects for, such techniques are discussed. ((orig.))

  16. Model for temperature profile estimation in the refractory of a metallurgical ladle

    Science.gov (United States)

    Fredman, T. P.; Saxén, H.

    1998-06-01

    Modeling of the transient thermal state of metallurgical ladels is motivated by the need for estimating the drop in temperature of the liquid metal in the ladle. On-line estimation of the state is required, since the same ladle is used in a number of casting cycles with rapid changes in boundary conditions for the temperature field, and the conditions in the current as well as previous cycles affect the thermal state. Although a large number of methods for the numerical solution of conduction-diffusion partial differential equations have been developed, there are still advantages to keeping thermal field computations at a relatively simple level, in contrast to the situation in the design process of ladles, where two-dimensional modeling may be required. Extensive computations under nonverifiable boundary and initial parameter values are not especially suited for real-time simulation of industrial processes. This article presents a novel approach to the solution of the one-dimensional transient heat conduction problem applied to ladle linings, relying on classical analytical techniques in combination with numerical methods. The performance of the model was validated by a comparison of predictions to thermocouple measurements from the refractory of a steelmaking ladle during a campaign of 26 casting cycles. Reasonable agreement between the measured and simulated variables could be established, which demonstrates the feasibility of the approach.

  17. Numerical computation of fluid flow in different nonferrous metallurgical reactors

    International Nuclear Information System (INIS)

    Lackner, A.

    1996-10-01

    Heat, mass and fluid flow phenomena in metallurgical reactor systems such as smelting cyclones or electrolytic cells are complex and intricately linked through the governing equations of fluid flow, chemical reaction kinetics and chemical thermodynamics. The challenges for the representation of flow phenomena in such reactors as well as the transfers of these concepts to non-specialist modelers (e.g. plant operators and management personnel) can be met through scientific flow visualization techniques. In the first example the fluid flow of the gas phase and of concentrate particles in a smelting cyclone for copper production are calculated three dimensionally. The effect of design parameters (length and diameter of reactor, concentrate feeding tangentially or from the top, ..) and operating conditions are investigated. Single particle traces show, how to increase particle retention time before the particles reach the liquid film flowing down the cyclone wall. Cyclone separators are widely used in the metallurgical and chemical industry for collection of large quantities of dust. Most of the empirical models, which today are applied for the design, are lacking in being valid in the high temperature region. Therefore the numerical prediction of the collection efficiency of dust particles is done. The particle behavior close to the wall is considered by applying a particle restitution model, which calculates individual particle restitution coefficients as functions of impact velocity and impact angle. The effect of design parameters and operating are studied. Moreover, the fluid flow inside a copper refining electrolysis cell is modeled. The simulation is based on density variations in the boundary layer at the electrode surface. Density and thickness of the boundary layer are compared to measurements in a parametric study. The actual inhibitor concentration in the cell is calculated, too. Moreover, a two-phase flow approach is developed to simulate the behavior of

  18. Effect of CH3COOH on Hydrometallurgical Purification of Metallurgical-Grade Silicon Using HCl-HF Leaching

    Science.gov (United States)

    Tian, Chunjin; Lu, Haifei; Wei, Kuixian; Ma, Wenhui; Xie, Keqiang; Wu, Jijun; Lei, Yun; Yang, Bin; Morita, Kazuki

    2018-04-01

    The present study investigated the effects of adding CH3COOH to HCl and HF used to purify metallurgical-grade Si (MG-Si). After 6 h of leaching MG-Si with an acid mixture consisting of 4 mol L-1 HCl, 3 mol L-1 HF, and 3 mol L-1 CH3COOH at 348 K, the total impurity removal efficiency was 88.5%, exceeding the 81.5% removal efficiency obtained without addition of CH3COOH. The microstructural evolution of Si after etching with the two lixiviants indicated better dissolution of metal impurities in MG-Si when using the HCl-HF-CH3COOH mixture. Furthermore, the leaching kinetics of Fe using the HCl-HF and HCl-HF-CH3COOH mixtures were observed to depend on the interfacial chemical reactions.

  19. Metallurgical sessions. Second ALAMET congress (held in) Buenos Aires, Argentina, 6-10 May 1991

    International Nuclear Information System (INIS)

    1991-01-01

    This congress was held in Buenos Aires, Argentine Republic, on May 6-10, 1991, gathering experts from all over the world. The present volume includes the papers presented at the Metallurgical Sessions - II. ALAMET Congress [es

  20. Development of market strategies of metallurgical enterrprises after restructuring of steel industry

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2014-01-01

    Full Text Available Before metallurgical enterprises started implementation of marketing activities they had to go through restructuring processes which included all areas of their market activities. Privatised metallurgical enterprises after economic transformation gradually implemented marketing to their business activities. The article presents notions connected with development of marketing strategies from the period of last 20 years. The range of analysis includes categories corresponding with instruments of mix marketing (4P − product, price, place, promotion.

  1. USING THE OUTSOURCING MECHANISM TO INCREASE THE EFFICIENCY OF REPAIR AND MAINTENANCE IN METALLURGICAL ENTERPRISES

    OpenAIRE

    Elena I. Kozlova; Anna N. Lopatina; Maxim A. Novak

    2017-01-01

    Abstract. Objectives The aim of the work is to study the outsourcing mechanism from the point of view of increasing the efficiency of repair and maintenance at a metallurgical enterprise. Method Analysis of the experience of using outsourcing of repair services at domestic and foreign metallurgical enterprises was carried out. Analysis of the experience of the withdrawal from enterprise repair services into a separate outsourcing company has shown that the main advantages of this method of or...

  2. Recycling of the rare earth oxides from spent rechargeable batteries using waste metallurgical slags

    Directory of Open Access Journals (Sweden)

    Tang K.

    2013-01-01

    Full Text Available A high temperature process for recycling spent nickel-metal hydride rechargeable batteries has been recently developed at SINTEF/NTNU. The spent battery modules were first frozen with liquid nitrogen for the de-activation and brittle fracture treatment. The broken steel scraps and plastics were then separated by the mechanical classification and magnetic separation. The remaining positive and negative electrodes, together with the polymer separator, were heated to 600-800oC in order to remove the organic components and further separate the Ni-based negative electrode. XRF analyses indicate that the heat-treated materials consist mainly of nickel, rare earth and cobalt oxides. The valuable rare earth oxides were further recovered by the high-temperature slagging treatment. The waste metallurgical slags, consist mainly of SiO2 and CaO, were used as the rare earth oxide absorbent. After the high temperature slagging treatment, over 98% of nickel and cobalt oxides were reduced to the metal phase; meanwhile almost all rare earth oxides remain in the molten slags. Furthermore, EPMA and XRF analyses of the slag samples indicate that the rare earth oxides selectively precipitate in the forms of solid xSiO2•yCaO•zRe2O3. The matrix of slag phase is Re2O3 deficient, typically being less than 5 wt%. This provides a sound basis to further develop the high-temperature process of concentrating the Re2O3 oxides in slags.

  3. NMR investigation of boron impurities in refined metallurgical grade silicon

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, Hans-Joachim; Loeser, Wolfgang; Schmitz, Steffen; Sakaliyska, Miroslava [Leibniz Institute for Solid State and Materials Research (IFW), Dresden (Germany); Wurmehl, Sabine [Leibniz Institute for Solid State and Materials Research (IFW), Dresden (Germany); Institute for Solid State Physics, Technische Universitaet Dresden (Germany); Eisert, Stefan; Reichenbach, Birk; Mueller, Tim [Adensis GmbH, Dresden (Germany); Acker, Joerg; Rietig, Anja; Ducke, Jana [Department of Chemistry, Faculty for Natural Sciences, Brandenburg Technical University Cottbus-Senftenberg, Senftenberg (Germany)

    2015-09-15

    The nuclear magnetic resonance (NMR) method was applied for tracking boron impurities in the refining process of metallurgical grade (MG) silicon. From the NMR signal of the {sup 11}B isotope at an operating temperature 4.2 K, the boron concentration can be estimated down to the order of 1-10 wppm B. After melting and resolidification of MG-Si alloyed with Ca and Ti, a major fraction of B impurities remains in the Si solid solution as inferred from the characteristic NMR frequency. The alloying element Ti does not form substantial fractions of TiB{sub 2}. Acid leaching of crushed powders of MG-Si alloyed with Ca and Ti can diminish the initial impurity content of B suggesting its accumulation in the grain boundary phases. NMR signals of TiB{sub 2} at 4.2 K and room temperature (RT), and of poly-Si with different B doping at 4.2 K. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Fundamental metallurgical aspects of axial splitting in zircaloy cladding

    International Nuclear Information System (INIS)

    Chung, H. M.

    2000-01-01

    Fundamental metallurgical aspects of axial splitting in irradiated Zircaloy cladding have been investigated by microstructural characterization and analytical modeling, with emphasis on application of the results to understand high-burnup fuel failure under RIA situations. Optical microscopy, SEM, and TEM were conducted on BWR and PWR fuel cladding tubes that were irradiated to fluence levels of 3.3 x 10 21 n cm -2 to 5.9 x 10 21 n cm -2 (E > 1 MeV) and tested in hot cell at 292--325 C in Ar. The morphology, distribution, and habit planes of macroscopic and microscopic hydrides in as-irradiated and posttest cladding were determined by stereo-TEM. The type and magnitude of the residual stress produced in association with oxide-layer growth and dense hydride precipitation, and several synergistic factors that strongly influence axial-splitting behavior were analyzed. The results of the microstructural characterization and stress analyses were then correlated with axial-splitting behavior of high-burnup PWR cladding reported for simulated-RIA conditions. The effects of key test procedures and their implications for the interpretation of RIA test results are discussed

  5. Laser treatment of boron carbide surfaces: Metallurgical and morphological examinations

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B.S., E-mail: bsilbas@kfupm.edu.sa; Karatas, C.

    2014-08-01

    Highlights: • Dense layer with fine grains is formed at surface. • Irregular shaped grains and dendrites are formed below dense layer. • Assisting gas forms nitride species (BN and BC{sub 2}N) at surface. • Fracture toughness of treated surface reduces because of high hardness. • Residual stress is compressive and the maximum residual stress is about 0.9 GPa. - Abstract: Laser treatment of B{sub 4}C tile surfaces is carried out under high pressure nitrogen assisting gas environment. Morphological and metallurgical changes in the laser treated layer are examined by incorporating scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction. Microhardness and fracture toughness of the laser treated surface are determined from the indentation data. Residual stress formed at the treated surface is obtained by using X-ray diffraction technique. It is found that laser treated surface is free from large scale asperities including cracks and voids; however, some locally scattered shallow cavities with 1.5–2 μm widths are formed at the surface because of high temperature processing. Dense layer, consisting of fine grains, and formation of nitride species (BN and BC{sub 2}N) enhance microhardness and lower fracture toughness at the surface. Residual stress formed in the treated layer is compressive and the maximum residual stress is in the order of −0.9 GPa.

  6. ECOLOGICAL MANAGEMENT IN THE MINING AND METALLURGICAL MARAMURES AREA

    Directory of Open Access Journals (Sweden)

    Viorel POP

    2015-04-01

    Full Text Available The paper is part of the interdisciplinary recent concerns of "environmental management", looking to determine the damages caused by pollution, remediation expenditures, and benefits that may arise through the application of remediation techniques and decontamination technologies in the mining and metallurgical Maramureş area. Large areas of land were diverted from their original destination (pastures, arable land, forests being now covered with ponds and dumps of mine or flotation tailings, deposits that are insufficiently protected, and have become sources of pollution to surrounding areas. All Eastern European countries have in common major environmental problems, the most serious being due to mining, metallurgy and chemistry. In the relationship of "economic-ecological" equilibrium, should be considered both economic criteria, as well as ecological ones. Pollution as the deterioration of environment, requires costs for rehabilitation of degraded areas, and for environmental protection, costs for new technologies, non polluting ones. The assessment foundation of environmental damages, is necessary for establishing the priority directions in the allocation of funds for projects to protect and rehabilitate the environment.

  7. A metallurgical route to solar-grade silicon

    Science.gov (United States)

    Schei, A.

    1986-02-01

    The aim of the process is to produce silicon for crystallization into ingots that can be sliced to wafers for processing into photovoltaic cells. If the potential purity can be realized, the silicon will also be applicable for ribbon pulling techniques where the purification during crystallization is negligible. The process consists of several steps: selection and purification of raw materials, carbothermic reduction of silica, ladle treatment, casting, crushing, leaching, and melting. The leaching step is crucial for high purity, and the obtainable purity is determined by the solidification before leaching. The most difficult specifications to fulfill are the low contents of boron, phosphorus, and carbon. Boron and phosphorus can be excluded from the raw materials, but the carbothermic reduction will unavoidably saturate the silicon with carbon at high temperature. During cooling carbon will precipitate as silicon carbide crystals, which will be harmful in solar cells. The cost of this solar silicon will depend strongly on the scale of production. It is as yet premature to give exact figures, but with a scale of some thousand tons per year, the cost will only be a few times the cost of ordinary metallurgical silicon.

  8. Assessment and management of ageing of major nuclear power plant components important to safety: Metal components of BWR containment systems

    International Nuclear Information System (INIS)

    2000-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. The guidance reports are directed toward technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific

  9. Bayesian importance parameter modeling of misaligned predictors: soil metal measures related to residential history and intellectual disability in children

    Science.gov (United States)

    Onicescu, Georgiana; Lawson, Andrew B.; McDermott, Suzanne; Aelion, C. Marjorie; Cai, Bo

    2014-01-01

    In this paper, we propose a novel spatial importance parameter hierarchical logistic regression modeling approach that includes measurement error from misalignment. We apply this model to study the relationship between the estimated concentration of soil metals at the residence of mothers and the development of intellectual disability (ID) in their children. The data consist of monthly computerized claims data about the prenatal experience of pregnant women living in nine areas within South Carolina and insured by Medicaid during January 1, 1996 and December 31, 2001 and the outcome of ID in their children during early childhood. We excluded mother-child pairs if the mother moved to an unknown location during pregnancy. We identified an association of the ID outcome with arsenic (As) and mercury (Hg) concentration in soil during pregnancy, controlling for infant sex, maternal race, mother's age, and gestational weeks at delivery. There is some indication that Hg has a slightly higher importance in the third and fourth months of pregnancy, while As has a more uniform effect over all the months with a suggestion of a slight increase in risk in later months. PMID:24888618

  10. Bayesian importance parameter modeling of misaligned predictors: soil metal measures related to residential history and intellectual disability in children.

    Science.gov (United States)

    Onicescu, Georgiana; Lawson, Andrew B; McDermott, Suzanne; Aelion, C Marjorie; Cai, Bo

    2014-09-01

    In this paper, we propose a novel spatial importance parameter hierarchical logistic regression modeling approach that includes measurement error from misalignment. We apply this model to study the relationship between the estimated concentration of soil metals at the residence of mothers and the development of intellectual disability (ID) in their children. The data consist of monthly computerized claims data about the prenatal experience of pregnant women living in nine areas within South Carolina and insured by Medicaid during January 1, 1996 and December 31, 2001 and the outcome of ID in their children during early childhood. We excluded mother-child pairs if the mother moved to an unknown location during pregnancy. We identified an association of the ID outcome with arsenic (As) and mercury (Hg) concentration in soil during pregnancy, controlling for infant sex, maternal race, mother's age, and gestational weeks at delivery. There is some indication that Hg has a slightly higher importance in the third and fourth months of pregnancy, while As has a more uniform effect over all the months with a suggestion of a slight increase in risk in later months.

  11. Laser processing of metals and alloys

    International Nuclear Information System (INIS)

    Goswami, G.L.; Kumar, Dilip; Roy, P.R.

    1988-01-01

    Laser, due to its high degree of coherence can produce powder density in the range of 10 3 -10 11 W/mm 2 . This high power density of the laser beam enables it to be utilized for many industrial applications, e.g. welding, cutting, drilling, surface treatment, etc. Laser processing of materials has many advantages, e.g. good quality product at high processing speed, least heat affected zone, minimum distortion, etc. In addition, the same laser system can be utilized for different applications, a very cost effective factor for any industry. Therefore laser has been adopted for processing of different materials for a wide range of applications and is now replacing conventional materials processing techniques on commercial merits with several economic and metallurgical advantages. Applications of laser to process materials of different thicknesses varying from 0.1 mm to 100 mm have demonstrat ed its capability as an important manufacturing tool for engineering industries. While lasers have most widely been utilized in welding, cutting and drilling they have also found applications in surface treatment of metals and alloys, e.g. transfor mation hardening and annealing. More recently, there has been significant amount of research being undertaken in laser glazing, laser surface alloying and laser cladding for obtaining improved surface properties. This report reviews the stat us of laser processing of metals and alloys emphasising its metallurgical aspects a nd deals with the different laser processes like welding, cutting, drilling and surface treatment highlighting the types and choice of laser and its interaction with metals and alloys and the applications of these processes. (author). 93 refs., 32 figs., 7 tables

  12. Effect of Continuous and Pulsed Current on the Metallurgical and Mechanical Properties of Gas Tungsten Arc Welded AISI 4340 Aeronautical and AISI 304 L Austenitic Stainless Steel Dissimilar Joints

    OpenAIRE

    Arivarasu, Moganraj; Ramkumar Kasinath, Devendranath; Natarajan, Arivazhagan

    2015-01-01

    In this research work, the weldability of low alloyed AISI 4340 aeronautical steel and AISI 304L austenitic stainless steel joined by continuous current (CC) and pulsed current (PC) gas tungsten arc welding (GTAW) techniques, using ER309L and ERNiCr-3 filler metals was investigated. The main focus of the study involves the investigation on the effect of continuous and pulsed current mode of GTA welding process on the metallurgical and mechanical properties of these dissimilar weldments. Micro...

  13. The study of Forest Hara Biosphere Reserve in coast of Persian Gulf and the importance of heavy metal accumulation; Case study: feathers of great cormorant

    Directory of Open Access Journals (Sweden)

    MIR MEHRDAD MIRSANJARI

    2014-11-01

    Full Text Available Mirsanjari MM, Sheybanifar F, Arjmand F. 2014. The study of forest Hara Biosphere Reserve in coast of Persian Gulf and the importance of heavy metal accumulation; Case study: feathers of great cormorant. Nusantara Bioscience 6: 159-164. In recent years, concerns about the long term effects of heavy metals as environmental polluters have arisen, since considerable quantities of heavy metals have been released into the environment as a result of extensive human activities. Heavy metal has been determined as a serious threat to the stability of ecosystems. In this study, we examined the levels of zinc‚ copper‚ lead, and cadmium in the feathers of twenty great cormorants (Phalacrocorax carbo, collected from Hara Biosphere Reserve during November and December in 2012. The results revealed that the mean concentration of heavy metals in the feathers of males is significantly higher than females (P < 0.05. In addition‚ no significant difference was observed in heavy metal concentration between juvenile and adult birds. Moreover, according to the results, the high concentration of heavy metals in some samples indicated this fact that birds are potentially exposed to the risk of heavy metals in their habitat.

  14. Massive production of heavy metals in the Ganga (Hooghly) River estuary, India: Global importance of solute-particle interaction and enhanced metal fluxes to the oceans

    Science.gov (United States)

    Samanta, Saumik; Dalai, Tarun K.

    2018-05-01

    The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.

  15. Quest for steel quality: the role of metallurgical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McLean, A. [Toronto Univ., ON (Canada). Dept. of Metallurgy and Materials Science

    2000-10-01

    Improvements in the quality of steels and the role played by metallurgical chemistry to bring about those improvements are discussed. The particular emphasis is on the chemical behaviour of solutes in molten steel and the reaction between steel, slag and refractory materials and the manner in which they influence the physical properties and performance of the steel product. As an illustration of the contribution of chemistry to steel making the case of the steel plates used in the construction of the Titanic is cited. In 1911 when the Titanic was constructed by Harland and Wolff at their Belfast shipyard, the steel plates used in the hull met all then current specifications. In 1992 when a number of steel samples recovered from the Titanic were examined, it was found that the hull of the vessel was constructed of low carbon, semi-killed steel, produced in the open-hearth process. Microstructural analysis showed extensive carbon banding, typical of hot rolled 0.2 per cent carbon steel. Also found were long manganese sulphide inclusions elongated in the rolling direction, some of which exceeded 25 mm in length. It was determined that as a consequence of these inclusions, at a seawater temperature of 0 degree C, the hull plates of the Titanic had essentially no resistance to fracture. Today's high quality steels used in applications such as Arctic pipelines, offshore platforms, icebreakers and ships for the transportation of natural gas, oxygen and sulphur concentrations are frequently less than 10 ppm. These elements have a profound influence of the quality of the final steel products by virtue of their effect of hindering the formation of inclusions. 2 refs., 3 figs.

  16. Carbones activados con actividad biológica: aplicación en la degradación de compuestos fenólicos procedentes de aguas residuales de la industria metalúrgica de Nobsa–Boyacá / Activated carbon with biological activity: application in the degradation of phenolic compounds from wastewater from metallurgical industry Nobsa-Boyacá.

    OpenAIRE

    Monroy Fonseca, Manuel Alexander

    2010-01-01

    El objetivo del presente trabajo fue unir los dos sistemas, el carbón activado - microorganismos, evaluándolos por separado y con su posible asociación. Los tipos de carbón activado evaluados fueron de origen mineral americano (CAG) y de origen brasilero lignocelulósico (CAP). Los microorganismos fueron aislados de aguas residuales industriales fenólicas de la industria metalúrgica de Nobsa –Boyacá. Se trabajó con concentraciones 50, 100, 200, 300, 500 y 1000 mg/L de fenol para determina...

  17. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution.

    Science.gov (United States)

    Leguédois, Sophie; Van Oort, Folkert; Jongmans, Toine; Chevallier, Pierre

    2004-07-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry lane to a bunker of World War II, temporarily paved with coarse industrial waste fragments and removed at the end of the war. Thin sections made from undisturbed soil samples from A and B horizons were studied. Optical microscopy revealed the occurrence of yellow micrometer-sized (Ap horizon) and red decamicrometer-sized spherulites (AB, B(1)g horizons) as well as distinct distribution patterns. The chemical composition of the spherulites was dominated by Fe, Mn, Zn, Pb, Ca, and P. Comparison of calculated Zn stocks, both in the groundmass and in spherulites, showed a quasi-exclusive Zn accumulation in these neoformed features. Their formation was related to several factors: (i) liberation of metal elements due to weathering of waste products, (ii) Ca and P supply from fertilizing practices, (iii) co-precipitation of metal elements and Ca and P in a porous soil environment, after slow exudation of a supersaturated soil solution in more confined mineral media.

  18. Development and production of cobalt-60 sources for metallurgical application

    International Nuclear Information System (INIS)

    Oliveira, Paulo Fernando; Valente, Eduardo Sarmento; Maretti Junior, Fausto

    2002-01-01

    The CDTN has developed and produced 60 Co sources to be used in level controllers on continuous ingot casting. The sources used in these systems are sealed with a stainless steel revetment and have an useful life equivalent to one half life of the 60 Co (5.272 years). Each system of continuous ingot casting uses a source with one specified activity and different activation section. The sources have been imported with a very high cost due the special shields used to keep and transport them safety. One of its sources, with initial activity of 148 MBq, after being used for more than 5 years in one factory, was given to CDTN to carry out an activation section studies. After these studies be concluded CDTN/CNEN began the procedures to produce a new source in the IPR-R1 TRIGA Reactor, with an irradiation of one cobalt wire in the maximum flux region of the core. The same metallic cobalt wire was irradiated (10% of total activity), to determinate the necessary irradiation time to obtain the final activation. The CDTN developed too a stainless steel recipient with a aluminum nucleus, to seal and to guarantee the integrity of the source. (author)

  19. Metallurgical and mechanical characterization of mild steel-mild ...

    Indian Academy of Sciences (India)

    melting of powder particle and consequently diffusion bonding takes place between the substrate and ... However metallic materials are difficult to get processed with microwave because higher reflection causes ... can be processed in powder form by making metallic powder particle size equal to skin depth. The skin depth ...

  20. Nuclear methods on service of mountain manufacture Navoi Mining-Metallurgical complex

    International Nuclear Information System (INIS)

    Kucherskiy, N.I.

    2004-01-01

    Full text: On a number of the major minerals, such as gold, uranium, copper, tungsten, potash salts, phosphorites, caolines, etc. Uzbekistan on the confirmed stocks and predicted resources occupies leading places among the states of the world. The basic deposits of gold and uranium are concentrated in Central-Kysylkum region, which is field of activity of Navoi mining-metallurgical combine. In industrial divisions of the combine, located in five areas of republic about 60000 persons are engaged. At all stages of manufacture of gold (since investigation) analytical maintenance has extremely important role. In NMMC radioanalytical methods are widely used, in particular, on mine 'Muruntau' the unique gamma-activation analysis laboratory has been constructed and entered into operation. For the period of operation of laboratory, i.e. since 1977, it is executed more than nine millions analyses of geological tests with extremely high expressness (about tens seconds). It is used x-ray-radiometric method for large-portion (by dumper) sortings and on lumpy separation of ores. With the help of high-sensitivity radiometric means of measurements it is possible to develop phosphorites for reception of phosphoric fertilizers. Nuclear-physical methods are applied to the decision of other problems. Thus, due to application of nuclear-physical methods of the operative control of technological processes of mining manufacture, quality management of ores, the account of quantity of products of extraction and their preliminary enrichment, the actual problem - increase in profitability of all mining manufacture NMMC is solved

  1. Groundwater quality assessment plan for the Metallurgical Laboratory Hazardous Waste Management Facility

    Energy Technology Data Exchange (ETDEWEB)

    Jerome, K.M.

    1990-10-01

    The Metallurgical Laboratory Hazardous Waste Management Facility (MLHWMF) will be closed under interim status regulation and permitted as a hazardous waste management facility by a Post Closure Part B Permit under 40 CFR 264. This report discusses the ground water quality assessment plan for the MLHWMF. The Metallurgical Laboratory Hazardous Waste Management Facility consists of the process sewer line leading to the Metallurgical Laboratory basin from the fence, the Metallurgical Laboratory basin, the drainage outfall to the Carolina bay, and the Carolina bay itself. The Metallurgical Laboratory HWMF received F001, F003, F007, and D011 waste. F001 waste includes spent halogenated solvents used in degreasing (trichloroethylene, 1,1,1-trichloroethane, and carbon tetrachloride). F003 waste includes spent nonhalogenated solvents (acetone), and F007 waste is spent cyanide plating bath solution. At present forty-three constituents are analyzed per sample. Trichloroethylene, tetrachloroethylene, and total radium are the only constituents that were reported above Primary Drinking Water Standards (PDWS) during the second quarter of 1990. Listed in this report are the constituents that are being analyzed at present. Appendix A presents the trends for the analyzed constituents from the fourth quarter of 1988 to the second quarter of 1990. 5 figs., 5 tabs.

  2. On dithiothreitol (DTT as a measure of oxidative potential for ambient particles: evidence for the importance of soluble ewline transition metals

    Directory of Open Access Journals (Sweden)

    J. G. Charrier

    2012-10-01

    Full Text Available The rate of consumption of dithiothreitol (DTT is increasingly used to measure the oxidative potential of particulate matter (PM, which has been linked to the adverse health effects of PM. While several quinones are known to be very reactive in the DTT assay, it is unclear what other chemical species might contribute to the loss of DTT in PM extracts. To address this question, we quantify the rate of DTT loss from individual redox-active species that are common in ambient particulate matter. While most past research has indicated that the DTT assay is not sensitive to metals, our results show that seven out of the ten transition metals tested do oxidize DTT, as do three out of the five quinones tested. While metals are less efficient at oxidizing DTT compared to the most reactive quinones, concentrations of soluble transition metals in fine particulate matter are generally much higher than those of quinones. The net result is that metals appear to dominate the DTT response for typical ambient PM2.5 samples. Based on particulate concentrations of quinones and soluble metals from the literature, and our measured DTT responses for these species, we estimate that for typical PM2.5 samples approximately 80% of DTT loss is from transition metals (especially copper and manganese, while quinones account for approximately 20%. We find a similar result for DTT loss measured in a small set of PM2.5 samples from the San Joaquin Valley of California. Because of the important contribution from metals, we also tested how the DTT assay is affected by EDTA, a chelator that is sometimes used in the assay. EDTA significantly suppresses the response from both metals and quinones; we therefore recommend that EDTA should not be included in the DTT assay.

  3. Plasma arc systems for waste treatment and metal recovery

    Science.gov (United States)

    Eschenbach, Richard C.

    1996-06-01

    Plasma torches are being used for treating very difficult wastes,for recovering metal values from metallurgical wastes, and for making high-quality ingots and powder in the special metals industry. This article discusses the process requirements and the state of the art for plasma arc systems in each of these fields.

  4. Interaction Of Hydrogen With Metal Alloys

    Science.gov (United States)

    Danford, M. D.; Montano, J. W.

    1993-01-01

    Report describes experiments on interaction of hydrogen with number of metal alloys. Discusses relationship between metallurgical and crystallographic aspects of structures of alloys and observed distributions of hydrogen on charging. Also discusses effect of formation of hydrides on resistances of alloys to hydrogen. Describes attempt to correlate structures and compositions of alloys with their abilities to resist embrittlement by hydrogen.

  5. Stiffness management of sheet metal parts using laser metal deposition

    Science.gov (United States)

    Bambach, Markus; Sviridov, Alexander; Weisheit, Andreas

    2017-10-01

    Tailored blanks are established solutions for the production of load-adapted sheet metal components. In the course of the individualization of production, such semi-finished products are gaining importance. In addition to tailored welded blanks and tailored rolled blanks, patchwork blanks have been developed which allow a local increase in sheet thickness by welding, gluing or soldering patches onto sheet metal blanks. Patchwork blanks, however, have several limitations, on the one hand, the limited freedom of design in the production of patchwork blanks and, on the other hand, the fact that there is no optimum material bonding with the substrate. The increasing production of derivative and special vehicles on the basis of standard vehicles, prototype production and the functionalization of components require solutions with which semi-finished products and sheet metal components can be provided flexibly with local thickenings or functional elements with a firm metallurgical bond to the substrate. An alternative to tailored and patchwork blanks is, therefore, a free-form reinforcement applied by additive manufacturing via laser metal deposition (LMD). By combining metal forming and additive manufacturing, stiffness can be adapted to the loads based on standard components in a material-efficient manner and without the need to redesign the forming tools. This paper details a study of the potential of stiffness management by LMD using a demonstrator part. Sizing optimization is performed and part distortion is taken into account to find an optimal design for the cladding. A maximum stiffness increase of 167% is feasible with only 4.7% additional mass. Avoiding part distortion leads to a pareto-optimal design which achieves 95% more stiffness with 6% added mass.

  6. Conceptual design for treatment of mining and metallurgical wastewaters which contains arsenic and antimony

    Directory of Open Access Journals (Sweden)

    Željko Kamberović

    2012-12-01

    Full Text Available This paper presents a preliminary design for treatment of mining and metallurgical wastewaters (MMW from the basin of antimony “Zajača“, which contains high concentrations of arsenic and antimony. MMW have been investigated in laboratory, due to large difference in concentrations of pollutants. Metallurgical wastewaters were treated using iron (II-sulfate and lime milk used to adjust the pH value at 7. After chemical treatment of metallurgical wastewater and its joining with mining wastewater, residual amount of arsenic in water was below maximum allowed concentrations, while the concentration of antimony, remained above the maximum allowed value. The final phase of purification process was performed using ion exchange resin. After treatment of MMW, they can be used as technical water in the smelting process of secondary raw lead materials.

  7. ORNL evaluation of the ORR-PSF metallurgical experiment and blind test

    International Nuclear Information System (INIS)

    Stallmann, F.W.

    1984-01-01

    A methodology is described to evaluate the dosimetry and metallurgical data from the two-year ORR-PSF metallurgical irradiation experiment. The first step is to obtain a three-dimensional map of damage exposure parameter values based on neutron transport calculations and dosimetry measurements which are obtained by means of the LSL-M2 adjustment procedure. Metallurgical test data are then combined with damage parameter, temperature, and chemistry information to determine the correlation between radiation and steel embrittlement in reactor pressure vessels including estimates for the uncertainties. Statistical procedures for the evaluation of Charpy data, developed earlier, are used for this investigation. The data obtained in this investigation provide a benchmark against which the predictions of the PSF Blind Test can be compared. The results of this investigation and the Blind Test comparison are discussed

  8. Powder metallurgical high performance materials. Proceedings. Volume 3: general topics

    International Nuclear Information System (INIS)

    Kneringer, G.; Roedhammer, P.; Wildner, H.

    2001-01-01

    The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

  9. Caracterização química de resíduos da indústria metalúrgica para fins de uso agrícola / Chemical characterization of residues of the metallurgic industry for agricultural use

    Directory of Open Access Journals (Sweden)

    Rafael Montanari

    2008-01-01

    Full Text Available Os órgãos de licenciamento ambiental têm se preocupado de modoespecial com os impactos negativos da aplicação de resíduos industriais no meio ambiente. Dentro desse contexto, realizou-se este trabalho,com o objetivo de se estudar os produtos: escória do forno cubilô(EFC, e resíduos de ciclone do sistema de areia (CSA e do ciclone dos desmoldadores (CD, originados de uma indústria metalúrgica, quanto a sua viabilidade de utilização para fins agrícolas. Esse estudo foi motivado pela preocupação com a possibilidade de contaminação do meio ambiente e também pelo elevado requisito de área para destino final desse resíduo. Os teores de elementos possivelmente tóxicos estão abaixo dos limites estabelecidos pela CETESB, possibilitando, assim, o uso agrícola desses resíduos. Dentre os materiais estudados, apenas o EFC apresentou potencial como corretivo de acidez dos solos. Os três materiais analisados apresentaram potencial de atuar como fontes de micronutrientes às plantas.

  10. Physiological and proteomic changes suggest an important role of cell walls in the high tolerance to metals of Elodea nuttallii.

    Science.gov (United States)

    Larras, Floriane; Regier, Nicole; Planchon, Sébastien; Poté, John; Renaut, Jenny; Cosio, Claudia

    2013-12-15

    Macrophytes bioaccumulate metals, the suggestion being made that they be considered for phytoremediation. However, a thorough understanding of the mechanisms of metal tolerance in these plants is necessary to allow full optimization of this approach. The present study was undertaken to gain insight into Hg and Cd accumulation and their effects in a representative macrophyte, Elodea nuttallii. Exposure to methyl-Hg (23 ng dm(-3)) had no significant effect while inorganic Hg (70 ng dm(-3)) and Cd (281 μg dm(-3)) affected root growth but did not affect shoots growth, photosynthesis, or antioxidant enzymes. Phytochelatins were confirmed as having a role in Cd tolerance in this plant while Hg tolerance seems to rely on different mechanisms. Histology and subcellular distribution revealed a localized increase in lignification, and an increased proportion of metal accumulation in cell wall over time. Proteomics further suggested that E. nuttallii was able to efficiently adapt its energy sources and the structure of its cells during Hg and Cd exposure. Storage in cell walls to protect cellular machinery is certainly predominant at environmental concentrations of metals in this plant resulting in a high tolerance highlighted by the absence of toxicity symptoms in shoots despite the significant accumulation of metals. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Mixing and settling in continuous metal production

    International Nuclear Information System (INIS)

    Richter, H.J.; Laaspere, J.T.; Fitzpatrick, J.M.

    1993-01-01

    Modern metallurgical processes produce metal from ore in a single converter operated in horizontal mode to permit staging of bath and oxygen potential by utilizing bottom-blowing of oxygen and fuel. The submerged injectors must create sufficient turbulence to provide excellent gas-liquid contact in order to maximize heat and mass transfer in the bath, but this turbulence must be selectively localized so as to provide adequate phase separation zones of metal and slag between the active turbulent zones. It is important to know the behavior of gas and liquids in the bubble plume, the nature and paths of liquids and entrainment into the plume, and separation phenomena including travel and behavior in the settling zones. Such knowledge is of fundamental value in designing reactors for continuous direct metal making. In this work the mixing caused by submerged injection of gas into a bath simulating a converter and subsequent phase separation of two immiscible liquids representing slag and metal respectively, are being studied experimentally and analytically. First results of experiments and of the numerical analysis are presented

  12. Reconstructing the ecological impacts of eight decades of mining, metallurgical, and municipal activities on a small boreal lake in northern Canada.

    Science.gov (United States)

    Doig, Lorne E; Schiffer, Stephanie T; Liber, Karsten

    2015-07-01

    As a result of long-term metal mining and metallurgical activities, the sediment of Ross Lake (Flin Flon, MB, Canada) is highly contaminated with metals and other elements. Although the effluents likely were discharged into Ross Lake as early as the late 1920s, lake biophysical data were not collected until 1973, more than 4 decades after the onset of mining and municipal activities. The early influence of these activities on the ecology of Ross Lake is unknown, as are the effects of improvements to metallurgical effluent quality and discontinuation of municipal wastewater discharge into the lake's north basin. To address this knowledge gap, analyses typical of paleolimnological investigations were applied to cores of sediment collected in 2009 from the south basin of Ross Lake. Stratigraphic analyses of physicochemical sediment characteristics (e.g., the concentrations of metals and other elements, organic C, total N, and δ(13)C and δ(15)N values) and subfossil remains (diatoms, Chironomidae, Chaoborus, and Cladocera) were used to infer historical biological and chemical changes in Ross Lake. With the onset of mining activities, concentrations of various elements (e.g., As, Cr, Cu, Zn, and Se) increased dramatically in the sediment profile, eventually declining with improved tailings management. Nevertheless, concentrations of metals in recent sediments remain elevated compared with pre-industrial sediments. Constrained cluster analyses demonstrated distinct pre-industrial and postindustrial communities for both the diatoms and chironomids. The biodiversity of the postindustrial diatom assemblages were much reduced compared with the pre-industrial assemblages. The postindustrial chironomid assemblage was dominated by Chironomus and to a lesser extent by Procladius, suggesting that Ross Lake became a degraded environment. Abundances of Cladocera and Chaoborus were severely reduced in the postindustrial era, likely because of metals toxicity. Overall, improvements

  13. Retail optimization in Romanian metallurgical industry by applying of fuzzy networks concept

    Directory of Open Access Journals (Sweden)

    Ioana Adrian

    2017-01-01

    Full Text Available Our article presents possibilities of applying the concept Fuzzy Networks for an efficient metallurgical industry in Romania. We also present and analyze Fuzzy Networks complementary concepts, such as Expert Systems (ES, Enterprise Resource Planning (ERP, Analytics and Intelligent Strategies (SAI. The main results of our article are based on a case study of the possibilities of applying these concepts in metallurgy through Fuzzy Networks. Also, it is presented a case study on the application of the FUZZY concept on the Romanian metallurgical industry.

  14. Comparison of Metallurgical and Ultrasonic Inspections of Galvanized Steel Resistance Spot Welds

    International Nuclear Information System (INIS)

    Potter, Timothy J.; Ghaffari, Bita; Mozurkewich, George; Reverdy, Frederic; Hopkins, Deborah

    2006-01-01

    Metallurgical examination of galvanized steel resistance spot welds was used to gauge the capabilities of two ultrasonic, non-destructive, scanning techniques. One method utilized the amplitude of the echo from the weld faying surface, while the other used the spectral content of the echo train to map the fused area. The specimens were subsequently sectioned and etched, to distinguish the fused, zinc-brazed, and non-fused areas. The spectral maps better matched the metallurgical maps, while the interface-amplitude method consistently overestimated the weld size

  15. Restoration in a mining and metallurgical industries area as a model project. Subproject 1: Factory for amalgamation Halsbruecke. Final report; Modellhafte Sanierung in einer Region mit Bergbau- und Huettenindustrie. Teilvorhaben 1: Amalgamierwerk Halsbruecke, Land Sachsen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Cichos, C.; Menzer, V.; Schaal, A.

    1993-06-01

    Technology development for the restoration of a metallurgical site contaminated by heavy metals (Pb, Zn, Cu, Hg, As) with the aims of far-reaching recycling as well as minimizing of residues and demonstration of this technology contains in a first step - detailed historical exploration; - chemical, physical and mineralogical materials analysis; - bench scale investigations for process engineering. Starting from historical appraisal and geogene/anthropogene conditions the methods of material characterization bring statements on processing of noxious materials (metallurgical), harmless dumping abilities (immobilization, stabilization) and technological process stages (particularly wet mechanical processes). The same methodology is useful for analogous mining, metallurgical and used material sites with contamination by heavy metals and consisting of heterogeneous materials. (orig.) [Deutsch] Die modellhafte Technologieentwicklung und die Demonstration dieser Technologie zur Sanierung eines durch Schwermetalle (Pb, Zn, Cu, Cd, Hg, As) komplex belasteten Huettenstandortes unter dem Aspekt einer weitgehenden Reststoffverwertung sowie Minimierung der zu entsorgenden Rueckstaende umfasst in der ersten Phase - eine detaillierte historische Analyse/Erkundung; - eine chemische, physikalische und mineralogische Stoffcharakterisierung; verfahrenstechnische Untersuchungen im Labormassstab. Ausgehend von der historischen Bewertung und der geogenen/anthropogenen Verhaeltnisse fuehren die Methoden der Stoffcharakterisierung zu Aussagen der Schadstoffweiterverarbeitung (metallurgisch) sowie der gefahrlosen Deponierung (Immobilisierung, Stabilisierung) und zu technologischen Verfahrensschritten (bes. nassmechanische Verfahren). Die Herangehensweise ist fuer analoge Bergbau- aber besonders Huettenstandorte ggf. auch fuer andere Altlastenstandorte mit komplexer Schwermetallkontamination und heterogenem Material relevant. (orig.)

  16. Evidence of trace element emission during the combustion of sulfide-bearing metallurgical slags

    International Nuclear Information System (INIS)

    Bortnikova, Svetlana Borisovna; Olenchenko, Vladimir Vladimirovich; Gaskova, Olga Lukinichna; Chernii, Konstantin Ivanovich; Devyatova, Anna Yurevna; Kucher, Dmitrii Olegovich

    2017-01-01

    The present study shows the results of field and laboratory studies of trace element transfer from waste heaps of metallurgical slags (Kemerovo region, town of Belovo). Temperature anomalies were observed, with high temperatures up to 81.2 °C on the top of the heap. A visual geophysical model of the inner parts of the heap with contrasting resistivity zones was obtained using the electrical resistivity tomography (ERT) method, and quantitative characteristics were derived. Dry and frozen slag zones were characterized by resistivity of 50–500 Ohm·m. The resistivity of wet slag varied from 5 to 10 Ohm·m for slag with low humidity of 1–2 Ohm·m for slag saturated with highly mineralized solutions. The local anomaly of extremely low resistivity (0.3–0.5 Ohm·m) might be associated with a combustion centre or high pore solutions TDS. Basic major elements (Ca, Mg, K, Na, Si, and Al), metals (Cu, Zn, Pb, and Cd) and anionic elements (As, Sb, and V) were determined in gas condensates in situ. The most volatile elements were basic elements: Ca > Cu > Mg > Na > Mn > Fe, Zn. Lower concentration in the condensates was determined for Si > K > As > Sr > Al > V and Pb, Ba, La were also found. The observed mineral paragenetic sequences were primary minerals of barite-polymetallic ores and sphalerite concentrate, high-temperature minerals formed during pyrometallurgical processing and/or permanent combustion of the heap surface, efflorescence minerals formed by atmospheric oxidation accelerated by acid steam condensation. An experimental investigations using stepwise and 500 °C heating of the same samples were performed to compare the elements that were released into the gas phase in situ and off-site. - Highlights: • Sulfide tailings temperature anomalies up to 81.2 °C. • A visual geophysical model of the bowels of the heap with contrasting resistivity zones was obtained. • Base rock-forming elements, metals and anionogenic elements were

  17. On the Beneficial Role of Silicon to Organisms : A Case Study on the Importance of Silicon Chemistry to Metal Accumulation in Yeast

    NARCIS (Netherlands)

    Brasser, H.J.; Krijger, G.C.; Wolterbeek, H.T.

    2008-01-01

    Silicon is involved in numerous important structural and functional roles in a wide range of organisms, including diatoms, plants, and humans, but clear mechanisms have been discovered only in diatoms and sponges. Silicate availability influences metal concentrations within various cell- and

  18. Metallurgical Bonding Development of V-4Cr-4Ti Alloy for the DIII-D Radiative Divertor Program

    International Nuclear Information System (INIS)

    Smith, J.P.; Johnson, W.R.; Trester, P.W.

    1998-01-01

    General Atomics (GA), in conjunction with the Department of Energy's (DOE) DIII-D Program, is carrying out a plan to utilize a vanadium alloy in the DIII-D tokamak as part of the DIII-D Radiative Divertor (RD) upgrade. The V-4Cr-4Ti alloy has been selected in the U.S. as the leading candidate vanadium alloy for fusion applications. This alloy will be used for the divertor fabrication. Manufacturing development with the V-4Cr-4Ti alloy is a focus of the DIII-D RD Program. The RD structure, part of which will be fabricated from V-4Cr-4Ti alloy, will require many product forms and types of metal/metal bonded joints. Metallurgical bonding methods development on this vanadium alloy is therefore a key area of study by GA. Several solid state (non-fusion weld) and fusion weld joining methods are being investigated. To date, GA has been successful in producing ductile, high strength, vacuum leak tight joints by all of the methods under investigation. The solid state joining was accomplished in air, i.e., without the need for a vacuum or inert gas environment to prevent interstitial impurity contamination of the V-4Cr-4Ti alloy

  19. Importance of background values in assessing the impact of heavy metals in river ecosystems: case study of Tisza River, Serbia.

    Science.gov (United States)

    Štrbac, Snežana; Kašanin Grubin, Milica; Vasić, Nebojša

    2017-11-30

    The main objective of this paper is to evaluate how a choice of different background values may affect assessing the anthropogenic heavy metal pollution in sediments from Tisza River (Serbia). The second objective of this paper is to underline significance of using geochemical background values when establishing quality criteria for sediment. Enrichment factor (EF), geoaccumulation index (I geo ), pollution load index (PLI), and potential ecological risk index (PERI) were calculated using different background values. Three geochemical (average metal concentrations in continental crust, average metal concentrations in shale, and average metal concentrations in non-contaminated core sediment samples) and two statistical methods (delineation method and principal component analyses) were used for calculating background values. It can be concluded that obtained information of pollution status can be more dependent on the use of background values than the index/factor chosen. The best option to assess the potential river sediment contamination is to compare obtained concentrations of analyzed elements with concentrations of mineralogically and texturally comparable, uncontaminated core sediment samples. Geochemical background values should be taken into account when establishing quality criteria for soils, sediments, and waters. Due to complexity of the local lithology, it is recommended that environmental monitoring and assessment include selection of an appropriate background values to gain understanding of the geochemistry and potential source of pollution in a given environment.

  20. Estudo comparativo de exames audiométricos de metalúrgicos expostos a ruído e ruído associado a produtos químicos Comparative study of audiometrics tests on metallurgical workers exposed to noise only as well as noise associated to the handling of chemical products

    Directory of Open Access Journals (Sweden)

    Carla Tomaz Botelho

    2009-02-01

    Full Text Available A exposição a produtos químicos ototóxicos na presença ou não do ruído pode provocar danos irreversíveis na audição dos trabalhadores em um período significativamente menor de exposição. OBJETIVO: Realizar um estudo comparativo, através de exames audiométricos, em trabalhadores expostos somente a ruído e ruído associado a produtos químicos. MÉTODOS: 155 metalúrgicos (18 - 50 anos expostos a ruído (grupo I e a ruído e produtos químicos (grupo II por um período que varia de 3 a 20 anos. RESULTADOS: diferença significativa na proporção de perda auditiva ocupacional da orelha direita entre os grupos I (3,6% e II (15,5%. Proporção de perda auditiva ocupacional no profissional significativamente maior no grupo II (18,3% em relação ao grupo I (6%. Com respeito ao tempo médio de exposição aos agentes agressores, o grupo I esteve exposto por tempo significativamente maior. Estudo retrospectivo. DISCUSSÃO: O fato de ter havido maior comprometimento da orelha direita no grupo II é controverso e merece ser pesquisado futuramente, pois alguns estudos revelam que a orelha esquerda seria mais suscetível à lesão por ruído. CONCLUSÃO: O grupo II apresentou proporcionalmente maior prevalência de perda auditiva quando comparado ao grupo I, mesmo tendo estado exposto aos agentes agressores por um menor tempo médio.Exposure to ototoxic chemical products in the presence or absence of noise can cause irreversible injury to the hearing of workers for a significantly short period of exposure period. AIM: to perform a comparative study, through audiometric tests, in workers exposed to noise only and noise associated with chemical products. MATERIALS AND METHODS:155 steel workers (18 - 50 years exposed to noise (group I, and exposed to noise and chemical products (group II for a period that varies from 3 to 20 years. RESULTS: significant difference in the rate of occupational hearing loss in the right ear between groups I (3

  1. Feasibility of metallurgical waste encapsulation in a clay formed matrix

    International Nuclear Information System (INIS)

    Juhnevica, I; Kucinska, J; Sardiko, A; Mezinskis, G

    2011-01-01

    As a result of Joint Stock Company 'Liepajas Metalurgs' production process there are produced certain quantity of substances that are harmful for environment and have to be encapsulated into stable structures. Company's target is modification of these substances into products that form stable compounds in order to avoid metal release in environment. Geopolymers can be synthesized from many materials with a high concentration of aluminosilicates such as metakaolin or fly ash. Heavy metal immobilization in geopolymeric structures is not thought to be caused by physical encapsulation alone, but also through adsorption of the metal ions into the geopolymer structure and possibly even bonding of the metal ions into the structure. All samples have been analyzed with X-Ray, FTIR spectroscopy; chemical analysis and compressive strength tests have been performed. Chemical analysis of geopolymeric samples shows that the main component leached from samples during the boiling in water is Na 2 O that can be explained by more alkaline components nature – Na 2 SiO 3 , NaOH, and SO 3 . Fe 2 O 3 and ZnO are not detected in water extracts at all samples.

  2. Properties and reactions of manganese methylene complexes in the gas phase. The importance of strong metal: carbene bonds for effective olefin metathesis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, A.E.; Beauchamp, J.L.

    1979-10-10

    In this communication the formation, properties and reactions of the gas phase carbenes MnCH/sub 2//sup +/, (CO)/sub 5/MnCH/sub 2//sup +/, and (CO)/sub 4/MnCH/sub 2//sup +/ are described. Reported results include observation of metathesis and abstraction reactions of the methylene ligand with olefins and the first experimental determination of metal-carbene bond dissociation energies. Important points are that: (a) metal-methylene bond energies are extremely strong; and (b) the Mn/sup +/-methylene bond energy is decreased substantially on addition of five carbonyls to the metal center. If the metal-carbene bond energy exceeds 100 kcal/mol, then transfer of the carbene to an olefin to give a cyclopropane or new olefin will be endothermic and thus will not compete with the metathesis reaction. In order to avoid low turnover numbers resulting from consumption of carbene intermediates, strong metal-carbene bonds are a desirable feature of practical metathesis catalysts. (DP)

  3. Recognition of the importance of geogenic sources in the content of metals in PM2.5 collected in the Mexico City Metropolitan Area.

    Science.gov (United States)

    Morton-Bermea, Ofelia; Garza-Galindo, Rodrigo; Hernández-Álvarez, Elizabeth; Amador-Muñoz, Omar; Garcia-Arreola, Maria Elena; Ordoñez-Godínez, Sara L; Beramendi-Orosco, Laura; Santos-Medina, Graciela L; Miranda, Javier; Rosas-Pérez, Irma

    2018-01-17

    The study of airborne metals in urban areas is relevant due to their toxic effects on human health and organisms. In this study, we analyzed metals including rare earth elements (REE) in particles smaller than 2.5 μm (PM 2.5 ), collected at five sites around the Mexico City Metropolitan Area (MCMA), during three periods in 2011: April (dry-warm season, DW), August (rainy season, R), and November (dry-cold season, DC). Principal component analysis allowed identifying factors related to geogenic sources and factors related to anthropogenic sources. The recognition of the high impact of geogenic sources in PM 2.5 is in agreement with the REE distribution patterns, which show similar behavior as those shown by igneous rocks, confirming the influence of the regional geogenic material. Metals associated to geogenic sources showed higher concentration (p  0.05) and no similar seasonal pattern among them. These unexpected results exposed outstanding information regarding the identification of different geogenic sources as the main contributors of metals in the atmospheric environment in the MCMA and highlighted the importance of meteorology in the spatial and seasonal metal patterns.

  4. How simple is too simple? Computational perspective on importance of second-shell environment for metal-ion selectivity

    Czech Academy of Sciences Publication Activity Database

    Gutten, Ondrej; Rulíšek, Lubomír

    2015-01-01

    Roč. 17, č. 22 (2015), s. 14393-14404 ISSN 1463-9076 R&D Projects: GA ČR(CZ) GA14-31419S Institutional support: RVO:61388963 Keywords : metal-ion selectivity * metallopeptide * stability constants * theoretical calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.449, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/cp/c4cp04876h

  5. The economic and social dimensions of Romania’s metallurgical industry

    Directory of Open Access Journals (Sweden)

    V. A. Popescu

    2014-01-01

    Full Text Available The purpose of this paper is to enhance the understanding of both the economic and social dimensions belonging to Romania’s metallurgical industry and how they contribute to generating business value. The approach of this subject became of utmost necessity in turbulent times such as the one Romania is facing nowadays.

  6. Metallurgical analysis of a 304L stainless steel canister from the Spent Fuel Test - Climax

    International Nuclear Information System (INIS)

    Weiss, H.; Van Konynenburg, R.A.; McCright, R.D.

    1985-01-01

    Results of a metallurgical examination of a type 304L stainless steel canister that had been used to store spent nuclear fuel in an underground granite formation for about three years are reported. No observable corrosion or cracking were found. The results are applied to waste packages in a potential high level nuclear waste repository in tuff. 10 refs., 9 figs., 2 tabs

  7. Comparison of metallurgical coke and lignite coke for power generation in Thailand

    Science.gov (United States)

    Ratanakuakangwan, Sudlop; Tangjitsitcharoen, Somkiat

    2017-04-01

    This paper presents and compares two alternatives of cokes in power generation which are the metallurgical coke with coke oven gas and the coke from lignite under the consideration of the energy and the environment. These alternatives not only consume less fuel due to their higher heat content than conventional coal but also has less SO2 emission. The metallurgical coke and its by-product which is coke oven gas can be obtained from the carbonization process of coking coal. According to high grade coking coal, the result in the energy attitude is not profitable but its sulfur content that directly affects the emission of SO2 is considered to be very low. On the other hand, the coke produced from lignite is known as it is the lowest grade from coal and it causes the high pollution. Regarding to energy profitability, the lignite coke is considered to be much more beneficial than the metallurgical coke in contrast to the environmental concerns. However, the metallurgical coke has the highest heating value. Therefore, a decision making between those choices must be referred to the surrounding circumstances based on energy and environment as well as economic consideration in the further research.

  8. International competitiveness and marketing practices in the Australian mining and metallurgical industry

    Energy Technology Data Exchange (ETDEWEB)

    Fynmore, R.J.

    1993-12-31

    The paper examines the sources of Australia`s competitive strengths and weaknesses in the mining and metallurgical industry, and goes on to examine minerals marketing practices. A chart compares Australia`s production costs for iron ore, coal, aluminium, copper, gold, zinc and nickel with those of other major producing countries. 1 fig., 2 tabs.

  9. Simulation model for planning metallurgical treatment of large-size billets

    International Nuclear Information System (INIS)

    Timofeev, M.A.; Echeistova, L.A.; Kuznetsov, V.G.; Semakin, S.V.; Krivonogov, A.B.

    1989-01-01

    The computerized simulation system ''Ritm'' for planning metallurgical treatment of billets is developed. Three principles, specifying the organization structure of the treatment cycle are formulated as follows: a cycling principle, a priority principle and a principle of group treatment. The ''Ritm'' software consists of three independent operating systems: preparation of source data, simulation, data output

  10. Quality of some Nigerian coals as a blending stock in metallurgical ...

    African Journals Online (AJOL)

    Lafia- Obi/foreign coals blends possess lower ash and better rheological properties compared to Chikila/foreign coal composites which have high ash and poor rheological properties. These together suggest that amongst the two Nigerian coals, Lafia-Obi is superior for blending with the foreign ones in metallurgical coke ...

  11. Biotechnology in the management and resource recovery from metal bearing solid wastes: Recent advances.

    Science.gov (United States)

    Sethurajan, Manivannan; van Hullebusch, Eric D; Nancharaiah, Yarlagadda V

    2018-04-01

    Solid metalliferous wastes (sludges, dusts, residues, slags, red mud and tailing wastes) originating from ferrous and non-ferrous metallurgical industries are a serious environmental threat, when waste management practices are not properly followed. Metalliferous wastes generated by metallurgical industries are promising resources for biotechnological extraction of metals. These wastes still contain significant amounts of valuable non-ferrous metals, sometimes precious metals and also rare earth elements. Elemental composition and mineralogy of the metallurgical wastes is dependent on the nature of mining site and composition of primary ores mined. Most of the metalliferous wastes are oxidized in nature and contain less/no reduced sulfidic minerals (which can be quite well processed by biohydrometallurgy). However, application of biohydrometallurgy is more challenging while extracting metals from metallurgical wastes that contain oxide minerals. In this review, origin, elemental composition and mineralogy of the metallurgical solid wastes are presented. Various bio-hydrometallurgical processes that can be considered for the extraction of non-ferrous metals from metal bearing solid wastes are reviewed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. PLUTONIUM METAL: OXIDATION CONSIDERATIONS AND APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Estochen, E.

    2013-03-20

    Plutonium is arguably the most unique of all metals when considered in the combined context of metallurgical, chemical, and nuclear behavior. Much of the research in understanding behavior and characteristics of plutonium materials has its genesis in work associated with nuclear weapons systems. However, with the advent of applications in fuel materials, the focus in plutonium science has been more towards nuclear fuel applications, as well as long term storage and disposition. The focus of discussion included herein is related to preparing plutonium materials to meet goals consistent with non-proliferation. More specifically, the emphasis is on the treatment of legacy plutonium, in primarily metallic form, and safe handling, packaging, and transport to meet non-proliferation goals of safe/secure storage. Elevated temperature oxidation of plutonium metal is the treatment of choice, due to extensive experiential data related to the method, as the oxide form of plutonium is one of only a few compounds that is relatively simple to produce, and stable over a large temperature range. Despite the simplicity of the steps required to oxidize plutonium metal, it is important to understand the behavior of plutonium to ensure that oxidation is conducted in a safe and effective manner. It is important to understand the effect of changes in environmental variables on the oxidation characteristics of plutonium. The primary purpose of this report is to present a brief summary of information related to plutonium metal attributes, behavior, methods for conversion to oxide, and the ancillary considerations related to processing and facility safety. The information provided is based on data available in the public domain and from experience in oxidation of such materials at various facilities in the United States. The report is provided as a general reference for implementation of a simple and safe plutonium metal oxidation technique.

  13. Absorption of metals and characterization of chemical elements present in three species of Gracilaria (Gracilariaceae Greville: a genus of economical importance

    Directory of Open Access Journals (Sweden)

    Angela P. Tonon

    2011-04-01

    Full Text Available Gracilaria Greville is a genus of seaweed that is economically explored by the cosmetic, pharmaceutical and food industries. One of the biggest problems associated with growing Gracilaria is the discharge of heavy metals into the marine environment. The absorption of heavy metals was investigated with the macroalga Gracilaria tenuistipitata Zhang et Xia, cultivated in a medium containing copper (Cu and cadmium (Cd. In biological samples, EC50 concentrations of 1 ppm for cadmium and 0.95 ppm for copper were used. These concentrations were based on seaweed growth curves obtained over a period of six days in previous studies. ICP-AES was used to determine the amount of metal that seaweeds absorbed during this period. G. tenuistipitata was able to bioaccumulate both metals, about 17% of copper and 9% of cadmium. Basal natural levels of Cu were found in control seaweeds and in G. tenuistipitata exposed to Cd. In addition, the repertoire of other important chemical elements, as well as their concentrations, was determined for G. tenuistipitata and two other important seaweeds, G. birdiae Plastino & Oliveira and G. domingensis (Kützing Sonder ex Dickie, collected in natural environments on the Brazilian shore.

  14. Metallurgical characterization of brass objects from the Akko 1 shipwreck, Israel

    Energy Technology Data Exchange (ETDEWEB)

    Ashkenazi, D., E-mail: dana@eng.tau.ac.il [Faculty of Engineering, Tel Aviv University, Ramat Aviv 69978 (Israel); Cvikel, D. [Leon Recanati Institute for Maritime Studies, University of Haifa, 31905 (Israel); Stern, A. [Department of Materials Engineering, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Klein, S. [Institut für Geowissenschaften, Facheinheit Mineralogie, J. W. Goethe Universität, Altenhöferallee 1, D-60438 Frankfurt am Main (Germany); Kahanov, Y. [Leon Recanati Institute for Maritime Studies, University of Haifa, 31905 (Israel)

    2014-06-01

    The Akko 1 shipwreck was a small Egyptian armed vessel or auxiliary naval brig built in the eastern Mediterranean at the beginning of the 19th century. During the underwater excavations, about 230 brass hook-and-eye closures were found, mainly in the bow area. In addition, 158 brass cases were found, mainly between midships and the aft extremity of the shipwreck. Metallurgical non-destructive and destructive characterizations of selected items were performed, including radiographic testing, XRF, lead isotope analysis, optical microscopy, SEM–EDS and microhardness tests. The hook-and-eye closures and the cases were both found to be made of binary copper–zinc alloy (about 30 wt.% zinc). While the brass cases were made from rolled sheets, hand-made using simple tools, and joined by tin–lead soldering material, the brass hook-and-eye closures were hand-made from drawn brass wire, and manufactured from commercial drawn brass bars by a cold-working process. The lead isotope analyses suggest different provenances of the raw materials used for making the brass objects, thus the different origins of the ores may hint that the brass wire and sheet were imported to the workshops in which the objects were manufactured. - Highlights: • Brass cases and hook-and-eye closures were retrieved from the Akko 1 shipwreck. • Both types of objects were made of binary copper–zinc alloy (about 30 wt.% zinc). • The cases were hand-made from rolled sheets and joined by tin–lead soldering. • Hook-and-eye closures were made from drawn brass wire manufactured by cold-working. • Lead isotope analyses suggest that the origins of the raw material were diverse.

  15. Metallurgical characterization of brass objects from the Akko 1 shipwreck, Israel

    International Nuclear Information System (INIS)

    Ashkenazi, D.; Cvikel, D.; Stern, A.; Klein, S.; Kahanov, Y.

    2014-01-01

    The Akko 1 shipwreck was a small Egyptian armed vessel or auxiliary naval brig built in the eastern Mediterranean at the beginning of the 19th century. During the underwater excavations, about 230 brass hook-and-eye closures were found, mainly in the bow area. In addition, 158 brass cases were found, mainly between midships and the aft extremity of the shipwreck. Metallurgical non-destructive and destructive characterizations of selected items were performed, including radiographic testing, XRF, lead isotope analysis, optical microscopy, SEM–EDS and microhardness tests. The hook-and-eye closures and the cases were both found to be made of binary copper–zinc alloy (about 30 wt.% zinc). While the brass cases were made from rolled sheets, hand-made using simple tools, and joined by tin–lead soldering material, the brass hook-and-eye closures were hand-made from drawn brass wire, and manufactured from commercial drawn brass bars by a cold-working process. The lead isotope analyses suggest different provenances of the raw materials used for making the brass objects, thus the different origins of the ores may hint that the brass wire and sheet were imported to the workshops in which the objects were manufactured. - Highlights: • Brass cases and hook-and-eye closures were retrieved from the Akko 1 shipwreck. • Both types of objects were made of binary copper–zinc alloy (about 30 wt.% zinc). • The cases were hand-made from rolled sheets and joined by tin–lead soldering. • Hook-and-eye closures were made from drawn brass wire manufactured by cold-working. • Lead isotope analyses suggest that the origins of the raw material were diverse

  16. Magnesite base desulfurizer of metallurgical physical chemistry research

    Directory of Open Access Journals (Sweden)

    G. D. Liu

    2017-01-01

    Full Text Available This topic put carbon thermal vacuum method in combination with magnesium based desulfurization technology with magnesite reduction of magnesium vapor directly on hot metal desulphurization. This is a new type of desulfurization technology, the retrieval related literature at home and abroad was not reported in the recent ten years, according to the relationship between heat of desulfurizer preparation MgO style content can reach 50 %.It was found that the desulfurizer sample with 50 % MgO content was in accordance with the requirements, without adding flux, but its viscosity did not meet the requirements; adding 1 % flux (CaF2, the sample viscosity was significantly reduced, and about 1 400 °C sample viscosity suitable for hot metal pretreatment desulfurization.

  17. Microbiological and physicochemical treatments applied to metallurgic industry aiming water reuse

    Directory of Open Access Journals (Sweden)

    Antonio Roberto Crystal Bello

    2008-04-01

    Full Text Available A study was conducted on the reuse of the water in a system composed of a sewage treatment plant (STP using prolonged aeration with activated sludge and a compact water treatment plant (CWTP in a metallurgic industry. The processes for obtaining the water for reuse were microbiological and physicochemical. The domestic sewage was then pumped to the STP, where biological flocks were formed and clarified water was obtained. The efficiency of the microbiological process in the STP was evaluated for removal of biochemical oxygen demand (BOD, chemical oxygen demand (COD and sedimentary solids (SS. The efficiency of physicochemical processes for clarifying the water and disinfection was evaluated through analysis of pH, turbidity, color, aerobic heterotrophic bacterial count, free chlorine, hardness, alkalinity, chlorides, sulfates and dissolved total solids (DTS. In the reuse of the water, acute toxicity for the microcrustaceans Daphnia similis was also evaluated.Estudou-se o reuso de água de um sistema composto por estação de tratamento de esgoto (ETE com aeração prolongada e lodo ativado, e em uma estação compacta de tratamento de água (ECTA de uma indústria metalúrgica. Os processos para obtenção da água de reuso foram: microbiológico e físico-químico. O esgoto doméstico foi bombeado para a ETE, onde houve formação de flocos biológicos e água clarificada. Avaliou-se a eficiência do processo microbiológico da ETE mediante a remoção de demanda bioquímica de oxigênio (DBO, demanda química de oxigênio (DQO e sólidos sedimentáveis (SS. A eficiência do processo físico-químico de clarificação e desinfecção foi avaliada mediante análises de pH, turbidez, cor, contagem de bactérias heterotróficas aeróbias, cloro livre, dureza, alcalinidade, cloretos, sulfatos, sólidos totais dissolvidos (STD. Na água de reuso além desses parâmetros avaliou-se a toxicidade aguda ao microcrustáceo Daphnia similis.

  18. Development of Experimental Setup of Metal Rapid Prototyping Machine using Selective Laser Sintering Technique

    Science.gov (United States)

    Patil, S. N.; Mulay, A. V.; Ahuja, B. B.

    2018-04-01

    Unlike in the traditional manufacturing processes, additive manufacturing as rapid prototyping, allows designers to produce parts that were previously considered too complex to make economically. The shift is taking place from plastic prototype to fully functional metallic parts by direct deposition of metallic powders as produced parts can be directly used for desired purpose. This work is directed towards the development of experimental setup of metal rapid prototyping machine using selective laser sintering and studies the various parameters, which plays important role in the metal rapid prototyping using SLS technique. The machine structure in mainly divided into three main categories namely, (1) Z-movement of bed and table, (2) X-Y movement arrangement for LASER movements and (3) feeder mechanism. Z-movement of bed is controlled by using lead screw, bevel gear pair and stepper motor, which will maintain the accuracy of layer thickness. X-Y movements are controlled using timing belt and stepper motors for precise movements of LASER source. Feeder mechanism is then developed to control uniformity of layer thickness metal powder. Simultaneously, the study is carried out for selection of material. Various types of metal powders can be used for metal RP as Single metal powder, mixture of two metals powder, and combination of metal and polymer powder. Conclusion leads to use of mixture of two metals powder to minimize the problems such as, balling effect and porosity. Developed System can be validated by conducting various experiments on manufactured part to check mechanical and metallurgical properties. After studying the results of these experiments, various process parameters as LASER properties (as power, speed etc.), and material properties (as grain size and structure etc.) will be optimized. This work is mainly focused on the design and development of cost effective experimental setup of metal rapid prototyping using SLS technique which will gives the feel of

  19. Metallurgical, surface, and corrosion analysis of Ni-Cr dental casting alloys before and after porcelain firing.

    Science.gov (United States)

    Lin, Hsin-Yi; Bowers, Bonnie; Wolan, John T; Cai, Zhuo; Bumgardner, Joel D

    2008-03-01

    A porcelain veneer is often fired on nickel-chromium casting alloys used in dental restorations for aesthetic purposes. The porcelain-fused-to-metal (PFM) process brings the temperature to over 950 degrees C and may change the alloy's corrosion properties. In this study, the metallurgical, surface, and corrosion properties of two Ni-Cr alloys were examined, before and after PFM firing. Two types of alloy were tested-a high Cr, Mo alloy without Be and a low Cr, Mo alloy with Be. Before the PFM firing, specimens from both alloys were examined for their microstructures, hardness, electrochemical corrosion properties, surface composition, and metal ion release. After the PFM firing, the same specimens were again examined for the same properties. Neither of the alloys showed any differences in their electrochemical corrosion properties after the PFM firing. However, both alloys exhibited new phases in their microstructure and significant changes in hardness after firing. In addition, there was a slight increase in CrO(x) on the surface of the Be-free alloy and increased Mo-Ni was observed on the surface of both alloys via X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). This might be one of the reasons why both alloys had increased Ni and Mo ion release after firing. The PFM firing process changed the alloys' hardness, microstructure, and surface composition. No significant changes in the alloys' corrosion behavior were observed, however, the significant increase in metal ion release over a month may need to be further investigated for its clinical effects.

  20. The Importance of Preventive Feedback: Inference from Observations of the Stellar Masses and Metallicities of Milky Way Dwarf Galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yu; Benson, Andrew; Wetzel, Andrew; Tonnesen, Stephanie [The Observatories, The Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Mao, Yao-Yuan [Department of Physics and Astronomy and the Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, Pittsburgh, PA 15260 (United States); Peter, Annika H. G. [CCAPP and Department of Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210 (United States); Boylan-Kolchin, Michael [Department of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2017-09-01

    Dwarf galaxies are known to have remarkably low star formation efficiency due to strong feedback. Adopting the dwarf galaxies of the Milky Way (MW) as a laboratory, we explore a flexible semi-analytic galaxy formation model to understand how the feedback processes shape the satellite galaxies of the MW. Using Markov Chain Monte Carlo, we exhaustively search a large parameter space of the model and rigorously show that the general wisdom of strong outflows as the primary feedback mechanism cannot simultaneously explain the stellar mass function and the mass–metallicity relation of the MW satellites. An extended model that assumes that a fraction of baryons is prevented from collapsing into low-mass halos in the first place can be accurately constrained to simultaneously reproduce those observations. The inference suggests that two different physical mechanisms are needed to explain the two different data sets. In particular, moderate outflows with weak halo mass dependence are needed to explain the mass–metallicity relation, and prevention of baryons falling into shallow gravitational potentials of low-mass halos (e.g., “pre-heating”) is needed to explain the low stellar mass fraction for a given subhalo mass.

  1. Development of the production of lead and precious metals in Central Asia

    Directory of Open Access Journals (Sweden)

    Nikolić Branislav

    2014-01-01

    Full Text Available There were several rich deposits of polymetal ores of non-ferrous and precious metals in the region of Imperial Russia and the Soviet Union. Metallurgical production of these metals was developed even a thousand years ago and was in the top of the world at the beginning of the fourth quarter of the twentieth century. The disintegration of the Soviet Union and the change of government structures caused a reduction of metallurgical production, but there are all conditions to intensify and increase the production of non-ferrous and precious metals in Russia and other former Soviet republics, which are now middle-asian countries.

  2. Carp’s-tongue swords - morphological, metallurgical and cultural aspects

    Directory of Open Access Journals (Sweden)

    Brandherm, Dirk

    2010-12-01

    Full Text Available This contribution discusses the results from a study of the spatial distribution of different morphological sub-groups of carp’s-tongue swords at a European scale, relating morphological types to the metallurgial make-up of the respective pieces. From this study some surprising conclusions concerning the chronological as well as the spatial dimension of the evolution of carp’s-tongue swords emerge. We also look at the degree of variability in the deposition of these artefacts and in the composition of the assemblages in question, with considerable repercussions for our understanding of the depositional contexts of metal objects in the Atlantic Bronze Age world in general.

    Se presentan los resultados de un análisis de la dispersión geográfica de los distintos subgrupos morfológicos de las espadas en lengua de carpa a nivel europeo, poniéndolas en relación con una marcada variabilidad en la composición metalúrgica de estas piezas, que lleva a conclusiones inesperadas sobre la dimensión temporal y espacial de su evolución. El análisis de la variabilidad en los ritos de deposición de estos artefactos y en la composición de los conjuntos en que se encuentran, tiene importantes repercusiones sobre nuestra imagen de los contextos deposicionales de los objetos metálicos en el mundo del Bronce Final atlántico en general.

  3. Development of advanced high strength tantalum base alloys. Phase 3: Influence of metallurgical condition on the mechanical properties of ASTAR-811C sheet

    Science.gov (United States)

    Ammon, R. L.; Buckman, R. W., Jr.; Harrod, D. L.

    1972-01-01

    Metallurgical condition was shown to have a significant effect on the creep properties of ASTAR-811C (Ta-8W-1Re-0.7Hf-0.025C) sheet. Cold worked material exhibited creep rates 30 times higher than solution annealed material and 10 times greater than for recrystallized material. Both grain size and the carbide morphology changes as the final annealing temperature was raised from 3000 F to 3600 F. However, the lowest creep rates were achieved for material which retained the high temperature form of the Ta2C precipitate. Samples with GTA weldments had essentially identical properties as recrystallized base metal. Cooling rates from 3600 F of 5, 50, and 800 F deg/min. had little effect on the 2000 and 2400 F creep behavior of ASTAR-811C.

  4. Metallurgical and mechanical properties of Inconel 600 and stellite; Estudio del comportamiento mecanico-metalurgico de alceacion inconel 600 y estelita

    Energy Technology Data Exchange (ETDEWEB)

    Cstillo, Martin; Villa, Gabriel; Vite, Manuel [Instituto Politecnico Nacional, Mexico D.F. (Mexico); Palacios, Francisco [Instituto Nacional de Investigacion Nuclear (ININ), Estado de Mexico (Mexico); Hernandez, Luis H; Urriolagoita, Guillermo [Instituto Politecnico Nacional, Mexico D.F. (Mexico)

    2005-01-15

    The present work studies the metallurgical and mechanical properties of two alloys, Inconel 600 and stellite, which are within the group of high hardness alloys or superalloys, which are deposited through the electrical weld process to the metallic arc with coated electrode (SMAW) and thereinafter analyzed through electron microscopy, diffractometry and abrasion, Impact and hardness test. The relationship between the microstructure and the final properties of the coating (hardness and abrasion wear resistance) was observed. [Spanish] Este trabajo presenta el estudio sobre las propiedades metalurgicas y mecanicas de dos aleaciones, inconel 600 y estelita, clasificadas dentro del grupo de aleaciones de alta dureza o superaleaciones; las cuales fueron depositadas mediante el proceso de soldadura electrica al arco metalico con electrodo revestido (SMAW) y fueron analizadas mediante microscopia electronica (SEM), difractometria pruebas de abrasion, impacto y dureza. Se observo la relacion entre la microstructura y las propiedades del recubrimiento, como son: dureza, resistencia a la abrasion, resistencia al impacto, ente otras.

  5. Preliminary results on air pollution inside an iron metallurgical plant, using rotating streaker sampler and energy dispersive X-ray microfluorescence

    International Nuclear Information System (INIS)

    Nascimento Filho, V.F.; Silva, R.M.C.; Perez, C.A.

    2005-01-01

    Our aim was to study the chemical concentration of some metals in suspended particulate matter inside an-iron metallurgical plant. Using a rotating streaker air-particulate sampler with 8 and 0.45 microns pore diameter filter, it was possible to collect coarse and fine particulates during a week, with one hour step. After this, each strip of the filter was analyzed by energy dispersive x-ray microfluorescence (μ-EDXRF), using in the excitation a collimated x-ray line beam from a Mo target tube (30 kV, 20 mA, Zr filter) with a quartz capillary (120 mm long, 10 mm entrance diameter and 20 microns inner diameter at exit). The detection was carried out using a Si(Li) semiconductor detector coupled to a multichannel analyzer, and the X-ray spectra were fitted with the AXIL software. The profiles of several elements are shown and the results are discussed.

  6. Long-Term Monitoring Network Optimization Evaluation for Operable Unit 2, Bunker Hill Mining and Metallurgical Complex Superfund Site, Idaho

    Science.gov (United States)

    This report presents a description and evaluation of the ground water and surface water monitoring program associated with the Bunker Hill Mining and Metallurgical Complex Superfund Site (Bunker Hill) Operable Unit (OU) 2.

  7. Detection of contaminated metallurgical scrap at borders: a proposal for an 'investigation level'

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1999-01-01

    In 1995 the IAEA started a program to combat illicit trafficking in nuclear and other radioactive materials which includes the problem of cross-border movement of contaminated metallurgical scrap. A major activity in this program is the elaboration of a Safety Guide on 'Preventing, Detecting and Responding to Illicit Trafficking', co-sponsored by the World Customs Organization (WCO) and INTERPOL. The guide will provide advice to the Member States, in particular on technical and administrative procedures for detection of radioactive materials at borders. Radiation monitoring systems for contaminated scrap metals have been successfully used in steel plants and larger scrap yards since several years and suitable products are on the market today. Using sophisticated software and dynamic scanning techniques such systems allow for detection of an artificial increase in radiation background level as low as by 20%, even if the natural background signal is substantially suppressed by the vehicle itself entering the monitor. However, the measurement conditions at borders are essentially different from those in plants. Large traffic crossing major borders limits the time for detection and response to a few seconds and multiple checks are nearly impractical. Shielded radioactive sources - even of high activity - which are deeply buried in scrap, cannot be detected without unloading the vehicle, a procedure generally ruled out at borders. Highly sensitive monitoring systems necessarily cause frequent false alarms or nuisance alarms due to innocent radioactive materials such as naturally occurring radioactivity e.g. in fertilizers, scale in pipes used in the oil industry or medical radioisotopes. A particular, rather frequent problem is the unnecessary reject of scrap transports on borders due to the inherent low level contamination of steel with 60 Co, even in sheet metal used for lorries or railroad cars. Such contamination can easily be caused by the routine method to control

  8. Bio-processing of solid wastes and secondary resources for metal extraction – A review

    International Nuclear Information System (INIS)

    Lee, Jae-chun; Pandey, Banshi Dhar

    2012-01-01

    Highlights: ► Review focuses on bio-extraction of metals from solid wastes of industries and consumer goods. ► Bio-processing of certain effluents/wastewaters with metals is also included in brief. ► Quantity/composition of wastes are assessed, and microbes used and leaching conditions included. ► Bio-recovery using bacteria, fungi and archaea is highlighted for resource recycling. ► Process methodology/mechanism, R and D direction and scope of large scale use are briefly included. - Abstract: Metal containing wastes/byproducts of various industries, used consumer goods, and municipal waste are potential pollutants, if not treated properly. They may also be important secondary resources if processed in eco-friendly manner for secured supply of contained metals/materials. Bio-extraction of metals from such resources with microbes such as bacteria, fungi and archaea is being increasingly explored to meet the twin objectives of resource recycling and pollution mitigation. This review focuses on the bio-processing of solid wastes/byproducts of metallurgical and manufacturing industries, chemical/petrochemical plants, electroplating and tanning units, besides sewage sludge and fly ash of municipal incinerators, electronic wastes (e-wastes/PCBs), used batteries, etc. An assessment has been made to quantify the wastes generated and its compositions, microbes used, metal leaching efficiency etc. Processing of certain effluents and wastewaters comprising of metals is also included in brief. Future directions of research are highlighted.

  9. Characterization of tool wear in high-speed milling of hardened powder metallurgical steels

    OpenAIRE

    Klocke, Fritz; Arntz, Kristian; Cabral, Gustavo Francisco; Stolorz, Martin; Busch, Marc

    2011-01-01

    In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC) and the high speed steel HS 6-5-3 PM (S790...

  10. Metallurgical Characterization of Reduced Activation Martensitic Steel F-82H Modified

    International Nuclear Information System (INIS)

    Fernandez, P.; Lapena, J.; Lancha, A.M.; Gomez-Briceno, D.; Schirra, M.

    1999-12-01

    During 1995-1998 within of research and development programs on reduced ferritic/martensitic steels for fusion, metallurgical characterization of 8Cr-2WVTa steel, denominated F-28H modified, have been carried out. The work has focused on studying the microstructural and mechanical (tensile, creep, low cycle fatigue and charpy) characteristics of as-received state and aged material in the temperature range 300 degree centigrade to 600 degree centigrade for periods up to 5000 h. (Author) 45 refs

  11. Metallurgical bond between magnesium AZ91 alloy and aluminium plasma sprayed coatings

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Pala, Zdeněk; Neufuss, Karel; Vilémová, Monika; Mušálek, Radek; Stoulil, J.; Slepička, P.; Chráska, Tomáš

    2015-01-01

    Roč. 282, November (2015), s. 163-170 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : Plasma spraying * AZ91 magnesium alloy * Aluminium * Metallurgical bond * X-ray diffraction Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.139, year: 2015 http://www.sciencedirect.com/science/article/pii/S0257897215303297

  12. Graduates mining and metallurgical specialty in professional and economic spheres of society (Dnepropetrovsk region)

    OpenAIRE

    M. V. Mosondz

    2015-01-01

    The paper analyzes the process of inclusion graduates of mining and metallurgical complex (MMC) to professional and economic spheres of society; attitude of employers to hire graduates; barriers to hiring young professionals; evaluation indicators of successful graduates of vocational integration. Revealed a rather high level of professional work (64%); positive assessment of the benefits of education; greatest satisfaction such conditions as stable income, matching specialty; insufficient...

  13. Metallurgical flow recognition by random signal analysis of stress wave emissions

    International Nuclear Information System (INIS)

    Woodward, B.

    1973-01-01

    The present study involves detailed random signal analysis of individual 'bursts' of emission with objective of 'reading' their frequency spectra to identify specific metallurgical mechanisms. Mild steel unnotched testpieces were used in the early stages of development of this research. From a fracture mechanics point of view this research could lead to a powerful nondestructive testing device allowing identification of interior, instead of only surface, deformation mechanisms. (author)

  14. Effect of friction time on mechanical and metallurgical properties of continuous drive friction welded Ti6Al4V/SUS321 joints

    International Nuclear Information System (INIS)

    Li, Peng; Li, Jinglong; Salman, Muhammad; Liang, Li; Xiong, Jiangtao; Zhang, Fusheng

    2014-01-01

    Highlights: • The effect of friction time on the microstructure and joint strength was studied. • The fit of burn-off lengths at different times yields a simple equation. • The longer friction time leads to oversized flash in Ti6Al4V side and overgrown IMCs. • An IMZ with width less than 3 μm is beneficial to make a strong metallurgical bond. • The average strength of 560 MPa is obtained and higher than ever reported results. - Abstract: Dissimilar joint of Ti6Al4V titanium alloy and SUS321 stainless steel was fabricated by continuous drive friction welding. The effect of friction time on the mechanical properties was evaluated by hardness measurement and tensile test, while the interfacial microstructure and fracture morphologies were analyzed by scanning electron microscope, energy dispersive spectroscope and X-ray Diffraction. The results show that the tensile strength increases with friction time under the experimental conditions. And the maximum average strength 560 MPa, which is 90.3% of the SUS321 base metal, is achieved at a friction time of 4 s. For all samples, studied fracture occurred along the joint interface, where intermetallic compounds like FeTi, Fe 2 Ti, Ni 3 (Al, Ti) and Fe 3 Ti 3 O and many other phases were formed among elements from the two base metals. The width of intermetallic compounds zone increases with friction time up to 3 μm, below which it is beneficial to make a strong metallurgical bond. However, the longer friction time leads to oversized flash on the Ti6Al4V side and overgrown intermetallic compounds. Finally the optimized friction time was discussed to be in the range of 2–4 s, under which the sound joint with good reproducibility can be expected

  15. Metals content of Glossoscolex paulistus extracellular hemoglobin: Its peroxidase activity and the importance of these ions in the protein stability.

    Science.gov (United States)

    Caruso, Celia S; Biazin, Ezer; Carvalho, Francisco A O; Tabak, Marcel; Bachega, José F R

    2016-08-01

    In this work we investigate the presence of divalent cations bound to the Glossoscolex paulistus (HbGp) hemoglobin and their effect over the protein stability and the peroxidase (POD) activity. Atomic absorption studies show that the HbGp iron content is consistent with the presence of 144 ions per protein. Moreover, using iron as a reference, the content of calcium was estimated as 30±4 ions per protein, independently of the EDTA pre-treatment or not prior to the acidic treatment performed in the protein digestion. The zinc content was 14±2 ions in the absence of EDTA pre-treatment, and 3±1 ions per protein in the presence of EDTA pre-treatment, implying the presence of one zinc ion per protomer (1/12 of the whole molecule). Finally, the copper concentration is negligible. Different from the vertebrate hemoglobins, where the effectors are usually organic anions, the hexagonal bilayer hemoglobins have as effectors inorganic cations that increase the oxygen affinity and stabilize the structure. Previous studies have suggested that the presence of divalent cations, such as copper and zinc, is related to the different types of antioxidant enzymatic activities as the superoxide dismutase (SOD) activity shown by giant hemoglobin from Lumbricus terrestris (HbLt). Recently, studies on HbGp crystal structure have confirmed the presence of Zn(2+) and Ca(2+) binding sites. The Ca(2+) sites are similar as observed in the HbLt crystal structure. Otherwise, the Zn(2+) sites have no relation with those observed in Cu/Zn SODs. Our peroxidase assays with guaiacol confirm the POD activity and the effect of the zinc ions for HbGp. Our present results on HbGp metal content and their stability effects is the first step to understand the role of these cations in HbGp function in the future. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Metal uptake by homegrown vegetables – The relative importance in human health risk assessments at contaminated sites

    International Nuclear Information System (INIS)

    Augustsson, Anna L.M.; Uddh-Söderberg, Terese E.; Hogmalm, K. Johan; Filipsson, Monika E.M.

    2015-01-01

    Risk assessments of contaminated land often involve the use of generic bioconcentration factors (BCFs), which express contaminant concentrations in edible plant parts as a function of the concentration in soil, in order to assess the risks associated with consumption of homegrown vegetables. This study aimed to quantify variability in BCFs and evaluate the implications of this variability for human exposure assessments, focusing on cadmium (Cd) and lead (Pb) in lettuce and potatoes sampled around 22 contaminated glassworks sites. In addition, risks associated with measured Cd and Pb concentrations in soil and vegetable samples were characterized and a probabilistic exposure assessment was conducted to estimate the likelihood of local residents exceeding tolerable daily intakes. The results show that concentrations in vegetables were only moderately elevated despite high concentrations in soil, and most samples complied with applicable foodstuff legislation. Still, the daily intake of Cd (but not Pb) was assessed to exceed toxicological thresholds for about a fifth of the study population. Bioconcentration factors were found to vary more than indicated by previous studies, but decreasing BCFs with increasing metal concentrations in the soil can explain why the calculated exposure is only moderately affected by the choice of BCF value when generic soil guideline values are exceeded and the risk may be unacceptable. - Highlights: • Uptake of Cd and Pb by lettuce and potatoes increased with soil contamination. • Consumption of homegrown vegetables may lead to a daily Cd intake above TDIs. • The variability in the calculated BCFs is high when compared to previous studies. • Exposure assessments are most sensitive to the choice of BCFs at low contamination

  17. Ecological Catastrophes in the steppe? Landscape Archaeology at the mining and metallurgical complex of Kargaly (Region of Orenbourg, Russia

    Directory of Open Access Journals (Sweden)

    Vicent García, Juan M.

    2000-06-01

    Full Text Available Kargaly is one of the most important centers of mining and metallurgy in the great Eurasian steppe. Dr. E.N. Chernykh and his team (Institute of Archaeology, Russian Academy of Sciences, Moscow and various researchers at the CSIC and other Spanish institutions have developed a joint project to undertake a comprehensive study of the site's two main phases of occupation, the Bronze Age (2nd millenium BC and the first Russian industrialization (1745-1900 AD. The Russian members of the joint team are in charge of the archaeological investigations, while the Spanish members are studying metallurgical and mining technology and production, on the one hand, and the environmental context and impact of these activities, on the other. This article presents the research design and first results of the Palaeoenvironmental research at Kargaly. This work has two aspects. The first consisted of obtaining one of the most complete palaeoenvironmental data sets from the steppes through both the systematic sampling of archaeological sites to recover charcoal, seeds, fruits and pollen and the taking of palynological cores from natural deposits, on the other Both sampling programs were supported by radiocarbon dates. The second aspect, to which the greater part of this article is devoted, was dedicated to contextualizing the palaeobotanical evidence by studying the present-day landscape, with particular attention to understanding the processes which shape the variability of the pollen rain. Our purpose was to obtain explicit and measurable calibrative criteria which would enable us to answer the palaeoenvironmental questions raised by our archaeological and archaeometallurgical research. These questions include, most importantly, the following: what was the extent of forest (the energy base for the mining/metallurgical complex during the Bronze Age? and how do we evaluate subsistence practices? (an issue related to the origins of agriculture on the

  18. A metallurgical and mechanical study on dissimilar Friction Stir welding of aluminum 1050 to brass (CuZn30)

    International Nuclear Information System (INIS)

    Esmaeili, A.; Givi, M.K. Besharati; Rajani, H.R. Zareie

    2011-01-01

    Highlights: → Brass and aluminum 1050 are joined for the first time through Friction Stir welding. → Welding parameters are optimized to obtain a sound joint. → The ultimate tensile strength of the sound joint reaches 80% of aluminum base metal. → The effect of interfacial intermetallic compounds on mechanical properties is probed. → CuZn, Cu9Al4 and CuAl2 form the majority of observed intermetallic compounds. - Abstract: In this research, the effect of Friction Stir welding parameters on mechanical and metallurgical properties of aluminum 1050/brass (70%Cu-30%Zn) joints was investigated. Optical microscopy, SEM, X-ray diffraction analysis and EDS analysis were used to probe microstructures and chemical compositions. In order to examine mechanical properties, besides hardness test, tensile strength of the welds was measured. The main parameters in this study were the tool rotational speed, offset, welding speed, and depth of the sinking pin. The maximum ultimate tensile strength of the joint reached in this research was 80% of the base metal (aluminum). Results show that the optimum parameters will yield a defect free joint arisen from a suitable material flow and a narrow multilayer intermetallic compound at interface in addition to a composite structure in the stir zone which all result in a strong joint. Also, by leaving the optimized condition, occurrence of large brass fragments and weld defects lower weld strength besides shifting fracture path from interface to the stir zone. Also, according to the results, using low rotation speed is accompanied by disappearance of interfacial intermetallic layer, whereas fast rotation will thicken this layer. Moreover, severe mechanical twining is observed in TMAZ of brass which leads to high values of hardness in this region.

  19. Trial-by-fire transformation: an interview with Globe Metallurgical's Arden C. Sims. Interview by Bruce Rayner.

    Science.gov (United States)

    Sims, A C

    1992-01-01

    Globe Metallurgical Inc., a $115 million supplier of specialty metals, is best known as the first small company to win the Baldrige Award in 1988. But there is much more to this gutsy little company than total quality. During the 1980s, Globe transformed itself from a rust-belt has-been on the verge of bankruptcy into a high-technology, high-quality industry leader. Along the way, the company went private in a management-led leveraged buyout, embraced flexible work teams, adopted a high-value-added, niche marketing strategy, and took its business global. Leading the way in Globe's reinvention was Chief Executive Arden C. Sims, the slow-talking son of a West Virginian coal miner. When he joined the company in 1984, Sims had no experience in the new managerial techniques. He was a product of the old school of management: cut costs and trim operations to regain competitiveness. But he soon discovered that old-style management was not enough to battle offshore competitors, an unproductive work force, rising costs, and outdated production technology. He was forced to go looking for new ideas and practices. In a succession of learning experiences, Sims attended a seminar on total quality in 1985, paving the way for the company's quality program; he discovered the power of flexible work teams when management was forced to run the furnaces during a year-long strike; he organized an LBO, allowing him to change the work order even more dramatically; and he took the company global and into highly profitable niche markets by severing a long-standing relationship with Globe's sales and marketing representative. As a result of these and other changes, Globe leads the specialty metals industry in virtually all performance measures.

  20. Environmental characteristics and utilization potential of metallurgical slag: Chapter 19

    Science.gov (United States)

    Piatak, Nadine; De Vivo, Benedetto; Belkin, Harvey E.; Lima, Annamaria

    2018-01-01

    Slag, an abundant byproduct from the pyrometallurgical processing of ores, can be an environmental liability or a valuable resource. The most common environmental impact of slag is from the leaching of potentially toxic elements, acidity, or alkalinity that may impact nearby soils and surface water and groundwater. Factors that influence its environmental behavior include physical characteristics, such as grain size and porosity, chemical composition with some slag being enriched in certain elements, the mineralogy and partitioning of elements in more or less reactive phases, water-slag interactions, and site conditions. Many of these same factors also influence its resource potential. For example, crystalline ferrous slag is most commonly used as construction aggregate, whereas glassy (i.e., granulated) slag is used in cement. Also, the calcium minerals found in ferrous slag result in useful applications in water treatment. In contrast, the high trace-element content of some base-metal slags makes the slags economically attractive for extraction of residual elements. An evaluation tool is used to help categorize a particular slag as an environmental hazard or valuable byproduct. Results for one type of slag, legacy steelmaking slag from the Chicago area in the USA, suggest the material has potential to be used for treating phosphate-rich or acidic waters; however, the pH and trace-element content of resulting solutions may warrant further examination.

  1. Revisiting (Some of) the Lasting Impacts of the Liberty Ships via a Metallurgical Analysis of Rivets from the SS "John W. Brown"

    Science.gov (United States)

    Harris, M. D.; Grogg, W. J.; Akoma, A.; Hayes, B. J.; Reidy, R. F.; Imhoff, E. F.; Collins, P. C.

    2015-12-01

    During World War II, 2710 Liberty ships were built in the United States across 18 ship yards. The rate of production of these ships was at a scale not previously witnessed, reflecting a strategic marshaling of national assets critical to the war effort. For the metallurgist, metallurgical engineer, or materials scientist, these ships also struck commanding images regarding their catastrophic failures. The study of these failures led to increased understanding of brittle fracture, fracture mechanics, and ductile-to-brittle transition temperatures. The post-mortem studies of Liberty ships highlighted the importance of composition and microstructure in controlling the properties of steel in fracture-critical applications. This study examines a rivet from the SS "John W. Brown", which was assembled in Baltimore, Maryland, and launched in September 1942, The "John W. Brown" was restored between 1988 and 1991. Classical metallurgical analysis of a rivet from the original 1942 vessel is compared with modern rivets used during its restoration. The rivets provide an analogue to the plate material used in these ships. A comparison of these materials is presented along with a discussion of the importance of composition-microstructure-property relationships that concomitantly evolved.

  2. Electric arc spraying for restoration and repair of metallurgical equipment parts

    Directory of Open Access Journals (Sweden)

    В’ячеслав Олександрович Роянов

    2016-07-01

    Full Text Available It has been shown that the electric arc spraying with the use of powder wires can be used to repair and restore parts of metallurgical equipment. The technology of spraying parts by means of the cored wire Steelcored M8TUV; T462MMIN5 and combinations of steel and aluminum wires to restore shaft-gears, shaft-beams, cranes axles for the foundry of the Moldavian Metallurgical Plant has been introduced. The composition of the flux-cored wires MMP-2,3 developed at the Department of Equipment and welding production technology of PSTU that provides the required hardness and adhesion of the coating and the substrate have been shown and the results of the coatings properties studies have been published. Studies have shown matching properties of the coatings to be used for details of the metallurgical equipment working under difficult conditions, including the rolls of rolling mills. Cored wire was used for pilot plating of the rolls surface of the skin-rolling stand at the cold-rolling mill at Illich Steel and Iron Works, Mariupol. Residual coating thickness ranged from 15 to 25 microns. Strip sized 0,9 × 1025 mm has been rolled, the squeezing is equal to 0,8...1,0%.

  3. ScMT2-1-3, a Metallothionein Gene of Sugarcane, Plays an Important Role in the Regulation of Heavy Metal Tolerance/Accumulation

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    Jinlong Guo

    2013-01-01

    Full Text Available Plant metallothioneins (MTs, which are cysteine-rich, low-molecular-weight, and metal-binding proteins, play important roles in detoxification, metal ion homeostasis, and metal transport adjustment. In this study, a novel metallothionein gene, designated as ScMT2-1-3 (GenBank Accession number JQ627644, was identified from sugarcane. ScMT2-1-3 was 700 bp long, including a 240 bp open reading frame (ORF encoding 79 amino acid residues. A His-tagged ScMT2-1-3 protein was successfully expressed in Escherichia coli system which had increased the host cell’s tolerance to Cd2+, Cu2+, PEG, and NaCl. The expression of ScMT2-1-3 was upregulated under Cu2+ stress but downregulated under Cd2+ stress. Real-time qPCR demonstrated that the expression levels of ScMT2-1-3 in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both the E. coli assay and sugarcane plantlets assay suggested that ScMT2-1-3 is significantly involved in the copper detoxification and storage in the cell, but its functional mechanism in cadmium detoxification and storage in sugarcane cells needs more testification though its expressed protein could obviously increase the host E. coli cell’s tolerance to Cd2+. ScMT2-1-3 constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.

  4. Diversity management – a tool to improve a metallurgic enterprise

    Directory of Open Access Journals (Sweden)

    A. Wziątek-Staśko

    2013-01-01

    Full Text Available Global recognition of the Diversity Management concept is growing day by day and he is one of the most popular business areas of the past two decades. This article emphasises the key role played by diversity management in the process of optimising economic and social effectiveness of an enterprise, with a particular emphasis on the importance of the strategy in the operations of ArcelorMittal.

  5. Some metallurgical aspects of ancient silver coins discovered in romania (original and imitations) - provenance, destination and commercial networks

    International Nuclear Information System (INIS)

    Constantinescu, Bogdan; Cojocaru, Viorel; Bugoi, Roxana

    2007-01-01

    migrated to the South and Southeast Dacia. - The preference for adding tin (and maybe also lead) in Ag/Cu alloys is due probably to the fact that tin fades the red color of copper, resulting a silvery nuance. In addition the melting point of alloy is lowered which was important for an unsophisticated metallurgy. Although tin does almost not exist in the earth of old Romania territory, bronze objects (huge medals, statues, coins, etc.) were common enough and easy to be found. - Lead concentration also increased in time bringing out to a quaternary alloy (Ag+Cu+Sn+Pb), such as in Varteju-Carlomanesti and/or Radulesti-Hunedoara issues. Such an alloy also generalized in the Roman coinage, but much latter (c. AD 250). 23 - Although hundreds of Geto-Dacian coins were investigated by atomic and nuclear techniques, no entirely bronze or copper coin was found except a few proved modern fakes. In the same time official fake coins made of bronze was a practice in extra Dacian territory. This can be understood by the metallurgical methods used by Geto-Dacians. If the coin alloy had no Au or Ag, the melting into a clay cylinder would wet the clay preventing the formation of a globule necessary for the coin blank. Even for an alloy with a smaller concentration of noble metals, the adding of some charcoal and clay dust will produce a carbon monoxide atmosphere around of metal that prevents the oxides formation and will help the globule appearance. As concerning the Apollonia - Dyrrhachium drachms, five main categories were found: - original coins (similar to drachms emitted before the Civil War) with 97-99% silver, low (1-2%) copper content, - debased coins with silver content down to 70% and copper content from 5 to 25%, probably emitted due to inflation problem, normal phenomenon for an economy in war, - official (original dies) counterfeits from bronze (70% copper and 30% tin) covered by a very thin layer of argentarium (tin-lead alloy imitating the silver), - official counterfeits

  6. THE ROLE OF SHIELDING GAS ON MECHANICAL, METALLURGICAL AND CORROSION PROPERTIES OF CORTEN STEEL WELDED JOINTS OF RAILWAY COACHES USING GMAW

    Directory of Open Access Journals (Sweden)

    Byju John

    2016-12-01

    Full Text Available This analysis lays emphasis on finding a suitable combination of shielding gas for welding underframe members such as sole bar of Railway Coaches made of corten steel; for improved mechanical, metallurgical and corrosion properties of welds using copper coated solid MIG/MAG welding filler wire size 1.2 mm conforming to AWS/SFA 5.18 ER 70 S in Semi-automatic GMAW process. Solid filler wire is preferred by welders due to less fumes, practically no slag and easy manipulation of welding torch with smooth wire flow during corrosion repair attention, when compared to Flux cored wire. Three joints using Gas metal arc welding (GMAW with shielding gases viz., Pure CO2, (80% Ar – 20% CO2 and (90% Ar – 10% CO2 were made from test pieces cut from Sole bar material of Railway Coach. Study of Mechanical properties such as tensile strength, hardness and toughness revealed that welded joint made using shielding gas (80% Ar – 20% CO2 has better Mechanical properties compared to the other two shielding gases and comparable to that of Parent metal. Type of Shielding gas used has influence on the chemical composition and macro & micro structures. The Tafel extrapolation study of freshly ground samples in 3.5% NaCl solution revealed that the welded joint made using shielding gas (80% Ar – 20% CO2 has also better corrosion resistance which is comparable to the Parent metal as well as similar commercial steels.

  7. Metal Recovery from Industrial Solid Waste — Contribution to Resource Sustainability

    Science.gov (United States)

    Yang, Yongxiang

    Increased demand of metals has driven the accelerated mining and metallurgical production in recent years, causing fast depletion of primary metals resources. On the contrary, the mining and metallurgical industry generates large amount of solid residues and waste such as tailings, slags, flue dust and leach residues, with relative low valuable metal contents. On the other hand, end-of-life (EoL) consumer products form another significant resources. The current technology and processes for primary metals production are not readily applicable for direct metals extraction from these waste materials, and special adaptation and tailor-made processes are required. In the present paper, various solid waste resources are reviewed, and current technologies and R&D trends are discussed. The recent research at author's group is illustrated for providing potential solutions to future resource problems, including metal recovery from MSW incinerator bottom ashes, zinc recovery from industrial ashes and residues, and rare earth metals recovery from EoL permanent magnets.

  8. Resistance Upset Welding of ODS Steel Fuel Claddings—Evaluation of a Process Parameter Range Based on Metallurgical Observations

    Directory of Open Access Journals (Sweden)

    Fabien Corpace

    2017-08-01

    Full Text Available Resistance upset welding is successfully applied to Oxide Dispersion Strengthened (ODS steel fuel cladding. Due to the strong correlation between the mechanical properties and the microstructure of the ODS steel, this study focuses on the consequences of the welding process on the metallurgical state of the PM2000 ODS steel. A range of process parameters is identified to achieve operative welding. Characterizations of the microstructure are correlated to measurements recorded during the welding process. The thinness of the clad is responsible for a thermal unbalance, leading to a higher temperature reached. Its deformation is important and may lead to a lack of joining between the faying surfaces located on the outer part of the join which can be avoided by increasing the dissipated energy or by limiting the clad stick-out. The deformation and the temperature reached trigger a recrystallization phenomenon in the welded area, usually combined with a modification of the yttrium dispersion, i.e., oxide dispersion, which can damage the long-life resistance of the fuel cladding. The process parameters are optimized to limit the deformation of the clad, preventing the compactness defect and the modification of the nanoscale oxide dispersion.

  9. Heavy metals (lead, cadmium, methylmercury, arsenic) in commonly imported rice grains (Oryza sativa) sold in Saudi Arabia and their potential health risk.

    Science.gov (United States)

    Al-Saleh, Iman; Abduljabbar, Mai

    2017-10-01

    The levels of heavy metals (lead, cadmium, methylmercury and arsenic) were determined in 37 brands of imported rice commonly consumed in Saudi Arabia after soaking and rinsing with water, and their potential health risks to residents were estimated by three indices: hazard quotient (HQ), hazard index (HI) and cancer risk (CR). The mean levels of lead, cadmium, methylmercury and total arsenic in soaked (rinsed) rice grains were 0.034 (0.057), 0.015 (0.027), 0.004 (0.007) and 0.202 (0.183) μg/g dry weight, respectively. Soaking or rinsing rice grains with water decreased lead and cadmium levels in all brands to safe levels. All brands had total arsenic above the acceptable regulatory limits, irrespective of soaking or rinsing, and eight soaked and 12 rinsed brands contained methylmercury. The levels of all heavy metals except cadmium were above the acceptable regulatory limits when the rice was neither rinsed nor soaked. Weekly intakes of lead, cadmium, methylmercury and total arsenic from soaked (rinsed) grains were 0.638 (1.068), 0.279 (0.503), 0.271 (0.309) and 3.769 (3.407) μg/kg body weight (bw). The weekly intakes of lead and methylmercury from the consumption of one rinsed and two soaked rice brands respectively, exceeded the Provisional Tolerance Weekly Intake set by the Food and Agriculture Organization and the World Health Organization. The weekly intake of total arsenic for all brands was above the lowest benchmark dose lower confidence limit (BMDL 01 ) level of 0.3μg/kg bw/d for an increased cancer risk set by European Food Safety Authority. Either soaking or rinsing grains before consumption can minimize the non-carcinogenic health risks to residents from cadmium and lead (HQrice contaminated mainly with arsenic (HQ>1 all brands) and to a lesser extent with methylmercury (HQ>1 in 4 brands), even when soaked or rinsed with water before consumption. The combined non-carcinogenic effect of all metals expressed as HI was >1, including soaked or rinsed

  10. Influence of carbon nano tubes on mechanical, metallurgical and tribological behavior of magnesium nanocomposites

    Directory of Open Access Journals (Sweden)

    S.T. Selvamani

    2017-09-01

    Full Text Available In this research work, three different reinforcements of Carbon Nano Tubes (in weight % such as 2%, 3% and 4% were added to the magnesium AZ91D grade magnesium alloy to fabricate the Nanocomposites through stir casting method. The effects of volume percentage on the mechanical, metallurgical and wear behavior were analyzed. The composites with 4% reinforcement show high hardness while the composites with 3% reinforcement show better tensile and yield strength and also an improved wear resistance compared to other. Also, the characterization of the Nanocomposites were made using Optical Microscopy, Scanning Electron Microscopy, Finite Element – Scanning Electron Microscopy and Transmission Electron Microscopy to understand its nature.

  11. Metallurgical and acoustical characterization of a hydroformed, 304 stainless steel, Caribbean-style musical pan

    International Nuclear Information System (INIS)

    Murr, L.E.; Gaytan, S.M.; Lopez, M.I.; Bujanda, D.E.; Martinez, E.Y.; Whitmyre, G.; Price, H.

    2008-01-01

    We report herein the metallurgical and acoustical characterization of hydroformed 304 stainless steel, Caribbean pans. These pans were fully tuned to chromatic tones and compared to a manufactured, low-carbon, Caribbean steel pan standard. Hydroformed platforms had a Vickers microindentation hardness of HV 345, which was reduced by annealing during pan fabrication to HV 270. Skirts welded to the hydroformed head had a microindentation hardness of HV 440. Microstructural characterization by light optical metallography and transmission electron microscopy illustrated microstructures (including grain structures) characteristic of these pan microindentation hardnesses

  12. Effective recruitment method for the marketing department of a metallurgical enterprise

    Directory of Open Access Journals (Sweden)

    E. Jaba

    2014-04-01

    Full Text Available This paper presents some solutions to recruit staff for the Marketing Department of a metallurgical enterprise. Our goal is to present the psychological characteristics of a certain category of employees on a sample of 107 employees and to evaluate the relationship between the motivation to work and those characteristics. In order to realize such evaluation we used the linear mixed effects model in the statistical software program R. The results showed that a significant effect on work motivation have factors like work climate and the employee agreeability.

  13. SOCIO-ECONOMICAL SUBSTANTIATION OF LARGE INTEGRATED STRUCTURES IN METALLURGICAL COMPLEX CREATION

    Directory of Open Access Journals (Sweden)

    A.A. Kozitsyn

    2007-03-01

    Full Text Available The main tendencies of Russia and Urals economy development on modern stage are considered; the necessity of creation of large integrated structures is shown. The methodical apparate of effectiveness evaluation of manufactural-territorial integration in regional economy is given, in its base the use of complex evaluation of economical safety of the territory is put. On the example of Urals mining-metallurgical company the effectiveness evaluation of creation and functioning of large integrated structure for municipal formations of Sverdlovskaya area in retrospective (2000 − 2004 yy and perspective (for the period till 2010 y periods is conducted.

  14. [Three years of work-related accidents in a metallurgic plant: ways to its understanding].

    Science.gov (United States)

    Gonçalves, Cláudia Giglio de Oliveira; Dias, Adriano

    2011-02-01

    The objective of this study is to describe, by quantitative and qualitative methods, industrial accidents occurred during three years in a metallurgic plant in the rural area to understand the possible causes. It is a case study in a metallurgic plant where 336 accidents were studied in a 3-year period by means of three procedures: analysis of accidents' registers, interviews with 166 hurt workers, and the organization of Focal Groups (111 workers) for discussion. The ratio of yearly incidence of accidents was 16.9%; 75 cases required more than 15 out-of-work days; 51.2% occurred in the morning and affected boilermakers (48.2%). Among the interviewed workers, average schooling was 8.8 years, age ranged from 31-50 years (55.4%), 64.5% of workers had already suffered more than one accident. Besides, workers exposed to intense noise (+ 90 dBA) were the most affected (53%). In the focal groups, perceptions and feelings of workers regarding the accidents were identified that had not appeared in the previous stages. It can be concluded that focal groups allow for a better identification of factors that may contribute for accidents such as performance pressures, extra-hours of work, low wages, and precarious conditions of work and work organization.

  15. Metallurgical study of stress corrosion in aqueous media of alloy 600 (NC15Fe)

    International Nuclear Information System (INIS)

    Garriga-Majo, Denis

    1993-01-01

    The development of intergranular cracks have been noticed in steam generator tubes made of alloy 600. These cracks result in tube embrittlement, and several actions have been implemented to try to improve tube strength, mainly by reducing the applied mechanical solicitations. For given temperature, chemistry and mechanical solicitations, the alloy sensitivity seems to depend on its micro-structural condition. Thus, after a general description of stress corrosion cracking phenomena, the main existing theories are reviewed as well as means to reproduce these cracking phenomena in laboratory. The author addresses general and microstructure properties of Alloy 600, metallurgical, electrochemical or mechanical parameters which govern its stress corrosion cracking behaviour, and different theories proposed to model and predict this behaviour. In the second part, the author studies the structure of Alloy 600 tubes before their installation in the steam generator: metallurgical study, search for parameters enabling the prediction of tube microstructure and tensile characteristics, study of the origin of microstructure differences with respect to tube fabrication batch. The third part addresses the study of Alloy 600 plasticity and creep with respect to its micro-structural condition, with a particular attention to material deformation mechanisms at grain boundaries. The fourth part reports the analysis of the stress corrosion behaviour of steam generator tubes in pure water and in primary environment [fr

  16. Characterization of Tool Wear in High-Speed Milling of Hardened Powder Metallurgical Steels

    Directory of Open Access Journals (Sweden)

    Fritz Klocke

    2011-01-01

    Full Text Available In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC. The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill (0 = 6, TiAlN coating. It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.

  17. Relation between the optical and metallurgical properties of polished molybdenum mirrors

    Science.gov (United States)

    Bennett, J. M.; Wong, S. M.; Krauss, G.

    1980-10-01

    A study has been performed to determine the correlation among the microstructure, metallurgical processing, and optical surface finish of commercially available types of molybdenum (Mo) bar and plate and 0.5-mm thick Mo sheet. Specimens of bar and plate stock produced from low-carbon vacuum-arc Mo or powder-metallurgy-processed Mo, as well as TZM(Ti-Zr-Mo) Mo alloy, were in the form of 3.86-cm diam disks. In addition, typical cross-rolled sheet specimens were produced from powder-metallurgy-processed Mo that had a very fine grain structure and a high degree of texture. Specimens were extensively characterized both optically and metallurgically. It was found that well-polished surfaces have surface topographies directly related to the microstructure and hence to the processing of the material. In sheet material having a well-developed texture, the polishability appeared to be independent of texture, and the grain size did not result in a lower scatter surface. It was concluded that the optimum type of Mo to use for smooth low-scatter mirrors is low-carbon vacuum-arc-cast plate or sheet material.

  18. A thermo-metallurgical constitutive law of steels for structural mechanics

    International Nuclear Information System (INIS)

    Waeckel, Francois

    1994-01-01

    The aim of this work is to include the metallurgical behaviour of steels (and specifically their phases transformations) into thermo-mechanical studies. For this, a new model of aniso-thermal phase transformations during the cooling stage is proposed. Developed in the thermodynamics framework of simple materials with memory variables, its originality lies in the choice of the temperature time derivative T as independent variable. The identification and the transformation rates computation use the C.C.T. diagrams which are considered as families of particular solutions of evolution equations. The validation shows ability of the model to simulate all C.C.T. deductible tests. Furthermore, for some tests not included into the C.C.T., the numerical results remain good and the model, from which evolution equation form has been let free, allows to incorporate them to the identification data without modifying the C.C.T. simulation accuracy. Lastly, to take into account structural transformations mechanical effects, some currently used models have been introduced, together with the metallurgical model, in a finite element code. They allow whole quenching or welding simulations (up to residual stresses) as demonstrated by application examples. (author) [fr

  19. Occupational exposure in South African metallurgical plants and industries involving naturally occurring radionuclides

    International Nuclear Information System (INIS)

    Kruger, I.D.

    2002-01-01

    South Africa has a very large mining and minerals processing industry exploiting a variety of ores and minerals containing elevated levels of NORM. The industry employs more than 300,000 persons. Doses have been assessed to workers in the mining industry in South Africa. In the gold mining industry radon measurements have been performed since the early 1970s. Regulations have been in force since 1990. The mean annual dose to underground gold mine workers, mostly from radon progeny, is about 5 mSv with maximum doses exceeding 20 mSv. The maximum annual dose to surface workers in gold mines is 5 mSv. In South African coal mines the mean annual dose from inhalation of radon decay products has been estimated from limited radon concentration measurements to be about 0.6 mSv. In the phosphoric acid and fertilizer production industry the doses to the workers do not exceed 6 mSv/y. There are 3 mineral sands operations in South Africa, for which the maximum annual dose to workers is 3 mSv. One open pit copper mine contains elevated levels of U, which is extracted as a by-product. The maximum annual doses to workers are 5 mSv for workers in the mine and 20 mSv for workers in the metallurgical plant. Worker doses in the metallurgical plant have since been reduced with the introduction of radiation protection measures

  20. Metallurgical characterization of pulsed current gas tungsten arc, friction stir and laser beam welded AZ31B magnesium alloy joints

    International Nuclear Information System (INIS)

    Padmanaban, G.; Balasubramanian, V.

    2011-01-01

    This paper reports the influences of welding processes such as friction stir welding (FSW), laser beam welding (LBW) and pulsed current gas tungsten arc welding (PCGTAW) on mechanical and metallurgical properties of AZ31B magnesium alloy. Optical microscopy, scanning electron microscopy, transmission electron microscopy and X-Ray diffraction technique were used to evaluate the metallurgical characteristics of welded joints. LBW joints exhibited superior tensile properties compared to FSW and PCGTAW joints due to the formation of finer grains in weld region, higher fusion zone hardness, the absence of heat affected zone, presence of uniformly distributed finer precipitates in weld region.

  1. Possibilities of Formation of Dioxins and Furans in Metallurgical Processes as well as Methods of their Reduction

    Directory of Open Access Journals (Sweden)

    Holtzer, M.

    2007-01-01

    Full Text Available The metallurgical industry, among others, generates various kinds of wastes: gaseous, dusts, wastes and sewage. Special attention of the European Union is directed towards the elimination or significant reduction of the gaseous-dust contamination emissions including the most hazardous compounds, such as dioxins and furans. In the article the sources of dioxins and furans in metallurgical industry are described along with the reduction methods of these pollutants. Particularly the activities recommended as the Best Available Techniques (BAT in order to reduce the PCDD/PCDF emission from sintering processes, non-ferrous metallurgy and foundry engineering have been presented.

  2. Project development for mining-metallurgical complexes for production of uranium concentrates - an analysis and a methodology

    International Nuclear Information System (INIS)

    Ajuria G, S.; Blanco P, B.; Pena A, J.; Manzanera Q, C.

    1978-10-01

    Activities comprising the development of a project for a mining-metallurgical complex for production of uranium concentrates, from sampling and evaluation of an orebody until plant start-up, are analyzed. The analysis of the orebody, characterization of the ore, bench scale and pilot plant metallurgical studies, environmental studies and economic analyses of the project are described. The mining project and mine preparation and engineering and construction of the plant are reviewed in less detail. The estimated time lapse for the development of a typical project under ideal conditions is 66 months. A bar diagram is included showing an approximate timetable for each activity. (author)

  3. Measures to restore metallurgical mine wasteland using ecological restoration technologies: A case study at Longnan Rare Earth Mine

    Science.gov (United States)

    Rao, Yunzhang; Gu, Ruizhi; Guo, Ruikai; Zhang, Xueyan

    2017-01-01

    Whereas mining activities produce the raw materials that are crucial to economic growth, such activities leave extensive scarring on the land, contributing to the waste of valuable land resources and upsetting the ecological environment. The aim of this study is therefore to investigate various ecological technologies to restore metallurgical mine wastelands. These technologies include measures such as soil amelioration, vegetation restoration, different vegetation planting patterns, and engineering technologies. The Longnan Rare Earth Mine in the Jiangxi Province of China is used as the case study. The ecological restoration process provides a favourable reference for the restoration of a metallurgical mine wasteland.

  4. Importance of doping, dopant distribution, and defects on electronic band structure alteration of metal oxide nanoparticles: Implications for reactive oxygen species

    International Nuclear Information System (INIS)

    Saleh, Navid B.; Milliron, Delia J.; Aich, Nirupam; Katz, Lynn E.; Liljestrand, Howard M.; Kirisits, Mary Jo

    2016-01-01

    Metal oxide nanoparticles (MONPs) are considered to have the potency to generate reactive oxygen species (ROS), one of the key mechanisms underlying nanotoxicity. However, the nanotoxicology literature demonstrates a lack of consensus on the dominant toxicity mechanism(s) for a particular MONP. Moreover, recent literature has studied the correlation between band structure of pristine MONPs to their ability to introduce ROS and thus has downplayed the ROS-mediated toxicological relevance of a number of such materials. On the other hand, material science can control the band structure of these materials to engineer their electronic and optical properties and thereby is constantly modulating the pristine electronic structure. Since band structure is the fundamental material property that controls ROS-producing ability, band tuning via introduction of dopants and defects needs careful consideration in toxicity assessments. This commentary critically evaluates the existing material science and nanotoxicity literature and identifies the gap in our understanding of the role of important crystal structure features (i.e., dopants and defects) on MONPs' electronic structure alteration as well as their ROS-generation capability. Furthermore, this commentary provides suggestions on characterization techniques to evaluate dopants and defects on the crystal structure and identifies research needs for advanced theoretical predictions of their electronic band structures and ROS-generation abilities. Correlation of electronic band structure and ROS will not only aid in better mechanistic assessment of nanotoxicity but will be impactful in designing and developing ROS-based applications ranging from water disinfection to next-generation antibiotics and even cancer therapeutics. - Highlights: • Metal oxide nanoparticles (MONPs) produce reactive oxygen species (ROS) • Band structure of pristine MONPs is different than those with dopants/defects • Dopants/defects modulate

  5. Importance of doping, dopant distribution, and defects on electronic band structure alteration of metal oxide nanoparticles: Implications for reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, Navid B., E-mail: navid.saleh@utexas.edu [Department of Civil, Architectural, and Environmental Engineering, University of Texas, Austin, TX 78712 (United States); Milliron, Delia J. [McKetta Department of Chemical Engineering, University of Texas, Austin, TX 78712 (United States); Aich, Nirupam [Department of Civil, Structural and Environmental Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260 (United States); Katz, Lynn E.; Liljestrand, Howard M.; Kirisits, Mary Jo [Department of Civil, Architectural, and Environmental Engineering, University of Texas, Austin, TX 78712 (United States)

    2016-10-15

    Metal oxide nanoparticles (MONPs) are considered to have the potency to generate reactive oxygen species (ROS), one of the key mechanisms underlying nanotoxicity. However, the nanotoxicology literature demonstrates a lack of consensus on the dominant toxicity mechanism(s) for a particular MONP. Moreover, recent literature has studied the correlation between band structure of pristine MONPs to their ability to introduce ROS and thus has downplayed the ROS-mediated toxicological relevance of a number of such materials. On the other hand, material science can control the band structure of these materials to engineer their electronic and optical properties and thereby is constantly modulating the pristine electronic structure. Since band structure is the fundamental material property that controls ROS-producing ability, band tuning via introduction of dopants and defects needs careful consideration in toxicity assessments. This commentary critically evaluates the existing material science and nanotoxicity literature and identifies the gap in our understanding of the role of important crystal structure features (i.e., dopants and defects) on MONPs' electronic structure alteration as well as their ROS-generation capability. Furthermore, this commentary provides suggestions on characterization techniques to evaluate dopants and defects on the crystal structure and identifies research needs for advanced theoretical predictions of their electronic band structures and ROS-generation abilities. Correlation of electronic band structure and ROS will not only aid in better mechanistic assessment of nanotoxicity but will be impactful in designing and developing ROS-based applications ranging from water disinfection to next-generation antibiotics and even cancer therapeutics. - Highlights: • Metal oxide nanoparticles (MONPs) produce reactive oxygen species (ROS) • Band structure of pristine MONPs is different than those with dopants/defects • Dopants/defects modulate

  6. Correlation Between the Efficiency of Machinery and Equipment and the Productivity of Workers and its Effect on the Performance of a Metallurgical Undertaking

    Directory of Open Access Journals (Sweden)

    Kulawik, A.

    2007-01-01

    Full Text Available In this paper the example of procedure of life and objectify work effectiveness analysis in metallurgical enterprise were presented. Besides, on the example of chosen units of metallurgical enterprise, results of analysis - based on methodic proposed in the article - were discussed.

  7. Metallurgical and mechanical behaviours of PWR fuel cladding tube oxidised at high temperature; Comportements metallurqigue et mecanique des materiaux de gainage du combustible REP oxydes a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Stern, A

    2007-12-15

    Zirconium alloys are used as cladding materials in Pressurized Water Reactors (PWR). As they are submitted to very extreme conditions, it is necessary to check their behaviour and especially to make sure they meet the safety criteria. They are therefore studied under typical in service-loadings but also under accidental loadings. In one of these accidental scenarios, called Loss of Coolant Accident (LOCA) the cladding temperature may increase above 800 C, in a steam environment, and decrease before a final quench of the cladding. During this temperature transient, the cladding is heavily oxidised, and the metallurgical changes lead to a decrease of the post quench mechanical properties. It is then necessary to correlate this drop in residual ductility to the metallurgical evolutions. This is the problem we want to address in this study: the oxidation of PWR cladding materials at high temperature in a steam environment and its consequences on post quench mechanical properties. As oxygen goes massively into the metallic part - a zirconia layer grows at the same time - during the high temperature oxidation, the claddings tubes microstructure shows three different phases that are the outer oxide layer (zirconia) and the inner metallic phases ({alpha}(O) and 'ex {beta}') - with various mechanical properties. In order to reproduce the behaviour of this multilayered material, the first part of this study consisted in creating samples with different - but homogeneous in thickness - oxygen contents, similar to those observed in the different phases of the real cladding. The study was especially focused on the {beta}-->{alpha} phase transformation upon cooling and on the resulting microstructures. A mechanism was proposed to describe this phase transformation. For instance, we conclude that for our oxygen enriched samples, the phase transformation kinetics upon cooling are ruled by the oxygen partitioning between the two allotropic phases. Then, these materials

  8. Optimization Review: Bunker Hill Mining and Metallurgical Complex Superfund Site, Central Treatment Plant (CTP), Kellogg, Shoshone County, Idaho

    Science.gov (United States)

    The Bunker Hill Mining and Metallurgical Complex Superfund Site includes all areas of the Coeur d’Alene Basin where mining-related contamination occurred and encompasses a 21-square mile “Box” along Interstate 90 surrounding the former smelter complex.

  9. Metallurgical source-contribution analysis of PM10 annual average concentration: A dispersion modeling approach in moravian-silesian region

    Directory of Open Access Journals (Sweden)

    P. Jančík

    2013-10-01

    Full Text Available The goal of the article is to present analysis of metallurgical industry contribution to annual average PM10 concentrations in Moravian-Silesian based on means of the air pollution modelling in accord with the Czech reference methodology SYMOS´97.

  10. Risk Assessment of Heavy Metals in Imported Frozen Fish Scomber scombrus Species Sold in Nigeria: A Case Study in Zaria Metropolis

    Directory of Open Access Journals (Sweden)

    Abdullahi Abubakar

    2015-01-01

    Full Text Available This study assesses the likely health risks to human contamination of heavy metals from fish consumption. The analysis of the idea of fish destination and status (fishing area for heavy metals was determined by the assessment of its risk limits (daily intake of metal and health risk index. Variations in the accumulation of heavy metals concentrations were between various tissues/organs (skin, muscle, gills, liver, intestine, kidneys, brain, and bones across the batches of two fishing origins. Post hoc (Duncan multicomparison shows that there are significant differences (PHg>Pb>Cd>Ni and were above the recommended safety limits outlined by FAO/WHO. However, the consumer’s health risk with the consumption of fish muscles tissues shows that there are greater tendencies for cadmium, lead, and mercury exposure. Also consumption of Scomber scombrus species above the recommended daily intake (stated in this study might lead to ingestion of heavy metals at unacceptable concentrations.

  11. Mechanical fasteners used in historical Siberian shipbuilding: perspectives for metallurgical analysis

    Science.gov (United States)

    Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

    2017-10-01

    Recent discoveries of shipwrecked vessels in the northern reaches of the river Yenisei led to a number of questions concerning the history of shipbuilding in Siberia and the technical features of the first vessels of the industrial era to navigate the Northern Sea Route and the Yenisei. One of these questions addresses the features of mechanical fasteners used in the construction of the Siberian vessels. The answer to this question may provide information on how the first vessels, constructed in Siberia during the 1870’s, were able to sail the high seas of the Arctic Ocean and reach European ports. In this paper, we provide a description of iron mechanical fasteners obtained from one shipwrecked vessel and discuss on the perspectives of a metallurgical analysis This research has been funded by a grant of the Russian Fund of Humanities Research (Russian Fund of Fundamental Research) and the Krasnoyarsk Regional Science Fund under Grant number 16-11-24010.

  12. Arsenic precipitation from metallurgical effluents; Precipitacion de arsenico desde efluentes metalurgicos

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, P.; Vargas, C.; Araya, E.; Martin, I.; Alguacil, F. J.

    2004-07-01

    In the mining-metallurgical companies different liquid effluents are produced, which can contain a series of dissolved elements that are considered dangerous from an environmental point of view. One of these elements is the arsenic, especially in the state of oxidation +5 that can be precipitated as calcium or iron arsenate. To fulfil the environmental requests it should have in solution a content of arsenic lower than 0,5 mg/l and the obtained solid product should be very stable under the condition in which it will be stored. this work looks for the best conditions of arsenic precipitation, until achieving contents in solution lower than such mentioned concentration. Also, the stability of the precipitates was studied. (Author) 7 refs.

  13. Utilizing of the metallurgical slag for production of cementless concrete mixtures

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2012-10-01

    Full Text Available In process of pig iron, steel and cast iron production besides main product, also secondary products are formed, that have character of secondary raw materials and industrial wastes. The most abundant secondary product originating in the metallurgical process is furnace slag. Total amount of accured slag, also its chemical, mineralogical, physical – chemical properties and similarity with natural stones predestinate its utilisation in different fields of industry. The contribution deals with production of cementless concrete mixtures, where the main parts were formed by blast furnace granulated slag grinded and different gravel slag from blast furnace, oxygen converter and electric arc furnace. As activators of solidification different kinds of water glass were tested.

  14. Determination of Japanese buyer valuation of metallurgical coal characteristics by hedonic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, R.J. [Griffith University, Brisbane, Qld. (Australia). Graduate School of Management

    2001-09-01

    Considerable efforts have been devoted by econometric researchers to understanding Japanese steel mill (JSM) metallurgical coal valuation policies, and whether such policies disadvantage coal exporters. Much of this research has employed the hedonic regression modeling technique of Rosen and examines the significance of coal quality in establishing market price. This article discusses shortcomings in some such modeling studies, and presents results of additional hedonic modeling to buttress findings of previous work suggesting that cross-cultural bargaining factors rather than coal quality explain lower prices for Australian coals in Japanese market settlements. Policy changes that might be effective in ameliorating bilateral market distortions arising from oligopsony characteristics exhibited in JSM contract settlements are then explored. 29 refs., 2 figs., 2 tabs.

  15. Change of the layout of an office of a metallurgical company: simple projects, big solutions.

    Science.gov (United States)

    Duarte, Luiz Carlos da Silva; Eckhardt, Moacir; da Motta, Giordano Paulo

    2012-01-01

    The posture, a good organization and the proper layout of the environment and workplaces have a positive influence on the income of an employee. To develop the work it is used a methodology that addressed the study phases of the theory involving the subject, description of the current situation, preparation of conceptions, choice of design, implementation and reporting of results. Through the project of "Change of the layout of an office of a metallurgical company" there was an intervention in these reported aspects providing improvements in the office, regarding ergonomic, layout, workplace and lighting issues, bringing welfare to the official, with the intent to improve its performance within the company and facilitating its actions, as the company's customer service. The results provided improvements in layout, in the workplace and especially in comfort for the human resources that perform their activities.

  16. DIFFERENCES OF COMMITMENT BETWEEN GENERATIONS X AND Y – A STUDY IN A METALLURGICAL INDUSTRY

    Directory of Open Access Journals (Sweden)

    Fábio Teodoro Tolfo Ribas

    2015-06-01

    Full Text Available The way each generation acts in society and in organizations is always a matter of study and appreciation (LOMBARDIA; STEIN & PIN, 2008. Thus, this study aimed to examine the organizational commitment in its affetctive, instrumental and normative dimensions in different generational groups (X and Y of Metallurgical Industry in the city of Caxias do Sul (RS. The research is descriptive and quantitative in nature. To reach its objective it uses a validated questionnaire, based on Ribas 2010, with 96 professional of the administrative sector. The results identify that the respondents have very similar approaches regarding affective, instrumental and normative commitment perceptions. Still, it was noticed that the highest means for both generations, were obtained in the construct of affective commitment. The clearest difference emerged in the focus of instrumental commitment, which determines the individual’s need to remain in business.

  17. Metallurgical and Chemical Characterization of Bronze Remains Found at the Houhe Site in Shanxi Province, China

    Science.gov (United States)

    Mu, D.; Nan, P. H.; Wang, J. Y.; Song, G. D.; Luo, W. G.

    2015-07-01

    This study attempts to determine the metallurgical and chemical characteristics of Chinese bronze artifacts from the early Iron Age by taking the bronze artifacts from the Houhe site as an example. The bronze artifacts included vessels, buckles, mirrors, and bells. Elemental compositions of 10 Chinese bronze artifacts from the Houhe site were determined by an x-ray fluorescence system. Microstructures were observed by a polarizing microscope. Most of the artifacts were cast and lacked external evidence of secondary processing. The copper content of the vessels is higher than the other samples, and the copper content of buckles is the lowest. High tin content is a distinctive characteristic of the mirrors. Through comparisons, bells show a decline in the content of copper from the Western Zhou dynasty to the early Han dynasty, and the content of lead increased over time. Combined with historical studies, the findings show that there may have been industrial standards for bronze production during the Han dynasty.

  18. GEOLOGY OF THE FLORENCIA GOLD – TELLURIDE DEPOSIT (CAMAGÜEY, CUBA AND SOME METALLURGICAL CONSIDERATIONS

    Directory of Open Access Journals (Sweden)

    López K Jesús M.

    2006-12-01

    Full Text Available This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors.
    It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones.

  19. Atomic absorption determination of vanadium in products of metallurgical production and mineral feed stock

    International Nuclear Information System (INIS)

    Polikarpova, N.V.; Panteleeva, E.Yu.

    1983-01-01

    Rapid and selective method of atomic absorption determination of vanadium in metallurgical process products and numerical feed stock is suggested. Buffering mixture of aluminium and phosphoric acid is used to suppress the effect of sample composition on the value of vanadium atomic absorption. The concentration of buffer components can vary from 400 up to 2000 μg/ml Al and from 2 up to 5% vol. H 3 PO 4 . The suggested mixture completely eli-- minates the strong chromium effect. The developed method was used for analyzing steels, alloys based on Mo, Ni, Ti, Cr, as well as titanium magnetite ores and concentrates. The method enables to determine from 0.05 up to 10% vanadium with 0.05-0.01 relative standard deviation, respectively

  20. Ex situ characterization of metallurgical inclusions in X100 pipeline steel before and after immersion in a neutral pH bicarbonate solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingbo; Liu, Jie [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Deng, Yida [Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Han, Xiaopeng [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Hu, Wenbin [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Zhong, Cheng, E-mail: cheng.zhong@tju.edu.cn [Key Laboratory of Advanced Ceramics and Machining Technology (Ministry of Education), School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2016-07-15

    The initiation of corrosion pits in pipeline steels plays an important role in the development of stress corrosion cracking. In order to reveal the effect of inclusions on corrosion initiation sites and also to clarify contradictory results from previous literature, we proposed an ex situ characterization method that is allowed to characterize exactly the same inclusion or location of the surface of steel before and after corrosion tests. The time-dependent corrosion behaviour of the inclusions and the surrounding X100 steel matrix at the same area before and after early stage immersion in a near-neutral pH bicarbonate solution was investigated by ex situ scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis and localized electrochemical impedance spectroscopy (LEIS). The sizes of most inclusions in X100 steel are below 3 μm. The results challenge the long-held opinion of previous work that corrosion pit initiations are related with the inclusions. It has been found that most of the inclusions remain stable (intact) during the whole testing time although severe corrosion occurs on the matrix of the steel. The chemical composition of the inclusion greatly affects the chemical stability of the inclusion. SiO{sub 2} inclusions and complex inclusions with a high SiO{sub 2} content remain intact although obvious general corrosion occurs on the steel matrix under the investigated immersion period. Inclusions with little Si, such as Al–Mg–Ca–O enriched inclusions, totally disappear after certain immersion time. During the immersion, the corrosion product tends to deposit at the interstice between the inclusion and steel matrix. - Highlights: • Ex situ characterization of metallurgical inclusions in X100 pipeline steel. • The pipeline steel was immersed in neutral pH bicarbonate solution. • Majority of inclusions remain stable during the whole testing time. • The chemical stability of metallurgical inclusions depends on the SiO{sub 2

  1. Ex situ characterization of metallurgical inclusions in X100 pipeline steel before and after immersion in a neutral pH bicarbonate solution

    International Nuclear Information System (INIS)

    Li, Yingbo; Liu, Jie; Deng, Yida; Han, Xiaopeng; Hu, Wenbin; Zhong, Cheng

    2016-01-01

    The initiation of corrosion pits in pipeline steels plays an important role in the development of stress corrosion cracking. In order to reveal the effect of inclusions on corrosion initiation sites and also to clarify contradictory results from previous literature, we proposed an ex situ characterization method that is allowed to characterize exactly the same inclusion or location of the surface of steel before and after corrosion tests. The time-dependent corrosion behaviour of the inclusions and the surrounding X100 steel matrix at the same area before and after early stage immersion in a near-neutral pH bicarbonate solution was investigated by ex situ scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis and localized electrochemical impedance spectroscopy (LEIS). The sizes of most inclusions in X100 steel are below 3 μm. The results challenge the long-held opinion of previous work that corrosion pit initiations are related with the inclusions. It has been found that most of the inclusions remain stable (intact) during the whole testing time although severe corrosion occurs on the matrix of the steel. The chemical composition of the inclusion greatly affects the chemical stability of the inclusion. SiO 2 inclusions and complex inclusions with a high SiO 2 content remain intact although obvious general corrosion occurs on the steel matrix under the investigated immersion period. Inclusions with little Si, such as Al–Mg–Ca–O enriched inclusions, totally disappear after certain immersion time. During the immersion, the corrosion product tends to deposit at the interstice between the inclusion and steel matrix. - Highlights: • Ex situ characterization of metallurgical inclusions in X100 pipeline steel. • The pipeline steel was immersed in neutral pH bicarbonate solution. • Majority of inclusions remain stable during the whole testing time. • The chemical stability of metallurgical inclusions depends on the SiO 2 content.

  2. ALTERNATIVE BINDERS TO BENTONITE FOR IRON ORE PELLETIZING : PART II : EFFECTS ON METALLURGICAL AND CHEMICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Osman Sivrikaya

    2014-07-01

    Full Text Available This study was started to find alternative binders to bentonite and to recover the low preheated and fired pellet mechanical strengths of organic binders-bonded pellets. Bentonite is considered as a chemical impurity for pellet chemistry due to acid constituents (SiO2 and Al2O3. Especially addition of silica-alumina bearing binders is detrimental for iron ore concentrate with high acidic content. Organic binders are the most studied binders since they are free in silica. Although they yield pellets with good wet strength; they have found limited application in industry since they fail to give sufficient physical and mechanical strength to preheated and fired pellets. It is investigated that how insufficient preheated and fired pellet strengths can be improved when organic binders are used as binder. The addition of a slag bonding/strength increasing constituent (free in acidic contents into pellet feed to provide pellet strength with the use of organic binders was proposed. Addition of boron compounds such as colemanite, tincal, borax pentahydrate, boric acid together with organic binders such as CMC, starch, dextrin and some organic based binders, into magnetite and hematite pellet mixture was tested. After determining the addition of boron compounds is beneficial to recover the low pellet physical and mechanical qualities in the first part of this study, in this second part, metallurgical and chemical properties (reducibility - swelling index – microstructure – mineralogy - chemical content of pellets produced with combined binders (an organic binder plus a boron compound were presented. The metallurgical and chemical tests results showed that good quality product pellets can be produced with combined binders when compared with the bentonite-bonded pellets. Hence, the suggested combined binders can be used as binder in place of bentonite in iron ore pelletizing without compromising the pellet chemistry.

  3. Metallurgical study and phase diagram calculations of the Zr-Nb-Fe-(Sn,O) system

    International Nuclear Information System (INIS)

    Toffolon, C.

    2000-01-01

    The Framatome M5 TM Zr-Nb-O alloy with small amounts of Fe is of interest for nuclear applications (PWR fuel cladding).The behaviour of this kind of alloy for in-service conditions strongly depends on the microstructure. Therefore, a metallurgical study of alloys of the Zr-Nb-Fe-(O-Sn) system has been developed in order to study the influence of chemical composition variabilities of Nb, Fe and O and thermal treatments on the resultant microstructure. In order to get some insight on the physical metallurgy of Zr-Nb-Fe-(Sn,O) alloys and to minimize the experiments, it is useful to build a thermodynamic database. With this object, it was necessary to re-optimize and to calculate the low order binary systems such as Fe-Nb and Nb-Sn in order to assess the Zr-Nb-Fe-(Sn,O) system. Then, the experimental studies concerned: the influence of small variations in Nb and O contents on the α/β transus temperatures. A comparison between experimental results and thermodynamic predictions showed a good agreement; the precipitation kinetics of βNb and intermetallic phases in the α phase domain. These experiments showed that the kinetics depends on the initial metallurgical conditions; the determination of the crystallographic structure and the stoichiometry of the ternary Zr-Nb-Fe intermetallic compounds as a function of the temperature. Finally, these experimental data were used to propose a first assessment of the Zr-Nb-Fe(O∼1200 ppm) system. (author)

  4. Manganese Ores from South Sulawesi: Their Potential Uses as Raw Materials for Metallurgical Industry

    Directory of Open Access Journals (Sweden)

    Sufriadin Sufriadin

    2017-03-01

    Full Text Available Characterization of manganese ores from Barru and Bone regencies of South Sulawesi has been conducted with the aim at clarification of their mineralogical and chemical composition for their potential uses as the raw materials for metallurgical industry. Mineralogical properties of the ores analyzed by means of optical microscopy and X-ray diffractometry (XRD show that samples from Barru consist mainly of rhodochrosite (MnCO3 with less cryptomelane, groutite, bixbyite, and todorokite. Goethite, calcite and small amount of quartz present as impurities. Manganese ore samples from Bone are predominantly composed of pyrolusite (MnO2 with subordinate ramsdellite and hollandite. Barite, quartz, hematite and clay are present as gangue minerals. Chemical compositions determined by using XRF method revealed that Barru samples contain higher in MnO (average is 40.07 wt% than the Bone samples (average is 34.36 wt%. Similarly, Fe2O3 and CaO are also higher in Barru than those of the Bone samples. In contrast, concentrations of SiO2 and total alkali (K2O + Na2O are lower in the Barru samples. The average P2O5 content of samples in both areas is low (<0.2 wt%. Relatively higher grade of Fe2O3 in the Barru ore implies that it has potential application for ferromanganese production; whereas the elevated SiO2 content of the Bone ore is a good indication for silicomanganese manufacture. However, both ores may not favorable to be directly used as raw materials in metallurgical uses. Prior to be used, the ores should be treated by applying physical beneficiation in order to reduce deleterious elements.

  5. Corrosion behaviour of hyper duplex stainless steel in various metallurgical conditions for sea water cooled condensers

    International Nuclear Information System (INIS)

    Singh, Umesh Pratap; Kain, Vivekanand; Chandra, Kamlesh

    2011-01-01

    The sea water cooled condensers have to resist severe corrosion as marine environment is the most corrosive natural environment. Copper alloys are being phased out due to difficulties in water chemistry control and Titanium base alloys are extremely expensive. Austenitic stainless steels (SS) remain prone to localized corrosion in marine environments hence not suitable. These heat exchangers operate at temperatures not exceeding 50 deg C and at very low pressures. The tubes of these heat exchangers are joined to the carbon steel tube sheets by roll expansion or by roll expansion followed by seam welding. These conditions are expected to affect the localized corrosion resistance of the tube in roll joined region due to cold working and in the tube-tube sheet welded joint due to thermal effects of welding. In this study, the localized corrosion behaviour of a Hyper Duplex Stainless Steel (HDSS) has been evaluated, and compared with other materials e.g. types 304L SS, 316L SS, Duplex SS 2205, Titanium grade - 2, and Al Brass. The evaluation is done in three metallurgical conditions (a) as received, (b) cold rolled and (c) welded condition in synthetic sea water at room temperature and at 50 deg C to assess the resistance to crevice, pitting and stress corrosion cracking using standard ASTM exposure and electrochemical techniques. The results provide comparative assessment of these alloys and show their susceptibility in the three metallurgical conditions as encountered in condensers. Hyper-duplex SS has been shown to be highly resistant in sea water for the condenser tubing application. (author)

  6. Analysis of Chemical Composition of Non-Ferrous Metal Items from the Ananyino Burial Ground

    Directory of Open Access Journals (Sweden)

    Saprykina Irina А.

    2016-03-01

    Full Text Available The article presents results of an analysis conducted by the authors in order to study chemical composition of items from non-ferrous metals found on the Ananyino burial ground. A number of research methods, including OES, XRF and TXRF was applied to study a selection of 387 samples of arrow- and spearheads, celts, tail-pieces, warhammers, poleaxes, knives and daggers, as well as items of attire and jewelry, some sporadic details of harness and bridle. The fi ndings are quite comparable. The results were classifi ed by the geochemical principle of 1,0% alloyage threshold. It was found out that the sample primarily consists of copper items, including “pure” copper and copper with a wide range of trace elements (particularly, Ni, As, Sb. The core (48% consists of copper items with traces of antimony and arsenic, or “pure” copper (7%, tin or triple bronze (40%; it also includes some other types of alloys based on copper or silver (5%. As the analysis has shown, complex ores seem to be the most probable source of copper. Traditionally, the Urals, the Sayan and the Altay Mountains, Kazakhstan and the Northern Caucasus were regarded as the most probable minefi elds to supply ores to the barren regions of Eastern Europe. While ore sources for products made of metallurgical “pure” copper are localized within the Ural mining and metallurgical region, metal sources for items cast from different groups of alloys (rather than imports of ready-made products require further research.

  7. Importance of doping, dopant distribution, and defects on electronic band structure alteration of metal oxide nanoparticles: Implications for reactive oxygen species.

    Science.gov (United States)

    Saleh, Navid B; Milliron, Delia J; Aich, Nirupam; Katz, Lynn E; Liljestrand, Howard M; Kirisits, Mary Jo

    2016-10-15

    Metal oxide nanoparticles (MONPs) are considered to have the potency to generate reactive oxygen species (ROS), one of the key mechanisms underlying nanotoxicity. However, the nanotoxicology literature demonstrates a lack of consensus on the dominant toxicity mechanism(s) for a particular MONP. Moreover, recent literature has studied the correlation between band structure of pristine MONPs to their ability to introduce ROS and thus has downplayed the ROS-mediated toxicological relevance of a number of such materials. On the other hand, material science can control the band structure of these materials to engineer their electronic and optical properties and thereby is constantly modulating the pristine electronic structure. Since band structure is the fundamental material property that controls ROS-producing ability, band tuning via introduction of dopants and defects needs careful consideration in toxicity assessments. This commentary critically evaluates the existing material science and nanotoxicity literature and identifies the gap in our understanding of the role of important crystal structure features (i.e., dopants and defects) on MONPs' electronic structure alteration as well as their ROS-generation capability. Furthermore, this commentary provides suggestions on characterization techniques to evaluate dopants and defects on the crystal structure and identifies research needs for advanced theoretical predictions of their electronic band structures and ROS-generation abilities. Correlation of electronic band structure and ROS will not only aid in better mechanistic assessment of nanotoxicity but will be impactful in designing and developing ROS-based applications ranging from water disinfection to next-generation antibiotics and even cancer therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Immobilization of heavy metals (Pb, Cu, Cr, Zn, Cd, Mn) in the mineral additions containing concrete composites.

    Science.gov (United States)

    Giergiczny, Zbigniew; Król, Anna

    2008-12-30

    The presented work determines the level of heavy metals (Pb+2, Cu+2, Zn+2, Cr+6, Cd+2, Mn+2) immobilization in the composites produced using Ordinary Portland Cement (OPC) as well as of binders containing large amount of mineral additives in its composition-siliceous fly ash (FA), fluidized bed combustion ash (FFA) and ground granulated blast furnace slag (GGBFS). Heavy metals were introduced to cementitious materials in the form of soluble salts as well as components of hazardous wastes (medical ash, metallurgical dust). It has been stated, that the level of heavy metals immobilization is combined with composites composition. Majority of analyzed heavy metals, added to binders' composition in the form of heavy metal salts achieves high level of immobilization, in mortar based on binder with 85% GGBFS and 15% OPC. The lowest immobilization level was reached for chromium Cr+6 added to hardening mortars as Na2Cr2O72H2O. The level ranges from 85.97% in mortars made on blended binder (20% OPC, 30% FFA and 50% GGBFS) to 93.33% in mortar produced on OPC. The increase of the so-called immobilization degree with time of hardened material maturing was found. This should be attributed to the pozzolanic or pozzolanic/hydraulic properties of components used; their effect on microstructure of hardened material is also important. Mineral additions enter the hydration reactions in the mixtures and favor the formation of specific microstructure promoting the immobilization of hazardous elements.

  9. Investigations on thermal properties, stress and deformation of Al/SiC metal matrix composite based on finite element method

    Directory of Open Access Journals (Sweden)

    K. A. Ramesh Kumar

    2014-09-01

    Full Text Available AlSiC is a metal matrix composite which comprises of aluminium matrix with silicon carbide particles. It is characterized by high thermal conductivity (180-200 W/m K, and its thermal expansion are attuned to match other important materials that finds enormous demand in industrial sectors. Although its application is very common, the physics behind the Al-SiC formation, functionality and behaviors are intricate owing to the temperature gradient of hundreds of degrees, over the volume, occurring on a time scale of a few seconds, involving multiple phases. In this study, various physical, metallurgical and numerical aspects such as equation of continuum for thermal, stress and deformation using finite element (FE matrix formulation, temperature dependent material properties, are analyzed. Modelling and simulation studies of Al/SiC composites are a preliminary attempt to view this research work from computational point of view.

  10. An assessment and evaluation for recycle/reuse of contaminated process and metallurgical equipment at the DOE Rocky Flats Plant Site -- Building 865. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    An economic analysis of the potential advantages of alternatives for recycling and reusing equipment now stored in Building 865 at the Rocky Flats Plant (RFP) in Colorado has been conducted. The inventory considered in this analysis consists primarily of metallurgical and process equipment used before January 1992, during development and production of nuclear weapons components at the site. The economic analysis consists of a thorough building inventory and cost comparisons for four equipment dispositions alternatives. The first is a baseline option of disposal at a Low Level Waste (LLW) landfill. The three alternatives investigated are metal recycling, reuse with the government sector, and release for unrestricted use. This report provides item-by-item estimates of value, disposal cost, and decontamination cost. The economic evaluation methods documented here, the simple cost comparisons presented, and the data provided as a supplement, should provide a foundation for D&D decisions for Building 865, as well as for similar D&D tasks at RFP and at other sites.

  11. Metallurgical production from North-east of the Iberian Peninsula during III millennium cal. BC: the Bauma del Serrat del Pont (Tortellá, Girona workshop

    Directory of Open Access Journals (Sweden)

    Alcalde, Gabriel

    1998-06-01

    Full Text Available We examine the third millennium cal. BC levels from the small rockshelter of Bauma del Serrat del Pont. The site was settled by a small group, building a perishable structure except in the II. 5 level. Some evidence suggests a seasonal occupation of the site. Multidisciplinary research shows a broad spectrum of local resources involved in the dairy life of this people, including those related to metallurgical activity. We find very old tin alloys, plain or bell beaker decorated pot-furnaces (used to smelt copper ores and clay tuyeres.

    Se presentan los resultados de la excavación en los niveles del III milenio cal. AC del pequeño abrigo rocoso de la Bauma del Serrat del Pont. El yacimiento fue ocupado por un grupo pequeño que organizó el espacio interno con una estructura de material perecedero, excepto en el nivel II.5. Algunos datos indican que las ocupaciones pudieron tener un carácter estacional. Los estudios multidisciplinares reconstruyen un aprovechamiento diversificado de recursos locales, entre los que se integran los dedicados a las tareas metalúrgicas. Se documentan aleaciones intencionadas de bronce de gran antigüedad, el empleo de vasijas horno con o sin decoración campaniforme, y toberas de arcilla.

  12. An assessment and evaluation for recycle/reuse of contaminated process and metallurgical equipment at the DOE Rocky Flats Plant Site -- Building 865

    International Nuclear Information System (INIS)

    1993-08-01

    An economic analysis of the potential advantages of alternatives for recycling and reusing equipment now stored in Building 865 at the Rocky Flats Plant (RFP) in Colorado has been conducted. The inventory considered in this analysis consists primarily of metallurgical and process equipment used before January 1992, during development and production of nuclear weapons components at the site. The economic analysis consists of a thorough building inventory and cost comparisons for four equipment dispositions alternatives. The first is a baseline option of disposal at a Low Level Waste (LLW) landfill. The three alternatives investigated are metal recycling, reuse with the government sector, and release for unrestricted use. This report provides item-by-item estimates of value, disposal cost, and decontamination cost. The economic evaluation methods documented here, the simple cost comparisons presented, and the data provided as a supplement, should provide a foundation for D ampersand D decisions for Building 865, as well as for similar D ampersand D tasks at RFP and at other sites

  13. Maintaining and increasing the contribution made to South Africa by the minerals and metals industry

    International Nuclear Information System (INIS)

    Jochens, P.R.

    1985-01-01

    This review article first highligts the past performance of the industry and discusses the manner in which the development of the industry has followed a logical progression from mining to the production of mineral and metal products of specification purity. Then the numerous constraints against a greater contribution by the industry are enumerated. Attention is drawn to the extent of further processing that can be undertaken in the context of mining and metallurgical processing, not only to indicate the benefits that can be derived from the added-value conferred on a mineral or metal commodity during each stage of its further processing, but also to point out some important corollaries of further processing. The many opportunities and challenges for an increased contribution by the minerals and metals industry are then reviewed. This major section includes a list of commodities for which increased penetration of export markets could be sought because the increasing resistance level (a term developed in this paper) has not been attained: a list of commodities that are imported at present, many of which could be produced locally on the basis of identified resources and expertise; a list of commodities for which additional uses should be developed so that South Africa, which possesses the largest reserves and is the largest exporter, can increase its production rate; and examples of commodities for which further processing is still at an early stage

  14. Restenosis in coronary bare metal stents. Importance of time to follow-up: a comparison of coronary angiograms 6 months and 4 years after implantation

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Helqvist, Steffen; Kløvgaard, Lene

    2008-01-01

    Objectives. Angiographic late lumen loss measured 6 to 9 month after bare metal stent implantation in the coronary arteries is a validated restenosis parameter. Design. We performed a second angiographic follow-up after 4 years in event free survivors from the DANSTENT trial cohort. Results......-sectional vessel area and a 39% reduction of the binary restenosis rate over time. Conclusions. Instent late lumen loss in bare metal stents decreases spontaneously over time. Maturation of early hyperplastic tissue reaction after stent implantation with subsequent thinning of fibrotic tissue might explain...

  15. Thermo-mecano-metallurgical modelling of welding: application to welded joints in nuclear power plants

    International Nuclear Information System (INIS)

    Cosimo, Alejandro

    2014-01-01

    The Thermo-Mecano-Metallurgical (TMM) modelling of welding is considered in this thesis, where the high non-linearity and the multiphysics character of the problem makes necessary to study different areas of Computational Mechanics. Each of the main problems, specifically the thermal, the mechanical and the metallurgical problems, are separately investigated. In the context of Computational Welding Mechanics (CWM), their coupling is solved by means of a staggered approach making the hypothesis that they are weakly-coupled. In the case of the thermal problem, the primary complication is stated by the solid/liquid phase change. Classical formulations dealing with the solution of this problem suffer from instabilities associated to the discontinuity of the temperature gradient at the phase change boundary. This issue is studied in this work by considering an enriched finite element formulation with the ability of representing the gradient discontinuity inside finite elements. It is remarked that the proposed method avoids the use of an auxiliary equation to determine the enrichment position, which is common for level set formulations. The mechanical behaviour of bodies during solidification is revisited and implemented as part of the Finite Element (FE) framework OOFELIE. When possible, microstructure evolution must be considered in order to correctly predict Weld Residual Stresses (WRS). In this context, the implementation of a particular model for predicting microstructure evolution comes in association with the restriction that it can be applied to a reduced number of materials. In order to deal with this issue, the conception of a computational tool flexible enough to describe a wide range of materials is undertaken. Additionally, a model describing the Titanium alloy Ti6Al4V is particularly considered. The high computational cost of welding problems is addressed by means of the formulation of Hyper-Reduced Order Models (HROMs), and the parallelization of the FE

  16. USING THE OUTSOURCING MECHANISM TO INCREASE THE EFFICIENCY OF REPAIR AND MAINTENANCE IN METALLURGICAL ENTERPRISES

    Directory of Open Access Journals (Sweden)

    Elena I. Kozlova

    2017-01-01

    Full Text Available Abstract. Objectives The aim of the work is to study the outsourcing mechanism from the point of view of increasing the efficiency of repair and maintenance at a metallurgical enterprise. Method Analysis of the experience of using outsourcing of repair services at domestic and foreign metallurgical enterprises was carried out. Analysis of the experience of the withdrawal from enterprise repair services into a separate outsourcing company has shown that the main advantages of this method of organising repair activities are an increase in the transparency of the costs of repairs and maintenance, and hence their reduction, as well as a reduction in the amount of equipment downtime. The main characteristics of outsourcing were revealed, substantiating its expediency. The restructuring of the repair system provides a step-by-step transition from decentralised to centralised structures of technical, mechanical, power and electrical repair services of enterprises, from the principle of "self-service" to the principle of "proprietary service" by isolating the subdivisions of the repair system from the structure of enterprises and creating competing members of the repair services market. Put another way, this is typified by moving away from the status of auxiliary production to a selfdependent activity. The stages of outsourcing the repair services of the enterprise are considered and possible problems that may arise in the course of the work of a working group are established to determine the suitability of outsourcing and to resolve the numerous issues arising from the transfer of repair functions. Results The findings of the research include approaches developed for overcoming risky situations: providing guarantees from the customer and the contractor and indicating them in the contract, increasing the motivation of the outsourcing company through a key performance indicator that should increase the interest of the performer in providing quality

  17. Nutrient and dissolved organic carbon removal from water using mining and metallurgical by-products.

    Science.gov (United States)

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2012-05-15

    Excess nutrient input to water bodies frequently results in algal blooms and development of oxygen deficient conditions. Mining or metallurgical by-products can potentially be utilised as filtration media within water treatment systems such as constructed wetlands, permeable reactive barriers, or drain liners. These materials may offer a cost-effective solution for the removal of nutrients and dissolved organic carbon (DOC) from natural waters. This study investigated steel-making, alumina refining (red mud and red sand) and heavy mineral processing by-products, as well as the low-cost mineral-based material calcined magnesia, in laboratory column trials. Influent water and column effluents were analysed for pH and flow rate, alkalinity, nutrient species and DOC, and a range of major cations and anions. In general, by-products with high Ca or Mg, and to a lesser extent those with high Fe content, were well-suited to nutrient and DOC removal from water. Of the individual materials examined, the heavy mineral processing residue neutralised used acid (NUA) exhibited the highest sorption capacity for P, and removed the greatest proportions of all N species and DOC from influent water. In general, NUA and mixtures containing NUA, particularly those with calcined magnesia or red mud/red sand were the most effective in removing nutrients and DOC from influent water. Post-treatment effluents from columns containing NUA and NUA/steel-making by-product, NUA/red sand and NUA/calcined magnesia mixtures exhibited large reductions in DOC, P and N concentrations and exhibited a shift in nutrient ratios away from potential N- and Si-limitation and towards potential P-limitation. If employed as part of a large-scale water treatment scheme, use of these mining and metallurgical by-products for nutrient removal could result in reduced algal biomass and improved water quality. Identification and effective implementation of mining by-products or blends thereof in constructed wetlands

  18. M-Area and Metallurgical Laboratory Hazardous Waste Management Facilities groundwater monitoring and corrective-action report (U). Third and fourth quarters 1996, Vol. I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report describes the groundwater monitoring and corrective-action program at the M-Area Hazardous Waste Management Facility (HWMF) and the Metallurgical Laboratory (Met Lab) HWMF at the Savannah River Site (SRS) during 1996.

  19. Laser-induced change of electrical resistivity of metals and its applications

    Science.gov (United States)

    Pawlak, Ryszard; Kostrubiec, Franciszek; Tomczyk, Mariusz; Walczak, Maria

    2005-01-01

    Applying of laser alloying for modification of electrical resistivity of metals with significant importance in electrical and electronic engineering and utilization of this method for producing passive elements of electric circuit have been presented. The alloyed metals were obtained by means of laser beams with different wave length and various mode of working (cw or pulse), by different methods for the supplying of alloying elements. It was possible to form alloyed layers of metals forming different types of metallurgical systems: with full (Cu-Au, Cu-Ni) or partial solubility (Mo-Ni, W-Ni, Cu-Al, Ag-Sn), insoluble (Mo-Au and Cu-Cr) and immiscible (Ag-Ni and Ni-Au) metals, with metallic as well as non-metallic additions (oxide). It has been shown as well that it is possible to achieve resistive elements modified in whole cross section, in a single technological process. The results of systematic investigations into the resistivity of alloyed metals in the temperature range of 77-450 K have been presented. The alloyed layers, obtained, were characterised by a range of resistivity from 2.8 x 10-8 Ωm (Cu-Cr) to 128 x 10-8 Ωm (W-Ni). The microstructure and composition of alloyed layers were examined by means of SEM-microscopy and EDX analyser. In selected cases it was shown how results of investigations could be utilized for modification of surface layer of contact materials or to optimize the resistance of laser welded joints. In addition the results of investigations of new developed microtechnology -- producing micro-areas with extremely high resistivity -- have been presented.

  20. Stress and toxicity of biologically important transition metals (Co, Ni, Cu and Zn) on phytoplankton in a tropical freshwater system: An investigation with pigment analysis by HPLC

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Babu, P.V.R.; Acharyya, T.; Bandyopadhyay, D.

    (-9) to 1 x 10 sup(-8) M) did not show a dramatic change in the total biomass or concentrations of the pigment markers. At concentration of 1 x 10 sup(-7) M of metal, Cu acted as a nutrient and helped to increase the biomass followed by Co, Ni and Zn...

  1. Gamma Prime Morphology and Creep Properties of Nickel Based Superalloys With Platinum Group Metal Additions (Preprint)

    Science.gov (United States)

    2008-04-01

    Cobalt on the Tensile and Stress Rupture Properties of the Nickel-Base Superalloy MAR-M247,” Metallurgical Transactions A, 13 (A) (1982), 1767-1774.           10 ...AFRL-RX-WP-TP-2008-4320 GAMMA PRIME MORPHOLOGY AND CREEP PROPERTIES OF NICKEL BASED SUPERALLOYS WITH PLATINUM GROUP METAL ADDITIONS...AND SUBTITLE GAMMA PRIME MORPHOLOGY AND CREEP PROPERTIES OF NICKEL BASED SUPERALLOYS WITH PLATINUM GROUP METAL ADDITIONS (PREPRINT) 5a.

  2. A comparison of the metallurgical behaviour of dispersion fuels with uranium silicides and U6Fe as dispersants

    International Nuclear Information System (INIS)

    Nazare, S.

    1984-01-01

    In the past few years metallurgical studies have been carried out to develop fuel dispersions with U-densities up to 7.0 Mg U m -3 . Uranium silicides have been considered to be the prime candidates as dispersants; U 6 Fe being a potential alternative on account of its higher U-density. The objective of this paper is to compare the metallurgical behaviour of these two material combinations with regard to the following aspects: (1) preparation of the compounds U 3 Si, U 3 Si 2 and U 6 Fe; (2) powder metallurgical processing to miniature fuel element plates; (3) reaction behaviour under equilibrium conditions in the relevant portions of the ternary U-Si-Al and U-Fe-Al systems; (4) dimensional stability of the fuel plates after prolonged thermal treatment; (5) thermochemical behaviour of fuel plates at temperatures near the melting point of the cladding. Based on this data, the possible advantages of each fuel combination are discussed. (author)

  3. Mechanical and Metallurgical Properties of Various Nickel-Titanium Rotary Instruments

    Directory of Open Access Journals (Sweden)

    Kyu-Sang Shim

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of thermomechanical treatment on mechanical and metallurgical properties of nickel-titanium (NiTi rotary instruments. Eight kinds of NiTi rotary instruments with sizes of ISO #25 were selected: ProFile, K3, and One Shape for the conventional alloy; ProTaper NEXT, Reciproc, and WaveOne for the M-wire alloy; HyFlex CM for the controlled memory- (CM- wire; and TF for the R-phase alloy. Torsional fracture and cyclic fatigue fracture tests were performed. Products underwent a differential scanning calorimetry (DSC analysis. The CM-wire and R-phase groups had the lowest elastic modulus, followed by the M-wire group. The maximum torque of the M-wire instrument was comparable to that of a conventional instrument, while those of the CM-wire and R-phase instruments were lower. The angular displacement at failure (ADF for the CM-wire and R-phase instruments was higher than that of conventional instruments, and ADF of the M-wire instruments was lower. The cyclic fatigue resistance of the thermomechanically treated NiTi instruments was higher. DSC plots revealed that NiTi instruments made with the conventional alloy were primarily composed of austenite at room temperature; stable martensite and R-phase were found in thermomechanically treated instruments.

  4. Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Jr, J W; Spaletta, H W

    1984-08-01

    Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities.

  5. Development and characterization of powder metallurgically produced discontinuous tungsten fiber reinforced tungsten composites

    Science.gov (United States)

    Mao, Y.; Coenen, J. W.; Riesch, J.; Sistla, S.; Almanstötter, J.; Jasper, B.; Terra, A.; Höschen, T.; Gietl, H.; Bram, M.; Gonzalez-Julian, J.; Linsmeier, Ch; Broeckmann, C.

    2017-12-01

    In future fusion reactors, tungsten is the prime candidate material for the plasma facing components. Nevertheless, tungsten is prone to develop cracks due to its intrinsic brittleness—a major concern under the extreme conditions of fusion environment. To overcome this drawback, tungsten fiber reinforced tungsten (Wf/W) composites are being developed. These composite materials rely on an extrinsic toughing principle, similar to those in ceramic matrix composite, using internal energy dissipation mechanisms, such as crack bridging and fiber pull-out, during crack propagation. This can help Wf/W to facilitate a pseudo-ductile behavior and allows an elevated damage resilience compared to pure W. For pseudo-ductility mechanisms to occur, the interface between the fiber and matrix is crucial. Recent developments in the area of powder-metallurgical Wf/W are presented. Two consolidation methods are compared. Field assisted sintering technology and hot isostatic pressing are chosen to manufacture the Wf/W composites. Initial mechanical tests and microstructural analyses are performed on the Wf/W composites with a 30% fiber volume fraction. The samples produced by both processes can give pseudo-ductile behavior at room temperature.

  6. Synergetic use of lignite fly ash and metallurgical converter slag in geopolymer concrete

    Directory of Open Access Journals (Sweden)

    Gábor Mucsi

    2014-08-01

    Full Text Available The application and utilization of the industrial wastes and by-products in the construction industry is a key issue from an environmental and economic point of view. The increased use of lignite has substantially increased the available quantities of lignite fired power plant fly ash, which can be mainly classified as class C fly ash. The utilization of such raw material however has some difficulties. In the present paper lignite fired power station fly ash and metallurgical converter slag were used for the production of geopolymer concrete. The fly ash was used as a geopolymer based binder material, and a converter slag as aggregate, thus created a geopolymer concrete which contains mainly industrial wastes. As preliminary test experimental series were carried out using andesite as aggregate. The optimal aggregate/binder ratio was determined. The effect of the amount of alkaline activator solution in the binder, the aggregate type on the geopolymer concretes’ compressive strength and density was investigated. Furthermore, the physical properties - freeze-thaw resistance and particle size distribution - of the applied aggregates were measured as well. As a result of the experiments it was found that physical properties of the andesite and converter slag aggregate was close. Therefore andesite can be replaced by converter slag in the concrete mixture. Additionally, geopolymer concrete with nearly 20 MPa compressive strength was produced from class C fly ash and converter slag.

  7. Influence of metallurgical heterogeneities on the mechanisms of hydrogen diffusion and trapping of in nickel

    International Nuclear Information System (INIS)

    Oudriss, Abdelali

    2012-01-01

    A thorough investigation on the influence of several metallurgical defects on the hydrogen diffusion and trapping was conducted on nickel. This work was conducted towards two scientific orientations. A first approach was to assess the impact of intrinsic defects, especially grain boundaries and geometrically necessary dislocations on the hydrogen transport and segregation mechanisms. Combining microstructural characterizations with electrochemical permeation tests and thermal desorption spectroscopy, it has established that the grain boundaries with ordered structure called 'special grain boundaries' are preferential areas for hydrogen segregation. On the other hand, a second category of grain boundaries called 'general' or 'random' with high free volume and disordered structure are promoters for hydrogen diffusion, and they represent the main sources of the phenomena short circuit diffusion reported in the face-centered cubic materials. The second approach of this work consisted in the study of the interaction of hydrogen with the plastic deformation heterogeneities. The electrochemical permeation tests performed on microstructures obtained by deformation showed that for the traction monotonous, the equiaxed cells and walls of dislocations are the potential traps for hydrogen and they slow its transport, this latter is mainly provided by the interstitial diffusion mechanism. In addition, for fatigue microstructure, rapid diffusivity of hydrogen was recorded, and suggesting that a phenomenon similar to short-circuit diffusion is involved in the transport of hydrogen. On two approaches, the results suggest a contribution of hydrogen in the formation of vacancies. (author) [fr

  8. Powder metallurgical low-modulus Ti-Mg alloys for biomedical applications.

    Science.gov (United States)

    Liu, Yong; Li, Kaiyang; Luo, Tao; Song, Min; Wu, Hong; Xiao, Jian; Tan, Yanni; Cheng, Ming; Chen, Bing; Niu, Xinrui; Hu, Rong; Li, Xiaohui; Tang, Huiping

    2015-11-01

    In this work, powder metallurgical (PM) Ti-Mg alloys were prepared using combined techniques of mechanical alloying and spark plasma sintering. The alloys mainly consist of super saturations of Mg in Ti matrix, and some laminar structured Ti- and Mg-rich phases. The PM Ti-Mg alloys contain a homogeneous mixtures of nanocrystalline Mg and Ti phases. The novel microstructures result in unconventional mechanical and biological properties. It has been shown that the PM Ti-Mg alloys have a much lower compression modulus (36-50GPa) compared to other Ti alloys, but still remain a very high compressive strength (1500-1800MPa). In addition, the PM Ti-Mg alloys show good biocompatibility and bioactivity. Mg can dissolve in the simulated body fluids, and induce the formation of the calcium phosphate layer. The compression modulus of PM Ti-Mg alloys decreases with the amount of Mg, while the bioactivity increases. Although the corrosion resistance of Ti-Mg alloys decreases with the content of Mg, the alloys still show good stability in simulated body fluid under electrochemical conditions. The indirect and direct cytotoxicity results show that PM Ti-Mg alloys have a good biocompatibility to NIH-3T3 cells. Therefore, the PM Ti-Mg alloys are promising candidates in biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. A CFD study on the dust behaviour in a metallurgical waste-heat boiler

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yongxiang; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1997-12-31

    A waste-heat boiler forms an essential part for the treatment of high temperature flue-gases in most metallurgical processes. Flue-dust carried by the furnace off-gas has to be captured efficiently in the waste-heat boilers before entering the downstream gas purification equipment. Flue dust may accumulate and foul on the heat transfer surfaces such as tube-walls, narrow conjunctions between the boiler and the furnace uptake, and thus may cause smelter shutdown, and interrupt the production. A commercial CFD package is used as the major tool on modelling the dust flow and settling in the waste-heat boiler of an industrial copper flash smelter. In the presentation, dust settling behaviour is illustrated for a wide range of particle sizes, and dust capture efficiency in the radiation section of the boiler for different particle sizes has been shown with the transient simulation. The simulation aims at providing detailed information of dust behaviour in the waste-heat boiler in sulphide smelting. (author) 11 refs.

  10. Metallurgical aspects of fatigue fractured surfaces of al grain refined by some rare earth materials

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2005-01-01

    Aluminum and aluminum alloys are widely used materials in the automobile and air craft industries due to their high strength-to-weight ratio, in addition to some other attractive characteristics e.g. corrosion resistance and high electrical and thermal conductivities. Aluminum and its alloys are normally grain refined by Ti or Ti+B to enhance their surface quality and improve their mechanical strength. Although the effect of addition of these grain refiners on the microstructure mechanical behaviour has been investigated and reported, little work has been published on the effect of the refiners on the fatigue life of aluminum and its alloys. In this paper, the effect of addition of some rare earth materials, namely Vanadium and Zirconium on the fatigue life of commercially pure aluminum grain refined by Ti or Ti+B is reported and discussed. Furthermore, metallurgical aspects of these elements on the fatigue fractured surfaces are also discussed using scanning electron microscopy, SEM. Finally, photoscans of the fractured surfaces at different fatigue stresses are presented and discussed. (author)

  11. Determination of nanoscale particles in the air of working zone at the metallurgical production

    Directory of Open Access Journals (Sweden)

    Т.S. Ulanova

    2015-03-01

    Full Text Available The results of studies of the air of working zone at the metallurgical production on the example of Avisma OJSC (Berezniki, the Perm Territory for the content of nanoscale particles are specified. The maximum nanoparticles concentration in the range of 13523–28609 mln./m3 is determined at the working place of the titanium production smelter with the maximum size of particles of 10–15 nm. At the working place in the administrative building (reference working place the maximum concentration is determined within the range of 524–1000 mln./m3; the maximum size of nanoparticles is 20 nm. It was established that the number concentration of nanoparticles at the reference working places (administration of Avisma OJSC is significantly lower than at the working places of main production processes. The presented studies can be used as the additional factors in the assessment of labor conditions and occupational risk during the manufacture and use of materials containing nanoparticles as well as the production processes with the nanoparticles formation.

  12. Performance Analysis of a Grid-Connected Upgraded Metallurgical Grade Silicon Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Chao Huang

    2016-05-01

    Full Text Available Because of their low cost, photovoltaic (PV cells made from upgraded metallurgical grade silicon (UMG-Si are a promising alternative to conventional solar grade silicon-based PV cells. This study investigates the outdoor performance of a 1.26 kW grid-connected UMG-Si PV system over five years, reporting the energy yields and performance ratio and estimating the long-term performance degradation rate. To make this investigation more meaningful, the performance of a mono-Si PV system installed at the same place and studied during the same period of time is presented for reference. Furthermore, this study systematizes and rationalizes the necessity of a data selection and filtering process to improve the accuracy of degradation rate estimation. The impact of plane-of-array irradiation threshold for data filtering on performance ratio and degradation rate is also studied. The UMG-Si PV system’s monthly performance ratio after data filtering ranged from 84% to 93% over the observation period. The annual degradation rate was 0.44% derived from time series of monthly performance ratio using the classical decomposition method. A comparison of performance ratio and degradation rate to conventional crystalline silicon-based PV systems suggests that performance of the UMG-Si PV system is comparable to that of conventional systems.

  13. Production of highly porous glass-ceramics from metallurgical slag, fly ash and waste glass

    Directory of Open Access Journals (Sweden)

    Mangutova Bianka V.

    2004-01-01

    Full Text Available Glass-ceramics composites were produced based on fly-ash obtained from coal power stations, metallurgical slag from ferronickel industry and waste glass from TV monitors, windows and flasks. Using 50% waste flask glass in combination with fly ash and 20% waste glass from TV screens in combination with slag, E-modulus and bending strength values of the designed systems are increased (system based on fly ash: E-modulus from 6 to 29 GPa, and bending strength from 9 to 75 MPa. The polyurethane foam was used as a pore creator which gave the material porosity of 70(5% (fly ash-glass composite and a porosity of 65( 5% (slag-glass composite. E-modulus values of the designed porous systems were 3.5(1.2 GPa and 8.1(3 GPa, while the bending strength values were 6.0(2 MPa and 13.2(3.5 MPa, respectively. These materials could be used for the production of tiles, wall bricks, as well as for the construction of air diffusers for waste water aeration.

  14. Metallurgical examination of, and resin transfer from, Three Mile Island prefilter liners

    International Nuclear Information System (INIS)

    McConnell, J.W. Jr.; Spaletta, H.W.

    1984-08-01

    Metallurgical examinations were performed on two EPICOR-II prefilter liners at the Idaho National Engineering Laboratory (INEL) to determine conditions of the liners and identify the minimum expected lifetime of those and other liners stored at INEL. The research work was accomplished by EG and G Idaho, Inc. for the EPICOR-II Research and Disposition Program, which is funded by the US Department of Energy. The EPICOR-II prefilter liners were used to filter radionuclides from contaminated water during cleanup of Three Mile Island Unit 2 (TMI-2). The liners were constructed of carbon steel with a phenolic protective coating and contained organic and inorganic ion-exchange filtration media. Program plans call for interim storage of EPICOR-II prefilters at INEL for up to ten years, before final disposal in high integrity containers at the Hanford, Washington commercial disposal site. This report describes the (a) resin transfer process used to empty liners for examination, (b) removal of metallographic sections from those liners, (c) specimen preparation, and (d) findings from metallographic examination of those specimens. A minimum lifetime for the liners is determined and recommendations are given for storage of wastes from future TMI-2 activities

  15. Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Bernd; Sievers, Birte; Utzschneider, Sandra; Mueller, Peter; Jansson, Volkmar [Department of Orthopedic Surgery, Ludwig-Maximilians-University of Munich, Marchioninistrasse 15, 81377 Muenchen (Germany); Roessler, Sophie; Nies, Berthold [InnoTERE GmbH, Tatzberg 47, 01307 Dresden (Germany); Stephani, Guenter; Kieback, Bernd [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany); Quadbeck, Peter, E-mail: peter.quadbeck@ifam-dd.fraunhofer.de [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany)

    2011-12-15

    Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.

  16. Prospects for Ukrainian ferrous metals in the post-soviet period

    Science.gov (United States)

    Levine, R.M.; Bond, A.R.

    1998-01-01

    Two specialists on the mineral industries of the countries of the former USSR survey current problems confronting producers of ferrous metals in Ukraine and future prospects for domestic production and exports. A series of observations documenting the importance of ferrous metals production to Ukraine's economy is followed by sections describing investment plans and needs in the sector, and the role played by Ukraine within the iron and steel industry of the Soviet Union. The focus then turns to assessment of the current regional and global competitive position of Ukrainian producers for each of the major commodities of the sector-iron ore, manganese ore, ferroalloys, steel, and the products of the machine manufacturing and metal working industries. In conclusion, the paper discusses a potential regional industrial integration strategy analogous to that employed in the United States' Great Lakes/Midwest region, which possesses similar types of iron ore deposits and similar transport cost advantages and metallurgical and manufacturing industries. Journal of Economic Literature, Classification Numbers: F14, L61, L72. 1 table, 26 references.

  17. El Conocimiento de los Metales y su Beneficio por los Indígenas El Conocimiento de los Metales y su Beneficio por los Indígenas

    Directory of Open Access Journals (Sweden)

    Verónica de la Cruz Zamora Ayala

    2012-02-01

    Full Text Available The Mesoamerican cultural evolution was influenced by the Prehispanic metal work and metallurgy in many ways. It made possible much creative work that from that time to the present has been cause of admiration. The first manifestations were achieved in the western region of Mesoamerica where all this activity was originated producing sumptuary goods of gold and silver and copper instruments and other alloys. These metallurgical applications were wonderful creations from an esthetic and technical point of view. It is from this region that it is spread through out the rest of Mesoamerica achieving great importance at the beginning of the XVI century. In order to understand the advances reached by the mining and metallurgy industries during the prehispanic era and the implications of the development of this activity on the forth coming historical eras in the Mexican territory and particularly in Guanajuato, the authors offer a global panorama from the beginning and the conformation of the mining and metallurgic activities in Mesoamerica, the techniques used for the extraction and the processing of the minerals, the achieved artistic creations and the significance of such activities within the cultural context of Mesoamerica.La actividad minera y metalúrgica influyó en múltiples formas, en la evolución cultural mesoamericana e hizo posibles creaciones que hasta el presente son objeto de admiración. Sus primeras manifestaciones se produjeron en la región occidente de Mesoamérica, en donde adquirió gran presencia por haber sido el área puntera de dicha actividad, produciendo bienes suntuarios de oro y plata e instrumentos de cobre y otras aleaciones. Estas aplicaciones metalúrgicas son admirables tanto del punto de vista estético y técnico. Desde esta región se difunde hacia el resto de Mesoamérica adquiriendo gran importancia a principios del siglo XVI. A fin de comprender los avances que alcanzaron la minería y la metalurgia durante

  18. Metallurgical aspects of welding. Ferrous and nonferrous materials. 4. new rev. ed.; Die Metallurgie des Schweissens. Eisenwerkstoffe - nichteisenmetallische Werkstoffe

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Guenter

    2010-07-01

    This is the fourth edition of the standard work on welding metallurgy. The various problems of ferrous and nonferrous materials in the welding process are presented in great detail. In order to prevent corrosion of welded constructions, metallurgical properties and problems of all important technical materials are discussed, i.e. alloyed and unalloyed steels, cast iron materials, and the most relevant nonferrous materials. At the end of each chapter, the interested reader will find exercises for self-studies. Some of these can be solved using the material presented in the book while others are intended for deepening and further training. Easy examples (with solutions) are found all over the book; they are helpful because they provide information on underlying mechanisms and interdependences that are not obvious at first glance. The information was adapted to new EURO standards and international standards (up to March 2009) as far as these are relevant to Germany. New information is provided, e.g., on new steel standards (constructional steels according to DIN EN 10025), heat-treatable steels according to DIN EN 10025-6 and DIN EN 10083, high-alloy steels according to DIN EN 10088, and filler materials for steel welding according to DIN EN ISO 2560. The systematics of the ''law of cohabitation'' was applied to welding engineering for the first time here. (orig.) [German] Das in vierter Auflage erscheinende Buch widmet sich der Schweissmetallurgie mit ihren Besonderheiten. Die vielfaeltigen Probleme der Eisenwerkstoffe und der nichteisenmetallischen Werkstoffe bei ihrer schweisstechnischen Verarbeitung werden ausfuehrlich dargestellt. Um Korrosionsschaeden an geschweissten Konstruktionen vorzubeugen, wird die Metallurgie aller technisch bedeutsamen Werkstoffe, wie unlegierte und legierte Staehle, Eisen-Gusswerkstoffe, die wichtigsten NE-Metalle, ausfuehrlich besprochen. An den Kapitelenden findet der interessierte Leser Aufgaben, von denen ein

  19. Ceria-based model catalysts: fundamental studies on the importance of the metal-ceria interface in CO oxidation, the water-gas shift, CO2hydrogenation, and methane and alcohol reforming.

    Science.gov (United States)

    Rodriguez, José A; Grinter, David C; Liu, Zongyuan; Palomino, Robert M; Senanayake, Sanjaya D

    2017-04-03

    Model metal/ceria and ceria/metal catalysts have been shown to be excellent systems for studying fundamental phenomena linked to the operation of technical catalysts. In the last fifteen years, many combinations of well-defined systems involving different kinds of metals and ceria have been prepared and characterized using the modern techniques of surface science. So far most of the catalytic studies have been centered on a few reactions: CO oxidation, the hydrogenation of CO 2 , and the production of hydrogen through the water-gas shift reaction and the reforming of methane or alcohols. Using model catalysts it has been possible to examine in detail correlations between the structural, electronic and catalytic properties of ceria-metal interfaces. In situ techniques (X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, infrared spectroscopy, scanning tunneling microscopy) have been combined to study the morphological changes under reaction conditions and investigate the evolution of active phases involved in the cleavage of C-O, C-H and C-C bonds. Several studies with model ceria catalysts have shown the importance of strong metal-support interactions. In general, a substantial body of knowledge has been acquired and concepts have been developed for a more rational approach to the design of novel technical catalysts containing ceria.

  20. Particulate matter emissions, and metals and toxic elements in airborne particulates emitted from biomass combustion: The importance of biomass type and combustion conditions.

    Science.gov (United States)

    Zosima, Angela T; Tsakanika, Lamprini-Areti V; Ochsenkühn-Petropoulou, Maria Th

    2017-05-12

    The aim of this study was to investigate the impact of biomass combustion with respect to burning conditions and fuel types on particulate matter emissions (PM 10 ) and their metals as well as toxic elements content. For this purpose, different lab scale burning conditions were tested (20 and 13% O 2 in the exhaust gas which simulate an incomplete and complete combustion respectively). Furthermore, two pellet stoves (8.5 and 10 kW) and one open fireplace were also tested. In all cases, 8 fuel types of biomass produced in Greece were used. Average PM 10 emissions ranged at laboratory-scale combustions from about 65 to 170 mg/m 3 with flow oxygen at 13% in the exhaust gas and from 85 to 220 mg/m 3 at 20% O 2 . At pellet stoves the emissions were found lower (35 -85 mg/m 3 ) than the open fireplace (105-195 mg/m 3 ). The maximum permitted particle emission limit is 150 mg/m 3 . Metals on the PM 10 filters were determined by several spectrometric techniques after appropriate digestion or acid leaching of the filters, and the results obtained by these two methods were compared. The concentration of PM 10 as well as the total concentration of the metals on the filters after the digestion procedure appeared higher at laboratory-scale combustions with flow oxygen at 20% in the exhaust gas and even higher at fireplace in comparison to laboratory-scale combustions with 13% O 2 and pellet stoves. Modern combustion appliances and appropriate types of biomass emit lower PM 10 emissions and lower concentration of metals than the traditional devices where incomplete combustion conditions are observed. Finally, a comparison with other studies was conducted resulting in similar results.

  1. Effects of alloying element and metallurgical structure on semiconducting characteristics of oxide film of zirconium alloy

    International Nuclear Information System (INIS)

    Inagaki, Masahisa; Kanno, Masayosi; Maki, Hideo.

    1991-01-01

    Semiconducting characteristics of oxide films formed on pure Zr, Zr-Sn binary alloy and Zr-Sn-X (X: Fe, Ni or Cr) ternary alloys were evaluated by photo-electrochemical method, in order to make clear the effects of alloying elements on oxidation mechanism of Zr alloy in BWR environment. Oxide films of the alloys showed the characteristics of n-type semiconductor. Maximum photocurrent (I max) was generated by an illumination of monochromatic light with the energy of 5 ∼ 6 eV, i.e. the band gap energy of the Zr alloy oxide was 5 ∼ 6 eV. This value is lower by 2 ∼ 3 eV than the theoretical band gap energy (8 eV) of stoichiometric ZrO 2 . These facts suggest that the generation of I max was resulted from an excitation of electrons trapped with anion vacancies (oxygen vacancies) of non-stoichiometric ZrO 2-x . Therefore, the value of I max is considered to be proportional to the density of anion vacancy. High corrosion resistant alloys showed lower value of I max. The changes of I max, due to change of chemical composition of alloys and due to the change of metallurgical structure, was able to be explained by the valence theory of oxide semiconductor, i.e. the decrease of 1 max was considered to be resulted from the decrease of anion vacancies due to the substitution of divalent cations (Ni 2+ ) and trivalent cations (Fe 3+ , Cr 3+ ) at Zr 4+ cation sites. From these results, it was concluded that oxidation rate of Zr alloy depended on the density of oxygen vacancies in oxide film. (author)

  2. Long-range electron transfer over graphene-based catalyst for high-performing oxygen reduction reactions: importance of size, N-doping, and metallic impurities.

    Science.gov (United States)

    Choi, Chang Hyuck; Lim, Hyung-Kyu; Chung, Min Wook; Park, Jong Cheol; Shin, Hyeyoung; Kim, Hyungjun; Woo, Seong Ihl

    2014-06-25

    N-doped carbon materials are considered as next-generation oxygen reduction reaction (ORR) catalysts for fuel cells due to their prolonged stability and low cost. However, the underlying mechanism of these catalysts has been only insufficiently identified, preventing the rational design of high-performing catalysts. Here, we show that the first electron is transferred into O2 molecules at the outer Helmholtz plane (ET-OHP) over a long range. This is in sharp contrast to the conventional belief that O2 adsorption must precede the ET step and thus that the active site must possess as good an O2 binding character as that which occurs on metallic catalysts. Based on the ET-OHP mechanism, the location of the electrode potential dominantly characterizes the ORR activity. Accordingly, we demonstrate that the electrode potential can be elevated by reducing the graphene size and/or including metal impurities, thereby enhancing the ORR activity, which can be transferred into single-cell operations with superior stability.

  3. Rheological Behaviour of a Bitumen Modified with Metal Oxides Obtained by Regeneration Processes

    Directory of Open Access Journals (Sweden)

    Tullio Giuffrè

    2018-02-01

    Full Text Available Nowadays, one important challenge is to demonstrate an innovative and integrated approach for the sustainable construction of roads considering the whole life cycle of the infrastructure. Road pavements with multiple asphalt layers generally undergo prolonged environmental exposure and the alternation between solar irradiation and low temperatures. As a result, relaxation or progressive removal of the material with a negative impact on the resistance to plastic deformation occur, also leading to the formation of slits and to dimensional variations, which are commonly defined as thermal cracking. This suggests the use of suitable bitumen modifiers. For these, important parameters are the optimal mixing time and mixing temperature, in order to reduce problems related to the stability of the bitumen. Therefore, the behaviour, upon changing the temperature, of bituminous mixtures containing (as fillers a series of metal oxides coming, as secondary products, from spent acid solutions regeneration processes, was investigated. This is intended in order to recover and reuse those otherwise dangerous wastes coming from several industrial (especially, metallurgical processes. The study was aimed at evaluating the properties of bituminous blends by performing rheological tests under dynamic shear regime. More specifically, five different bitumen matrices were prepared (70/100 bitumen and blends with metal oxides and/or SBS copolymer. Results showed that the addition of iron oxides leads to an increase of the softening point and the complex modulus. The increase is even more emphasized when SBS is added to the blend.

  4. Metallurgical response of an AISI 4140 steel to different plasma nitriding gas mixtures

    Directory of Open Access Journals (Sweden)

    Adão Felipe Oliveira Skonieski

    2013-01-01

    Full Text Available Plasma nitriding is a surface modification process that uses glow discharge to diffuse nitrogen atoms into the metallic matrix of different materials. Among the many possible parameters of the process, the gas mixture composition plays an important role, as it impacts directly the formed layer's microstructure. In this work an AISI 4140 steel was plasma nitrided under five different gas compositions. The plasma nitriding samples were characterized using optical and scanning electron microscopy, microhardness test, X-ray diffraction and GDOES. The results showed that there are significant microstructural and morphological differences on the formed layers depending on the quantity of nitrogen and methane added to the plasma nitriding atmosphere. Thicknesses of 10, 5 and 2.5 µm were obtained when the nitrogen content of the gas mixtures were varied. The possibility to obtain a compound layer formed mainly by γ'-Fe4N nitrides was also shown. For all studied plasma nitriding conditions, the presence of a compound layer was recognized as being the responsible to hinder the decarburization on the steel surface. The highest value of surface hardness - 1277HV - were measured in the sample which were nitrided with 3vol.% of CH4.

  5. Tracing sediment sources in the Williams River catchment using caesium-137 and heavy metals: towards an assessment of the relative importance of surface erosion and gully erosion

    International Nuclear Information System (INIS)

    Krause, A.K.; Kalma, J.D.; Loughran, R.J.

    1999-01-01

    Recent sediment sourcing in the 1175km 2 Williams River catchment near Newcastle, NSW, has involved the use of caesium-137 ( 137 Cs) and heavy metals to identify zones of erosion and estimate erosion rates. Sediment sources to the Williams River include sheet erosion from forested and grazed lands, stream channels (especially banks), gullies and roads. The fallout environmental radioisotope 137 Cs was used to assess the erosion status of five vegetated slopes using soil sampling along transects. The net loss or gain of 137 Cs at each sampling point was compared with the 137 Cs level at a reference site at the slope crest. Net soil loss at each point was calculated from an Australian regression model relating net soil loss from runoff-erosion plots to 137 Cs deficit in soils (n=34; r=0.84). Net soil gain was calculated using the regression model in reverse mode. A weighted net soil loss (or gain) was then calculated for each slope transect. Results showed low net soil loss, ranging from zero to 0.64 t ha -1 yr 1 , suggesting that slopes were not major contributors of sediment to the Williams River. A small sub-catchment south of Wirragulla Hill, typical of the lower Williams region, was selected for more detailed tracing of sediment sources. The catchment contains gullies, sheet-erosion exposed sub-soil, grassland and one unsealed road. Heavy metals and 137 Cs have been used to fingerprint the sources, and these measurements will be compared with suspended sediment collected from drainage water in the creek. Only preliminary results have been obtained for this component of the study. The paper will assess these two approaches for the identification of sediment sources and discuss practical applications in water resources management

  6. Pair natural orbital and canonical coupled cluster reaction enthalpies involving light to heavy alkali and alkaline earth metals: the importance of sub-valence correlation

    KAUST Repository

    Minenkov, Yury

    2017-03-07

    In this work, we tested canonical and domain based pair natural orbital coupled cluster methods (CCSD(T) and DLPNO-CCSD(T), respectively) for a set of 32 ligand exchange and association/dissociation reaction enthalpies involving ionic complexes of Li, Be, Na, Mg, Ca, Sr, Ba and Pb(ii). Two strategies were investigated: in the former, only valence electrons were included in the correlation treatment, giving rise to the computationally very efficient FC (frozen core) approach; in the latter, all non-ECP electrons were included in the correlation treatment, giving rise to the AE (all electron) approach. Apart from reactions involving Li and Be, the FC approach resulted in non-homogeneous performance. The FC approach leads to very small errors (<2 kcal mol-1) for some reactions of Na, Mg, Ca, Sr, Ba and Pb, while for a few reactions of Ca and Ba deviations up to 40 kcal mol-1 have been obtained. Large errors are both due to artificial mixing of the core (sub-valence) orbitals of metals and the valence orbitals of oxygen and halogens in the molecular orbitals treated as core, and due to neglecting core-core and core-valence correlation effects. These large errors are reduced to a few kcal mol-1 if the AE approach is used or the sub-valence orbitals of metals are included in the correlation treatment. On the technical side, the CCSD(T) and DLPNO-CCSD(T) results differ by a fraction of kcal mol-1, indicating the latter method as the perfect choice when the CPU efficiency is essential. For completely black-box applications, as requested in catalysis or thermochemical calculations, we recommend the DLPNO-CCSD(T) method with all electrons that are not covered by effective core potentials included in the correlation treatment and correlation-consistent polarized core valence basis sets of cc-pwCVQZ(-PP) quality.

  7. The history of decisions on creation of nuclear and metallurgical complex on the basis of the Kola nuclear power plant

    Directory of Open Access Journals (Sweden)

    Kudrin B. I.

    2017-02-01

    Full Text Available Some reasons for the choice of directions for using electric and thermal energy of the Kola nuclear power plant located beyond the Arctic Circle have been presented. The regions of the country and their large-scale industrial productions based on metallurgical enterprises have been indicated; the electrical supply of these enterprises is implemented from the Kola NPP. The results of research of energy inputs for the production of a ton of steel and cast iron have been presented. It has been determined that the main direction of technological modernization in the steel industry is avoiding the use of organic fuels (particularly in coke-blast furnace production as the most energy-intensive and its replacement with the technology of direct reduction of iron with hydrogen. As an alternative energy source for organic fuels the creation of a fuel-free nuclear-metallurgical electrified complex has been proposed. The principal scheme of the fuel-free nuclear-metallurgical electrified complex has been described, here the main novelty has a reducing gases preparation block giving the potential ability for creating waste-free process. It has been noted that this technology requires using high temperatures and solving technical problems related to heat resistance of constructions. Some examples of world research on the implementation of similar projects have been presented. It has been determined that the use of new technology will cause the need for optimization of power consumption structure due to the redistribution of capacity and electrical consumption between productions. The introduction of new technologies requires solving a number of problems on electric power supply and electrical equipment designing. It has been observed that on the Kola NPP large-scale reconstruction was carried out during the working period, it helped to increase its project capacity and extend the operation life. Nowadays the region has excess installed capacity that can be

  8. Electrical discharge in gases: a technique for detecting metal anomalies

    International Nuclear Information System (INIS)

    Lord, D.E.

    1979-01-01

    Optical ionization effects in gases appear to be very sensitive indicators of nonuniformities caused by contamination, deformation, and other factors affecting a metal surface. These optical effects are influenced by surface electron emission, which is influenced in turn by the chemical, metallurgical, and mechanical condition of the metal surface. Based on these effects, a general technique for inspection of critical parts that is fast, inexpensive, nondestructive, and not limited by size or geometry is presented. Ionization effects that reveal nonuniformities and were recorded with standard photographic equipment are shown

  9. Synergistic Separation Behavior of Boron in Metallurgical Grade Silicon Using a Combined Slagging and Gas Blowing Refining Technique

    Science.gov (United States)

    Wu, Jijun; Zhou, Yeqiang; Ma, Wenhui; Xu, Min; Yang, Bin

    2017-02-01

    A combined slagging and gas blowing refining technique for boron removal from metallurgical grade silicon using the CaO-SiO2-CaCl2 slag and the mixed Ar-O2-H2O gas is investigated. The oxygen gas blowing in combination with water vapor shows a wonderful removal efficiency of boron compared with the single oxygen or the single water vapor blowing. It is analyzed from the thermodynamics that a synergistic separation behavior of boron is resulted from CaCl2 and O2. Boron is removed and reduced from 22 to 0.75 ppmw with a removal efficiency of 96.6 pct.

  10. Heavy metal jako subkultura

    OpenAIRE

    KOUTNÁ, Daniela

    2016-01-01

    This bachelor thesis deals with heavy metal subculture. Its aim is to introduce the most important branches and to show broadness of heavy metal. This bachelor thesis describes development and history, briefly shows Czech heavy metal history alongside with the biggest and most popular Czech heavy metal festivals. It shows the most dressing concerns of society against this style.

  11. Importance of exposure dynamics of metal-based nano-ZnO, -Cu and -Pb governing the metabolic potential of soil bacterial communities.

    Science.gov (United States)

    Zhai, Yujia; Hunting, Ellard R; Wouterse, Marja; Peijnenburg, Willie J G M; Vijver, Martina G

    2017-11-01

    Metal-based engineered nanomaterials (ENMs) are known to affect bacterial processes and metabolic activities. While testing their negative effects on biological components, studies traditionally rely on initial exposure concentrations and thereby do not take into consideration the dynamic behavior of ENMs that ultimately determines exposure and toxicity (e.g. ion release). Moreover, functional responses of soil microbial communities to ENMs exposure can be caused by both the particulate forms and the ionic forms, yet their relative contributions remain poorly understood. Therefore, we investigated the dynamic changes of exposure concentrations of three different types of ENMs (nano-ZnO, -Cu and -Pb) and submicron particles (SMPs) in relation to their impact on the capacity of soil bacterial communities to utilize carbon substrates. The different ENMs were chosen to differ in dissolution potential. The dynamic exposures of ENMs were considered using a time weighted average (TWA) approach. The joint toxicity of the particulate forms and the ionic forms of ENMs was evaluated using a response addition model. Our results showed that the effect concentrations of spherical nano-ZnO, -Cu and SMPs, and Pb-based perovskites expressed as TWA were lower than expressed as initial concentrations. Both particulate forms and ionic forms of spherical 18nm, 43nm nano-ZnO and 50nm, 100nm nano-Cu contribute to the overall response at the EC 50 levels. The particulate forms for 150nm, 200nm and 900nm ZnO SMPs and rod-shaped 78nm nano-Cu mainly affected the soil microbial metabolic potential, while the Cu ions released from spherical 25nm nano-Cu, 500nm Cu SMPs and Pb ions released from perovskites mainly described the effects to bacterial communities. Our results indicate that the dynamic exposure of ENMs and relative contributions of particles and ions require consideration in order to pursue a naturally realistic assessment of environmental risks of metal-based ENMs. Copyright

  12. The importance of evaluating the real metal concentration in nanoparticles post-synthesis for their applications: A case-study using silver nanoparticles.

    Science.gov (United States)

    Galazzi, Rodrigo Moretto; Santos, Elias de Barros; Caurin, Tatiana; Pessôa, Gustavo de Souza; Mazali, Italo Odone; Arruda, Marco Auréli Zezzio

    2016-01-01

    To determine whether the effect observed in a study is related to the nanoparticle only or to their synergic effect with the "free" metal ions, the real concentration of silver (104±8 and 100±2 mg L(-1)) after AgNP synthesis is obtained through ICP-MS and ICP OES in the solution after the AgNP synthesis and in different fractions after centrifugation (at 8100 g for 40 min). From the resuspension of the AgNP contained in the solution (AgNP-total) after synthesis (AgNP-res), concentrations of 49±3 and 51±3 mg L(-1) are found and concentrations of 50±7 and 47±2 mg L(-1) in the supernatant (Ag-sup) are found using ICP-MS and ICP OES respectively. The characterization of AgNP-total, AgNP-res and Ag-sup is performed by HRTEM and UV-vis, corroborating the results in terms of Ag determination, and indicates that half of the total silver concentration is in the AgNP form and that the other half is in the "free" silver form. The results of the stability test of the NPs indicate a 7% decrease in Ag as NP three months after its synthesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Metallurgical characterization, galvanic corrosion, and ionic release of orthodontic brackets coupled with Ni-Ti archwires.

    Science.gov (United States)

    Darabara, Myrsini S; Bourithis, Lefteris I; Zinelis, Spiros; Papadimitriou, George D

    2007-04-01

    In orthodontics, a combination of metallic alloys is placed into the oral cavity during medical treatment and thus the corrosion resistance and ionic release of these appliances is of vital importance. The aim of this study is to investigate the elemental composition, microstructure, hardness, corrosion properties, and ionic release of commercially available orthodontic brackets and Copper Ni-Ti archwires. Following the assessment of the elemental composition of the orthodontic wire (Copper Ni-Ti) and the six different brackets (Micro Loc, Equilibrium, OptiMESH(XRT), Gemini, Orthos2, and Rematitan), cyclic polarization curves were obtained for each material to estimate the susceptibility of each alloy to pitting corrosion in 1M lactic acid. Galvanic corrosion between the orthodontic wire and each bracket took place in 1M lactic acid for 28 days at 37 degrees C and then the ionic concentration of Nickel and Chromium was studied. The orthodontic wire is made up from a Ni-Ti alloy with copper additions, while the orthodontic brackets are manufactured by different stainless steel grades or titanium alloys. All tested wires and brackets with the exception of Gemini are not susceptible to pitting corrosion. In galvanic corrosion, following exposure for 28 days, the lowest potential difference (approximately 250 mV) appears for the orthodontic wire Copper Ni-Ti and the bracket made up from pure titanium (Rematitan) or from the stainless steel AISI 316 grade (Micro Loc). Following completion of the galvanic corrosion experiments, measurable quantities of chromium and nickel ions were found in the residual lactic acid solution. (c) 2006 Wiley Periodicals, Inc.

  14. MODELLING OF BICOLOR PYROMETER WITH LIGHT-GUIDING TRACT FOR METALLURGICAL FURNACES

    OpenAIRE

    E. I. Marukovich; L. F. Zhukov; Ju. N. Kochkin; A. A. Romanenko; Ju. L. Stanulenis

    2010-01-01

    Theoretical explanation of creation of two-color pyrometer with light-guiding transmission is given. The example of practical application of such type of pyrometer for the molten metal temperature control in laboratory furnace is given.

  15. MODELLING OF BICOLOR PYROMETER WITH LIGHT-GUIDING TRACT FOR METALLURGICAL FURNACES

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2010-01-01

    Full Text Available Theoretical explanation of creation of two-color pyrometer with light-guiding transmission is given. The example of practical application of such type of pyrometer for the molten metal temperature control in laboratory furnace is given.

  16. Cumulative internal dose of natural uranium in chemical industry workers and metal; Dosis interna acumulada de uranio natural en trabajadores de la industria quimica y del metal

    Energy Technology Data Exchange (ETDEWEB)

    Capelo, R.; Garcia, M. A.; Jara, R.; Galisteo, R.; Diaz-Santos, M.; Caballero, F. J.; Pereira, A.; Rosa, J. de la; Garcia, T.; Gomez-Ariza, J. L.; Alguacil, J.

    2011-07-01

    Natural uranium is a slightly radioactive element that decays slowly by emitting an alpha particle. If absorbed by the human body can cause health effects. For people who perform their work in the chemical/metallurgical or mining it would be the main source of exposure, while for the rest of the population's main source of exposure is usually the diet. The aim of this study was to measure the cumulative dose of uranium in chemical industry workers/metal.

  17. Assessing market structures in resource markets. An empirical analysis of the market for metallurgical coal using various equilibrium models

    Energy Technology Data Exchange (ETDEWEB)

    Lorenczik, Stefan; Panke, Timo [Koeln Univ. (Germany). Inst. of Energy Economics

    2015-05-15

    The prevalent market structures found in many resource markets consist of a high concentration on the supply side and a low demand elasticity. Market results are therefore frequently assumed to be an outcome of strategic interaction between producers. Common models to investigate the market outcomes and underlying market structures are games representing competitive markets, strategic Cournot competition and Stackelberg structures taking into account a dominant player acting first followed by one or more followers. Besides analysing a previously neglected scenario of the latter kind, we add to the literature by expanding the application of mathematical models by applying an Equilibrium Problem with Equilibrium Constraints (EPEC), which is used to model multi-leader-follower games, to a spatial market. We apply our model by investigating the prevalent market setting in the international market for metallurgical coal between 2008 and 2010, whose market structure provides arguments for a wide variety of market structures. Using different statistical measures and comparing model with actual market outcomes, we find that two previously neglected settings perform best: First, a setting in which the four largest metallurgical coal exporting firms compete against each other as Stackelberg leaders, while the remainders act as Cournot followers. Second, a setting with BHPB acting as sole Stackelberg leader.

  18. Assessing market structures in resource markets. An empirical analysis of the market for metallurgical coal using various equilibrium models

    International Nuclear Information System (INIS)

    Lorenczik, Stefan; Panke, Timo

    2015-01-01

    The prevalent market structures found in many resource markets consist of a high concentration on the supply side and a low demand elasticity. Market results are therefore frequently assumed to be an outcome of strategic interaction between producers. Common models to investigate the market outcomes and underlying market structures are games representing competitive markets, strategic Cournot competition and Stackelberg structures taking into account a dominant player acting first followed by one or more followers. Besides analysing a previously neglected scenario of the latter kind, we add to the literature by expanding the application of mathematical models by applying an Equilibrium Problem with Equilibrium Constraints (EPEC), which is used to model multi-leader-follower games, to a spatial market. We apply our model by investigating the prevalent market setting in the international market for metallurgical coal between 2008 and 2010, whose market structure provides arguments for a wide variety of market structures. Using different statistical measures and comparing model with actual market outcomes, we find that two previously neglected settings perform best: First, a setting in which the four largest metallurgical coal exporting firms compete against each other as Stackelberg leaders, while the remainders act as Cournot followers. Second, a setting with BHPB acting as sole Stackelberg leader.

  19. Application of Six Sigma Using DMAIC Methodology in the Process of Product Quality Control in Metallurgical Operation

    Directory of Open Access Journals (Sweden)

    Girmanová Lenka

    2017-12-01

    Full Text Available The Six Sigma DMAIC can be considered a guide for problem solving and product or process improvement. The majority of companies start to implement Six Sigma using the DMAIC methodology. The paper deals with application of Six Sigma using the DMAIC methodology in the process of product quality control. The case study is oriented on the field of metallurgical operations. The goal of the Six Sigma project was to ensure the required metallurgic product quality and to avoid an increase in internal costs associated with poor product quality. In this case study, a variety of tools and techniques like flow chart, histogram, Pareto diagram, analysis of FMEA (Failure Mode and Effect Analysis data, cause and effect diagram, logical analysis was used. The Sigma level has improved by approximately 13%. The achieved improvements have helped to reduce the quantity of defective products and the processing costs (technology for re-adjusting. Benefits resulting from the DMAIC implementation can be divided into three levels: the qualitative, economic and safety level.

  20. Effect of Laser Beam Alloying Strategies on the Metallurgical and Mechanical Properties of Hot Forming Tool Steels

    Science.gov (United States)

    Hofmann, Konstantin; Neubauer, Franziska; Holzer, Matthias; Mann, Vincent; Hugger, Florian; Roth, Stephan; Schmidt, Michael

    In terms of increasing lightweight designs of car body parts, the machining of high strength steels in hot stamping processes becomes of particular interest. Due to high process forces at hot stamping, the surface of such tools in the area of maximal stress is subject wear, which necessitate some local increase of microhardness to enhance the mechanical performance. Especially laser beam alloying using filler wire and beam oscillation is some suitable method to modify the mechanical properties of tool surfaces to emcompass some continuous martensitic structure, featuring a certain microhardness. Nevertheless the thermal energy input during laser beam alloying induces tempering in the heat affected zone and reduces the hardness. This paper discusses the influence of alloying strategies on the thermal energy input and the resulting metallurgical structure of modified tool surfaces. Also the cooling behavior of alloyed lines for different energy inputs per unit length is of interest. Therefore, the metallurgical microstructure is analyzed regarding microhardness as well as formation of carbides. Furthermore, a numerical thermal simulation is developed to investigate the temperature profile in the heat affected zone of the specimen. These investigations permit the control of the spatiotemporal energy input to avoid tempering of the microstructure.

  1. Considerations about recovery of critical metals using bio-metallurgy

    Directory of Open Access Journals (Sweden)

    Gherghe Săndica Liliana

    2017-01-01

    Full Text Available The increased requirement of critical metals due to green technologies needs, together with the geopolitical environment to ensure these metals, has entailed decisive measures to avoid current supply insecurities in each country. These metals are essential to the products and services made and used daily, and contribute to sustaining and growing the economy. Thus, sustainable approaches from technological, environmental, economic and social point of view are needed to recover these metals from different resources. By using resources more efficiently, innovating in the concept of circular economy, it can be assure re-using, re-manufacturing or recycling of valuable materials. In this paper are presented some considerations related to using the waste dumps as potential resources to obtain critical metals by bio-metallurgical processes.

  2. Leading research on next generation metal production technology; Jisedai kinzoku shigen seisan gijutsu no sendo kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The energy saving environment-friendly technology for low- grade difficult-to-process ores was researched focusing attention on the hydro-metallurgical process of non-ferrous metals. This research aims at development of both effective leaching system of metals, and separation/crystallization system recognizing the property difference between metal ions in solution. The leaching system allows the inexpensive molecular level control of electron transfer, mass transfer of metal ions and stabilization of leached metal ions in a solid/liquid interface. The system thus allows selective leaching of metals from various resources such as difficult- to-leach sulfide minerals to prepare concentrated solutions. The separation system can obtain high-purity solutions including each metal ion by advanced separation/concentration technology from the solutions. The crystallization technology (including electrolysis) is developed for preparing target metal materials by molecular level control of nucleation, particle growth, thin film formation and bulky metal formation processes. Overall energy consumption is reduced to 1/3 of that of the pyro-metallurgical method, aiming at zero emission. 15 refs., 14 figs., 11 tabs.

  3. Importance measures

    International Nuclear Information System (INIS)

    Gomez Cobo, A.

    1997-01-01

    The presentation discusses the following: general concepts of importance measures; example fault tree, used to illustrate importance measures; Birnbaum's structural importance; criticality importance; Fussel-Vesely importance; upgrading function; risk achievement worth; risk reduction worth

  4. Environmental impact of the minero-metallurgic industry on the marine ecosystem in Moa, Cuba

    International Nuclear Information System (INIS)

    Martinez Canals, M.; Pedro Garcia, L.

    1999-01-01

    One of the biggest nickel mineral deposits of the world is located in Moa; therefore two plants are installed for the extraction of this metal in the region, and another is in its construction phase. During the technological processes, residuals that contain great quantity of metallic elements, and high acidity level are discharged into the environment. The objectives of this research were to establish the levels of pollution of eleven metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in the superficial bottom sediments, sea water and organisms of the marine aquatorium (green and white sea urchins, blue crabs, oysters and mangrove leaves). The dynamics of pollution in superficial sediments was also determined in the course of a 9-year study. As complementary analyses, pH and salinity were determined for the supradjacent water to the marine bottom, as well as the content of organic carbon, and granulometry of the sediment

  5. Corrosion resistance of Ni-Cr-Mo alloys. Chemical composition and metallurgical condition's effects

    International Nuclear Information System (INIS)

    Zadorozne, N.S.; Rebak, Raul B.

    2009-01-01

    P, may form if Ni-Cr-Mo alloys are exposed for tens of hours in the range of 600 C degrees to 1100 C degrees. These phases could have a detrimental effect upon corrosion resistance and cause a loss of mechanical ductility. The precipitation of TCP phases starts at grain boundaries and for long aging times it progresses to twins boundaries and then the grain bodies. TCP phases are rich in Mo and Cr. Zones in the matrix adjacent to the TCP precipitates may be depleted of Cr and Mo, and the alloy becomes sensitized.The aim of the present work was to compare the general corrosion rate and the crevice corrosion susceptibility of alloys C-22, C-22HS and HYBRID-BC1 in different metallurgical conditions when exposed to hot chloride solutions. The effects of the alloy composition and different heat treatments were assessed. (author)

  6. Materials design considerations involved in the fabrication of implantable bionics by metallization of ceramic substrates.

    Science.gov (United States)

    Patel, Sunil; Guenther, Thomas; Dodds, Christopher W D; Kolke, Sergej; Privat, Karen L; Matteucci, Paul B; Suaning, Gregg J

    2013-01-01

    The Pt metallization of co-fired Al2O3/SiO2 substrates containing Pt feedthroughs was shown to be a suitable means to construct implantable bionics. The use of forge welding to join an electrode to such a metallized feedthrough was demonstrated and subsequently evaluated through the use of metallography and electron microscopy. Metallurgical phenomena involved in forge welding relevant to the fabrication of all types of biomedical implants are discussed within this paper. The affect of thermal profiles used in brazing or welding to build implantable devices from metal components is analysed and the case for considered selection of alloys in implant design is put forward.

  7. New metallurgical feasibilities in improvement of steel and alloy corrosion resistance

    International Nuclear Information System (INIS)

    Khasin, G.A.; Pokrovskij, A.B.; Krylov, S.M.; Leonovich, B.I.; Tomilov, V.I.

    1981-01-01

    New methods of the improvement of steel and alloy corrosion resistance are described. Some versions of technology of especially corrosion resistant steels melting in arc furnace with low carbon content are developed. One of such methods provides the complete decarburization of iron-nickel melt by oxygen-air mixture, the transition to the reduction period without the skimming of oxidation slag, ferrochromium melting at the expense of excess heat and the final reduction and refining of metal by inert gas blowing in the ladle. The 03Kh18N11, 03Kh18N12, 03Kh21N21M4GB, 03Kh17N14M3 and other steels are melted using this technology. Lately the melting technology of corrosion resistant and other alloyed steels and alloys with program thermo-time treatment of melts in arc and open induction furnaces is introduced. The method of phase equilibria calculation, which permits to estimate qualitatively and quantitatively the phases, formed in liquid metal during its solidification, and in solid metal, depending on temperature and composition of metal, is developed. Using the casting method, the production of corrosion resistant compositions with titanium carbides, is realized. Heat treatment and deformation methods of corrosion resistant steels and alloys are also discussed [ru

  8. Metallurgical evaluation of laser additive manufactured Ti6Al4V components

    CSIR Research Space (South Africa)

    Mutombo, K

    2013-10-01

    Full Text Available -10. 2. D.E. Cooper, M. Stanford, K.A.Kibble and G.J. Gibbons, “Additive manufacturing for product improvement at Red Bull Technology, “Materials and Design, 2012 (41), 226-230. 3. C. Sanz and V. Garcia Navas, “Structural integrity of direct metal laser...

  9. Effect of groove design on mechanical and metallurgical properties of quenched and tempered low alloy abrasion resistant steel welded joints

    International Nuclear Information System (INIS)

    Sharma, Varun; Shahi, A.S.

    2014-01-01

    Highlights: • Effect of weld groove design on Q and T steel welded joints is investigated. • Groove design influences heat dissipation characteristics of welded joints. • Double-V groove joint possesses maximum yield strength and UTS. • C-groove joint possesses highest impact energy, both at room temperature and 0 °C. • A wide variation in microhardness exists across different zone of the weldments. - Abstract: Experimental investigations were carried out to study the influence of three different groove designs on mechanical and metallurgical properties of 15 mm thick Q and T (quenched and tempered) steel welded joints. Welding heat input variation corresponding to each joint configuration was kept to a minimal such that the objective of investigating, exclusively, the effect of varied weld volume on the mechanical and metallurgical performance of these joints could be accomplished. Mechanical performance of these joints was evaluated by subjecting them to transverse tensile testing, and Charpy V-notch impact testing of the weld zones at room temperature and 0 °C. The results of this study reveal that among all types of groove formations used for welding, double-V groove joint possessed maximum YS (yield strength) and UTS (ultimate tensile strength), besides maximum strength ratio (YS/UTS) that was followed by U-groove joint and C-groove joint, respectively. However, weld zone tested individually, for the cover as well as the root pass of the C-groove joint possessed highest CVN (Charpy V-notch) values, both at room temperature and 0 °C. Extensive microhardness studies of these weldments showed a wide variation in the microhardness values of the weld zone and the HAZ (heat affected zone). It was concluded that each groove formation/design exerted a significant influence on the heat dissipation characteristics of these joints, which is evident from different morphological features as revealed through optical microscopy. Scanning electron microscopic

  10. Occupational exposure to PCDDs, PCDFs, and PCBs of metallurgical workers in some industrial plants of the Brescia area, northern Italy.

    Science.gov (United States)

    Abballe, Annalisa; Barbieri, Pietro Gino; di Domenico, Alessandro; Garattini, Siria; Iacovella, Nicola; Ingelido, Anna Maria; Marra, Valentina; Miniero, Roberto; Valentini, Silvia; De Felip, Elena

    2013-01-01

    The study was carried out in order to respond to public concern on the occupational exposure of metallurgical workers to highly toxic PCDDs, PCDFs, and PCBs in the area of the city of Brescia, northern Italy. The study investigated the effects on the haematic burden of occupational exposures to the aforesaid contaminants in different work environments, attempting to establish causal relationships and providing indications for occupational health preventive measures. Chemical concentrations were measured in blood serum of "professionally exposed" (PE) and "not professionally exposed" (NPE) subjects. NPE subjects included industrial administrative employees, Brescia inhabitants, and remote rural people. The central tendency indexes of contaminant cumulative concentrations were higher in PE than in NPE samples (for the mean values: PCDDs+PCDFs, 22.9 vs. 19.5 pgWHO-TEQ(1997)/g lb; DL-PCBs, 26.0 vs. 23.6 pgWHO-TEQ(1997)/g lb; PCDDs+PCDFs+DL-PCBs (TEQ(TOT)), 48.9 vs. 43.1 pgWHO-TEQ(1997)/g lb; Σ(6)[NDL-PCBs], 427 vs. 401 ng g(-1)lb); however, no statistical differences were detected at P=0.05. A significant difference for PCDDs+PCDFs and TEQ(TOT) was observed as the NPE data were progressively reduced to those of the remote rural people. The existence of a differential occupational exposure due to different environments was detected by applying the factor analysis to congener-specific data (analytical profiles). Findings indicate that metallurgical workers may be exposed to PCDD, PCDF, and PCB more than the general population, in particular due to non-negligible contributions to exposure from workplace ambient air. Findings also suggest that an improvement of preventive measures may be required to avoid chemical overexposure in certain metallurgical workplaces. To identify exposure groups, the DL- and NDL-PCB analytical profiles seemed to be more sensitive to environmental exposure sources/pathways than those of PCDDs and PCDFs. Copyright © 2012 Elsevier Ltd. All

  11. Application of liquid metals for the extraction of solid metals

    International Nuclear Information System (INIS)

    Borgstedt, H.U.

    1996-01-01

    Liquid metals dissolve several solid metals in considerable amounts at moderate temperatures. The dissolution processes may be based upon simple physical solubility, formation of intermetallic phases. Even chemical reactions are often observed in which non-metallic elements might be involved. Thus, the capacity to dissolve metals and chemical properties of the liquid metals play a role in these processes. Besides the solubility also chemical properties and thermochemical data are of importance. The dissolution of metals in liquid metals can be applied to separate the solutes from other metals or non-metallic phases. Relatively noble metals can be chemically reduced by the liquid phases. Such solution processes can be applied in the extractive metallurgy, for instance to extract metals from metallic waste. The recycling of metals is of high economical and ecological importance. Examples of possible processes are discussed. (author)

  12. The interaction of hydrogen with metal alloys

    Science.gov (United States)

    Danford, M. D.; Montano, J. W.

    1991-01-01

    Hydrogen diffusion coefficients were measured for several alloys, and these were determined to be about the same at 25 C for all alloys investigated. The relation of structure, both metallurgical and crystallographic, to the observed hydrogen distribution on charging was investigated, as well as the role of hydride formation in the hydrogen resistance of metal alloys. An attempt was made to correlate the structures and compositions of metal alloys as well as other parameters with the ratios of their notched tensile strengths in hydrogen to that in helium, R(H2/He), which are believed to represent a measure of their hydrogen resistance. Evidence supports the belief that hydrogen permeability and hydrogen resistance are increased by smaller grain sizes for a given alloy composition.

  13. Recent advances and future perspectives of nanosized zero- valent iron for extraction of heavy elements from metallurgical sludges

    Science.gov (United States)

    Mikhailov, I. Yu; Levina, V. V.; Kolesnikov, E. A.; Chuprunov, K. O.; Gusev, A. A.; Godymchuk, A. Yu; Kuznetsov, D. V.

    2016-01-01

    Advanced oxidation processes with nanosized zero-valent iron have presented great potential in wastewater treatment technology and now experience both increasing popularity and reliable technical improvements. Besides wastewater treatment, there is another promising application for an emerging technology of iron nanoparticles - as Fenton-like catalyst for extraction of valuable elements from poor and secondary raw materials such as metallurgical sludges. In present research, we carried out a set of experiments with emphasis on the physicochemical mechanisms and their relationship to the performance. In particular, we examined complex acidic - hydrogen peroxide leaching of zinc from blast furnace sludge with nanosized zero-valent iron as Fenton-like catalyst. Results of the experiments showed promising potential for subsequent application in extraction of heavy and rare-earth elements.

  14. Recent advances and future perspectives of nanosized zero- valent iron for extraction of heavy elements from metallurgical sludges

    International Nuclear Information System (INIS)

    Mikhailov, I Yu; Levina, V V; Kolesnikov, E A; Chuprunov, K O; Gusev, A A; Godymchuk, A Yu; Kuznetsov, D V

    2016-01-01

    Advanced oxidation processes with nanosized zero-valent iron have presented great potential in wastewater treatment technology and now experience both increasing popularity and reliable technical improvements. Besides wastewater treatment, there is another promising application for an emerging technology of iron nanoparticles - as Fenton-like catalyst for extraction of valuable elements from poor and secondary raw materials such as metallurgical sludges. In present research, we carried out a set of experiments with emphasis on the physicochemical mechanisms and their relationship to the performance. In particular, we examined complex acidic - hydrogen peroxide leaching of zinc from blast furnace sludge with nanosized zero-valent iron as Fenton-like catalyst. Results of the experiments showed promising potential for subsequent application in extraction of heavy and rare-earth elements. (paper)

  15. Metallurgical investigation of cracking of the isolation valve downstream piping of regenerative heat exchanger at beaver valley unit 1 station

    International Nuclear Information System (INIS)

    Rao, G.V.

    1998-01-01

    A metallurgical investigation was conducted to establish the mechanism and cause of cracking in the regenerative heat exchanger piping at Beaver Valley Unit 1 PWR station in the USA. The investigation, which was centered on an eight inch long pipe section containing the cracking included surface examinations, metallographic and fractographic examinations, and chemistry evaluations. The results of the examinations showed that there were two types of pipe degradation mechanisms that affected the type 304 stainless schedule 40 piping. These consisted of localized corrosive attack on the OD surface due to the presence of chlorides, sulphates and phosphates, and transgranular stress corrosion cracking in the pipe wall due to the presence of chloride contaminants. The overall results of the investigation showed that the introduction of contaminants from external sources other than pipe insulation was the cause of heat exchanger pipe cracking. (author)

  16. Theoretical and experimental research on the use of expert systems (ES in assessing risks of failure in metallurgical companies

    Directory of Open Access Journals (Sweden)

    E. Iancu

    2013-04-01

    Full Text Available The systems’ engineering has reached an explosive development of intelligent systems technology which solves complex problems based on human expertise accumulated in the past and following the processes of learning and reasoning very similar to those of the biological brain. In this article, the concept of the proposed expert system is the result of interdisciplinary researches (computer science, management, accounting and business administration, etc., which are designed to provide a tool for top management work force of a listed metallurgical company. The inference machine will provide in the end score functions for Altman, Conan Holder model and rating which eventually can be combined into a single model that will forecast the company’s evolution in coming years.

  17. Competitiveness and Economic Security — Priority Problems of the Region’s Metallurgical Comples and Its Leaders in the Conditions Of Instability

    Directory of Open Access Journals (Sweden)

    Andrey Anatolyevich Kozitsyn

    2015-09-01

    Full Text Available The subject-matter of the research is the study of the regional metallurgical complex and its leaders, which account for 55 % of industrial output and more than 57 % of exports of the Sverdlovsk region, in the current terms of economic instability. Supporting the business priorities of improving the competitiveness and economic security of the enterprise is based on the example of "UMMCHolding" — the leader of ferrous metallurgy in the Middle Urals, an active participant in the global and Russian copper market. The modern economic, mathematical, and general scientific methods (comparison study, the ratio of total and private, and others are applied as the research methods. To obtain the study results, the main areas of the holding impacted by the sanctions are analyzed: modernization of production and spare parts provisions of the current imported equipment, correction of the supply chain, searching for new business partners, transformation of the structure and direction of cargo traffic, solving transportation problems, stocks system management and minimization of economic, social and environmental costs. The urgency of solving the problem of company competitiveness and economic security increasing together with its sectoral and regional features in the present conditions is proved as the key conclusion. The high competitiveness of the holding is considered to be one of the factors of its economic security. The main goal of the economic security of the company is its sustainable and maximally effective functioning at the present time and high potential for successful development in the future. The indicators and criteria for the economic security evaluation are studied in detail. The analysis conducted has shown that, in general, the holding has high indicators characterizing its economic security on the basis of high competitiveness. As a negative sign, a lack of the investment growth needed to solve urgent problems is noticed.

  18. A novel application of resin in pulp in the metallurgical industry

    International Nuclear Information System (INIS)

    Fleming, C.A.; Cromberge, G.

    1985-01-01

    The results are presented of several small-scale pilot-plant investigations that demonstrate the feasibility of a resin-in-pulp process for the combined extraction of gold and uranium. Both metals are leached into an aqueous solution as anionic complexes, and, under appropriate conditions, both metal anions can be stabilized in the same solution and extracted from that solution by anion-exchange resins. Three different lead materials containing gold and uranium were tested, and several configurations for leaching and the resin-in-pulp process were examined so that the efficiency of extraction of the process could be demonsrated. The results of the various pilot-plant investigations are discussed with particular emphasis on the deportment of gold and uranium during the leaching extraction, and elution steps

  19. Development of technology for the process of neutralization of pickling solution of metallurgical production

    Directory of Open Access Journals (Sweden)

    Lamzina I.V.

    2016-12-01

    Full Text Available The leading branch of territorial-production complex of Russia - mechanical engineering. Companies of the industry throw dirt in the form of used organic solvents, toxic compounds of metals with waste galvanic and etching solutions, cutting fluids (coolant and emulsions. you need to create complex regeneration treatment system of the most valuable components for these liquids. Reset electroplating and etching solutions can lead to the accumulation of heavy metals in the bio-organisms of the coastal zone and to enter them through the food chain to humans. To prevent contamination, a scheme neutralizing acid waste, accompanied by a reduction in the hazard class of the etching solution to IV class with the ability to accommodate long-term storage solid industrial waste in landfills.

  20. Effect of metallurgical variables on the austenite stability in fatigued AISI 304 type steels

    Czech Academy of Sciences Publication Activity Database

    Man, Jiří; Smaga, M.; Kuběna, Ivo; Eifler, D.; Polák, Jaroslav

    2017-01-01

    Roč. 185, NOV (2017), s. 139-159 ISSN 0013-7944. [XVIII International Colloquium Mechanical Fatigue of Metals. Gijón, 05.11.2016-07.11.2016] R&D Projects: GA ČR GA13-32665S Institutional support: RVO:68081723 Keywords : Austenitic stainless steel * Deformation induced martensite * Color metallography * Chemical banding * Low cycle fatigue Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis Impact factor: 2.151, year: 2016

  1. Mechanism of removal and retention of heavy metals from the acid mine drainage to coastal wetland in the Patagonian marsh.

    Science.gov (United States)

    Idaszkin, Yanina L; Carol, Eleonora; María Del Pilar, Alvarez

    2017-09-01

    The attenuation of the acid mine drainage is one of the most important environmental challenges facing the mining industry worldwide. Mining waste deposits from an ancient metallurgical extraction of heavy metals were found near to the San Antonio marsh in Patagonia. The aim of this work was to determinate which mechanisms regulate the mobilization and retention of metals by acid drainage. A geological and geomorphological survey was carried out and samples from the mining waste deposits and the marsh were collected to determine soil texture, Eh pH, organic matter, Cu, Pb, Zn and Fe content, and soil mineralogical composition. Metals in marsh plants were determined in above- and below-ground structures. In the mining waste deposits polymetallic sulphides were recognized where the oxidation and formation of oxy-hydroxides and sulphates of Fe, Cu, Pb and Zn occurs. Then, by the alteration of those minerals, the metals enter in solution and are mobilized with the surface drainage towards the marsh where adsorption in the soils fine fraction and organic matter and/or by plants occurs. Locally, in the mining waste deposits, the precipitation/dissolution of Cu, Pb, and Zn sulphates take place in small centripetal drainage basins. In topographically lower portions of the marsh desorption and removal of metals by tidal flow could also be happen. The results allow to concluding that the marsh adjacent to the mining waste deposits is a geochemically active environment that naturally mitigates the contamination caused by acid drainage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Laser Induced Breakdown Spectroscopy compared with conventional plasma optical emission techniques for the analysis of metals - A review of applications and analytical performance

    Science.gov (United States)

    Bengtson, A.

    2017-08-01

    This review is focused on a comparison of LIBS with the two most common plasma Optical Emission Spectroscopy (OES) techniques for analysis of metals; spark OES and glow discharge (GD) OES. It is shown that these two techniques have only minor differences in analytical performance. An important part of the paper reviews a direct comparison of the analytical figures of merit for bulk analysis of steels using spark and LIBS sources. The comparison was carried out using one instrument with interchangeable sources, eliminating differences related to the optical system and detectors. It was found that the spark provides slightly better analytical figures of merit. The spark analysis is considerably faster, the simple design of the spark stand has enabled complete automation, both properties of great importance in the metallurgical industry for routine analysis. The analysis of non-metallic inclusions (NMI) with spark and LIBS is presented, in the case of the spark this has become known as Pulse Distribution Analysis (PDA). A very significant difference between the techniques is that the electrical spark typically evaporates 100 times more material than a single laser pulse, resulting in complete evaporation of an NMI present in the evaporated metal. The major advantage of LIBS is that it is localised with very good lateral resolution. The major advantages of spark is that it is much faster (can be done simultaneous with the bulk analysis) and easier to quantify. Compositional Depth Profiling (CDP) is compared for GD-OES and LIBS. It is shown that for applications where GD-OES is well suited, e.g. coated metallic sheet, GD-OES still performs slightly better than LIBS. Similar to the case of NMI analysis, the major advantage of LIBS is the great lateral resolution. This allows elemental surface mapping, as well as CDP of very small areas on μm scale. One further advantage of LIBS is that samples of almost any material, shape and size can be analysed, whereas GD-OES has

  3. Metallurgical and Mechanical Characterization of High Temperature Titanium Alloys Joined by Friction Stir Welding

    Science.gov (United States)

    Gangwar, Kapil Dev

    In the world of joining, riveting and additive manufacturing, weight reduction, and omission of defects (at both macro and micro level) remain of paramount. Therefore, in the wake of ubiquitous fusion welding (FW) and widely accepted approach of riveting using Inconel bolts to resist corrosion at higher temperature, friction stir welding (FSW) has emerged as a novice jewel in friction based additive manufacturing industry. With advancements in automation of welding process and tool material, FSW of materials with higher work hardening such as steel and titanium has also become probable. Process and property relations associated with FSW are inevitable in case of dissimilar titanium alloys, due to presence of heterogeneity (whether atrocious or advantageous) in and around the weld nugget. These process property relationships are needed to be studied and addressed properly in order to optimize the processing window for improved mechanical and metallurgical properties. In this study FSWed similar and dissimilar butt joints of α+β, and near α titanium, alloys have been produced for varying processing conditions in order to study the effect of rotation speed (rpm) and traverse speed (TS; mm-min-1). The aim of this study is to assess the effect of tool geometry, tool rpm, TS on microstructure and mechanical properties of most widely used α+β titanium alloy, Ti-6Al-4V (Ti-64), standard grain and fine grain in addition to α+β,Ti-5Al-4V (T-54M), standard grain, and near α, Ti-6Al-2Mo-4Zr-2Sn (Ti-6242), standard grain (SG) and fine grain (FG). During FSW, a unique α+β fine-grained microstructure has been formed depending on whether or not the peak temperature in the weld nugget (WN) reached above or below β transus temperature. The resulting microstructure consists of acicular α+β, emanating from the prior β grain boundary as the weld cools off. The changes in the microstructure are observed by optical microscopy (OM). Later, a detailed analysis of material

  4. Strengthening and development of raw material basis of rare metals

    International Nuclear Information System (INIS)

    Chistov, L.B.; Zubynin, Yu.L.

    1991-01-01

    Main trends in research programs which lately were way in Giredmet institute are analyzed. They cover a large scope of problems concerning investigations and reprocessing of REM containing ores. A special attention is paid to deeper raw material reprocessing and incidental extraction of REM from non-rare earth ores, metallurgical wastes and used articles, containing rare and rare earth metals. Complex technologies are developed for ore concentration which could be used in the deposits of new commercial types with regard to ecological problems

  5. A metallurgical approach toward alloying in rare earth permanen magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Branagan, Daniel J. [Iowa State Univ., Ames, IA (United States)

    1995-02-23

    The approach was developed to allow microstructural enhancement and control during solidification and processing. Compound additions of Group IVA, VA, or VIA transition metals (TM) and carbon were added to Nd2Fe14B (2-14-1). Transition metal carbides formed in IVA (TiC, ZrC, HfC) and Group VA (VC, NbC, TaC) systems, but not in the VIA system. The alloying ability of each TM carbide was graded using phase stability, liquid and equilibrium solid solubility, and high temperature carbide stability. Ti with C additions was chosen as the best system. The practically zero equilibrium solid solubility means that the Ti and C additions will ultimately form TiC after heat treatment which allows the development of a composite microstructure consisting of the 2-14-1 phase and TiC. Thus, the excellent intrinsic magnetic properties of the 2-14-1 phase remain unaltered and the extrinsic properties relating to the microstructure are enhanced due to the TiC stabilized microstructure which is much more resistant to grain growth. When Ti + C are dissolved in the liquid melt or solid phases, such as the glass or 2-14-1 phase, the intrinsic properties are changed; favorable changes include increased glass forming ability, reduced optimum cooling rate, increased optimum energy product, and enhanced nucleation kinetics of crystallization.

  6. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  7. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  8. Reports on colloquia held at the 1982 Mining and Metallurgical Congress

    Energy Technology Data Exchange (ETDEWEB)

    1982-10-01

    The congress took place in Freiberg, German Democratic Republic, in June 1982. Eleven colloquia are enumerated, major talks held at these colloquia are listed and briefly summarized. Subject of the first two colloquia was surface and underground mining technologies for rock, ore and coal; the following colloquia dealt with new developments in mine surveying and drilling exploration; the fifth colloquium focused on maintenance of mining machines and coal preparation equipment. Colloquia 7 and 8 considered progress in the theory of geophysical exploration of solid mineral resources and progress in the use of isotopes in environmental studies and in hydrogeological exploration. The following colloquia dealt with aspects of chemical utilization of mineral resources, in particular salt, metal, clay and brown coal filter ash. Colloquia 15 and 16 presented themes of mine management and economic assessment in mines. The topic of the last colloquium was the historical development of metallurgy.

  9. Online monitoring of corrosion behavior in molten metal using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Zeng, Qiang; Pan, Congyuan; Li, Chaoyang; Fei, Teng; Ding, Xiaokang; Du, Xuewei; Wang, Qiuping

    2018-04-01

    The corrosion behavior of structure materials in direct contact with molten metals is widespread in metallurgical industry. The corrosion of casting equipment by molten metals is detrimental to the production process, and the corroded materials can also contaminate the metals being produced. Conventional methods for studying the corrosion behavior by molten metal are offline. This work explored the application of laser-induced breakdown spectroscopy (LIBS) for online monitoring of the corrosion behavior of molten metal. The compositional changes of molten aluminum in crucibles made of 304 stainless steel were obtained online at 1000 °C. Several offline techniques were combined to determine the corrosion mechanism, which was highly consistent with previous studies. Results proved that LIBS was an efficient method to study the corrosion mechanism of solid materials in molten metal.

  10. Recovery of metal values from copper slag and reuse of residual secondary slag.

    Science.gov (United States)

    Sarfo, Prince; Das, Avimanyu; Wyss, Gary; Young, Courtney

    2017-12-01

    Resource and environmental factors have become major forces in mining and metallurgy sectors driving research for sustainability purposes. The concept of zero-waste processing has been gaining ground readily. The scant availability of high quality raw materials has forced the researchers to shift their focus to recycling while the exceedingly stringent environmental regulations have forced researchers to explore new frontiers of minimizing/eliminating waste generation. The present work is aimed at addressing both aspects by employing recycling to generate wealth from copper slag and producing utilizable materials at the same time thus restoring the ecosystem. Copper slag was characterized and processed. The pyro-metallurgical processing prospects to generate utilizable materials were arrived at through rigorous thermodynamic analysis. Carbothermal reduction at elevated temperature (near 1440°C) helped recover a majority of the metal values (e.g., Fe, Cu and Mo) into the iron-rich alloy product which can be a feed material for steel making. On the other hand, the non-metallic residue, the secondary slag, can be used in the glass and ceramic industries. Reduction time and temperature and carbon content were shown to be the most important process variables for the reaction which were optimized to identify the most favored operating regime that maximizes the metal recovery and simultaneously maximizes the hardness of the secondary slag and minimizes its density, the two major criteria for the secondary slag product to be utilizable. The flux addition level was shown to have relatively less impact on the process performance if these are maintained at an adequate level. The work established that the copper slag, a waste material, can be successfully processed to generate reusable products through pyrometallurgical processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A importância da utilização de ferramentas da qualidade como suporte para melhoria de processo em indústria metal mecânica – um estudo de caso

    Directory of Open Access Journals (Sweden)

    Mario Fernando de Mello

    2017-01-01

    Full Text Available The constant search to assist and meet the needs of customers means that companies have to find alternatives in their production processes, with clear objectives of continuous improvement, and consequently cost reduction. Having well-defined production processes is a path to the pursuit of efficiency. Processes must always be in continuous improvement in order to minimize processing time, increase efficiency, and thus reduce costs and meet the needs of customers and the company. The present work will deal with the assembly and internal movement of part kits that are sent to the welding process in a metal mechanic company located in the north of Rio Grande do Sul state. Its objectives are to demonstrate the reduction of the waiting time in the assembly of the kits as well as suggest improvements for the process optimization and demonstrate the importance of using quality tools. It was followed by the process of assembly of the kits, the identification and analysis of waiting time failures using quality tools and finally suggested improvements from the data collected. It was demonstrated that from the elaboration of a new workflow and the inclusion of a visual management system, the waiting time was significantly reduced, evidencing the importance of using adequate methodology to solve problems.

  12. Indoor metallic pollution related to mining activity in the Bolivian Altiplano.

    Science.gov (United States)

    Fontúrbel, Francisco E; Barbieri, Enio; Herbas, Cristian; Barbieri, Flavia L; Gardon, Jacques

    2011-10-01

    The environmental pollution associated with mining and metallurgical activities reaches its greatest extent in several Andean cities and villages. Many locations in this area have accumulated through centuries a large amount of mining wastes, often disregarding the magnitude of this situation. However, in these naturally mineralized regions, there is little information available stating the exact role of mining and metallurgical industries in urban pollution. In this study, we demonstrated that the various metallic elements present in indoor dust (As, Cd, Cu, Pb, Sb, Sn, Zn) had a common origin and this contamination was increased by the proximity to the mines. Lead dust concentration was found at concerning levels for public health. In addition, wrong behaviors such as carrying mining workwear home contributed to this indoor dust pollution. Consequently, the constant exposure of the population could represent a potential health hazard for vulnerable groups, especially children. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Modification of Non-Metallic Inclusions by Rare-Earth Elements in Microalloyed Steels

    Directory of Open Access Journals (Sweden)

    M. Opiela

    2012-04-01

    Full Text Available The modification of the chemical composition of non-metallic inclusions by rare-earth elements in the new-developed microalloyed steels was discussed in the paper. The investigated steels are assigned to production of forged elements by thermo- mechanical treatment. The steels were melted in a vaccum induction furnace and modification of non-metallic inclusions was carried out by the michmetal in the amount of 2.0 g per 1 kg of steel. It was found that using material charge of high purity and a realization of metallurgical process in vacuous conditions result in a low concentration of sulfur (0.004%, phosphorus (from 0.006 to 0.008% and oxygen (6 ppm. The high metallurgical purity is confirmed by a small fraction of non-metallic inclusions averaging 0.075%. A large majority of non-metallic inclusions are fine, globular oxide-sulfide or sulfide particles with a mean size 17m2. The chemical composition and morphology of non-metallic inclusions was modified by Ce, La and Nd, what results a small deformability of non- metallic inclusions during hot-working.

  14. Tritium in metals

    International Nuclear Information System (INIS)

    Schober, T.

    1990-01-01

    In this Chapter a review is given of some of the important features of metal tritides as opposed to hydrides and deuterides. After an introduction to the topics of tritium and tritium in metals information will be presented on a variety of metal-tritium systems. Of main interest here are the differences from the classic hydrogen behavior; the so called isotope effect. A second important topic is that of aging effects produced by the accumulation of 3 He in the samples. (orig.)

  15. Metal-metal-hofteproteser

    DEFF Research Database (Denmark)

    Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

    2014-01-01

    In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo...

  16. Evaluation of the electrorefining technique for the processing of radioactive scrap metals

    Energy Technology Data Exchange (ETDEWEB)

    Kessinger, G.F.

    1993-10-01

    This report presents the results of a literature study performed to identify applications of the electrorefining technique to the decontamination of radioactively-contaminated scrap metal (RSM). Upon the completion of the literature search and the review of numerous references, it was concluded that there were applications of this technique that were appropriate for the decontamination of some types of RSM, especially when the desired product is a pure elemental metal of high purity. It was also concluded that this technique was not well-suited for the decontamination of RSM stainless steels and other alloys, when it was desired that the metallurgical characteristics of the alloy be present in the decontaminated product.

  17. Evaluation of the electrorefining technique for the processing of radioactive scrap metals

    International Nuclear Information System (INIS)

    Kessinger, G.F.

    1993-10-01

    This report presents the results of a literature study performed to identify applications of the electrorefining technique to the decontamination of radioactively-contaminated scrap metal (RSM). Upon the completion of the literature search and the review of numerous references, it was concluded that there were applications of this technique that were appropriate for the decontamination of some types of RSM, especially when the desired product is a pure elemental metal of high purity. It was also concluded that this technique was not well-suited for the decontamination of RSM stainless steels and other alloys, when it was desired that the metallurgical characteristics of the alloy be present in the decontaminated product

  18. Integrating Fiber Optic Strain Sensors into Metal Using Ultrasonic Additive Manufacturing

    Science.gov (United States)

    Hehr, Adam; Norfolk, Mark; Wenning, Justin; Sheridan, John; Leser, Paul; Leser, Patrick; Newman, John A.

    2017-12-01

    Ultrasonic additive manufacturing, a rather new three-dimensional (3D) printing technology, uses ultrasonic energy to produce metallurgical bonds between layers of metal foils near room temperature. This low temperature attribute of the process enables integration of temperature sensitive components, such as fiber optic strain sensors, directly into metal structures. This may be an enabling technology for Digital Twin applications, i.e., virtual model interaction and feedback with live load data. This study evaluates the consolidation quality, interface robustness, and load sensing limits of commercially available fiber optic strain sensors embedded into aluminum alloy 6061. Lastly, an outlook on the technology and its applications is described.

  19. Integrating Fiber Optic Strain Sensors into Metal Using Ultrasonic Additive Manufacturing

    Science.gov (United States)

    Hehr, Adam; Norfolk, Mark; Wenning, Justin; Sheridan, John; Leser, Paul; Leser, Patrick; Newman, John A.

    2018-03-01

    Ultrasonic additive manufacturing, a rather new three-dimensional (3D) printing technology, uses ultrasonic energy to produce metallurgical bonds between layers of metal foils near room temperature. This low temperature attribute of the process enables integration of temperature sensitive components, such as fiber optic strain sensors, directly into metal structures. This may be an enabling technology for Digital Twin applications, i.e., virtual model interaction and feedback with live load data. This study evaluates the consolidation quality, interface robustness, and load sensing limits of commercially available fiber optic strain sensors embedded into aluminum alloy 6061. Lastly, an outlook on the technology and its applications is described.

  20. State-of-art of modern technologies for metals production

    Energy Technology Data Exchange (ETDEWEB)

    Holappa, L. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Metallurgy

    1995-12-31

    The future raw materials are becoming lower in metal content and more complex, multimetal concentrates will be utilized. This will give challenges for metallurgists to develop new, efficient and energy saving processes. The main impacts for current and future production technologies come from energy need and environmental issues of the production processes themselves as well as the inevitable energy production for the metal making. Metals production consumes huge amount of energy, roughly 10 pct of the global energy consumption is caused by metallurgists. That is the necessity but it also means energy saving is one of the metallurgical industry have been enormous when looking back to the history. Since the 1960`s the efforts of the industry together with the strict legislation in the industrialized countries have conducted to greatly decreased emissions and improved pollution control. Breakthrough of new processes like copper flash smelting has aided this positive progress

  1. Environmental management and educational needs of the small and medium-sized businesses of the metallurgical sector in the south region of Madrid

    International Nuclear Information System (INIS)

    Urena, A.; Rams, J.; Mendez, F. J.; Rodriguez, J.

    2004-01-01

    In this study, the environmental management and needs of the small and medium-sized businesses of the metallurgical industry in the south region of Madrid were analysed. Information was obtained through a telephone questionnaire distributed to more than 170 companies. Although most of the respondent employees do not consider environmental training one of their priorities, they expressed their interest in implementing Environmental Management Systems, waste minimization and higher knowledge of the specific legal aspects. (Author) 7 refs

  2. Assessment of the effect of Nd:YAG laser pulse operating parameters on the metallurgical characteristics of different tool steels using DOE software

    OpenAIRE

    Muhič, T.; Kosec, L.; Liedl, G.; Pleterski, M.

    2011-01-01

    To ensure the reliability of repair welded tool surfaces, clad quality should be improved. The relationships between metallurgical characteristics of cladding and laser input welding parameters were studied using the design of experiments software. The influence of laser power, welding speed, focal point position and diameter of welding wire on the weld-bead geometry (i.e. penetration, cladding zone width and heat-affected-zone width), microstructural homogeneity, dilution and bond strength w...

  3. Imported biofuels

    International Nuclear Information System (INIS)

    Sieurin, J.

    1992-01-01

    No import of biofuels to Sweden for energy production existed before 1991. That year, import of wood chips from Latvia and olive wastes (pits) from the Mediterranean region started, with volumes corresponding to 100 GWh each. This fuels were used in district heating plants, with converted coal boilers. The price was about 120 SEK/MWh (∼ 18 USD/MWh) at the plant. Small amounts of wood pellets were imported from Poland, Canada and Denmark, totalling less than 100 GWh. This fuel was used by small heating centrals and the import was caused by a shortage of swedish pellets. Potentially important export countries, if a large scale biofuel use starts in Sweden, are Russia, the Baltic states, USA, and Canada. Technical possibilities for converting coal-fired boilers to biofuel firing are discussed in a four page section of this paper. (2 refs., 2 tabs.)

  4. Immobilization of zinc from metallurgical waste and water solutions using geopolymerization technology

    Directory of Open Access Journals (Sweden)

    Nikolići I.

    2014-07-01

    Full Text Available Geopolymeraization technology is recognized as a promising method for immobilization of heavy metals by the stabilization or solidification process. This process involves the chemical reaction of alumino-silicate oxides with highly alkaline activator yielding the new material with amorphous or semi-amorphous structure, called geopolymer. Fly ash and blast furnace slag were mainly used as a raw material for geopolymerization process. In this paper we have investigated the possibility of immobilization of Zn from electric arc furnace dust (EAFD through geopolymerization of fly ash and possibility of Zn2+ adsorption from waste waters using fly ash based geopolymers. Efficacy of Zn immobilization from electric arc furnace dust was evaluated by TCLP test while the immobilization of Zn2+ ions from the water solution was evaluated through the removal efficiency. The results have shown that geopolymerization process may successfully be used for immobilization of Zn by stabilization of EAFD and for production of low cost adsorbent for waste water treatment.

  5. Metallurgical and mechanical properties of laser welded high strength low alloy steel.

    Science.gov (United States)

    Oyyaravelu, Ramachandran; Kuppan, Palaniyandi; Arivazhagan, Natarajan

    2016-05-01

    The study aimed at investigating the microstructure and mechanical properties of Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser welded high strength low alloy (HSLA) SA516 grade 70 boiler steel. The weld joint for a 4 mm thick plate was successfully produced using minimum laser power of 2 kW by employing a single pass without any weld preheat treatment. The micrographs revealed the presence of martensite phase in the weld fusion zone which could be due to faster cooling rate of the laser weldment. A good correlation was found between the microstructural features of the weld joints and their mechanical properties. The highest hardness was found to be in the fusion zone of cap region due to formation of martensite and also enrichment of carbon. The hardness results also showed a narrow soft zone at the heat affected zone (HAZ) adjacent to the weld interface, which has no effect on the weld tensile strength. The yield strength and ultimate tensile strength of the welded joints were 338 MPa and 549 MPa, respectively, which were higher than the candidate metal. These tensile results suggested that the laser welding process had improved the weld strength even without any weld preheat treatment and also the fractography of the tensile fractured samples showed the ductile mode of failure.

  6. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  7. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  8. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  9. Left-wing, democracy, and trade union insurgency in Mexico: nuclear, mining, and metallurgical workers, 1972-1985

    Directory of Open Access Journals (Sweden)

    Gerardo Necoechea Gracia

    2016-03-01

    Full Text Available This article analyzes the history of trade union insurgency in Mexico during the 1970s and the relationship established between the left and the labor class. To do this, experiences of the Mexican National Nuclear Energy Trade Union and those of sections 11 and 147 of the mining-metallurgical trade union are analyzed. In the first case, its relationship with the democratic movement of electrical workers and the current of revolutionary nationalism are observed and in the second its links with the political organization Línea Proletaria, which has a Maoist affiliation. Both currents proposed various strategies that revived the tension existing in the Mexican labor movement in the early century, between those who thought that trade unions should not ally to political parties and instead exert direct action at work and those who advocated for political alliances, which they called multiple action. Both movements converged in the trade union movement of that period, which demanded trade union democracy and demonstrated against the austerity policy imposed by the government, as well as for the defense of natural resources. On the other hand, labor activism was manifested in an environment of greater rebelliousness combined with other social groups, a situation that ascertains advances in the struggles of workers from the industry and services, and its impact on the political, social, and cultural life in the country.

  10. Microstructure and tribology behaviors of in-situ WC/Fe carbide coating fabricated by plasma transferred arc metallurgic reaction

    Science.gov (United States)

    Yuan, Youlu; Li, Zhuguo

    2017-11-01

    In order to improve the dry sliding tribology properties of mild steel compound, the in-situ WC carbide coatings with 18, 32, 54 vol% WC were successfully synthesized using plasma transferred arc metallurgic reaction (PTAMR) with alloy powders W, C and Fe-30Ni. The composition, microstructure and microhardness of the carbide coatings were characterized. It was found that the carbide coating consisted of WC, M6C and γ phases, carbides distribute gradually from the coating bottom to top, the in-situ WC crystal grows into triangle prism structure with high hardness and good toughness. Dry sliding tribology behaviors were studied on block-on-wheel dry sliding wear tester with load 300 N, sliding speed 0.836 m/s and distance 500 m. Results show that the friction coefficient diagrams contain three stages, variation of friction coefficient increase with the content of WC, friction temperature increase with the sliding distance, increasing the content of WC can directly increase the antiwear property of WC/Fe carbide coating. The main wear mechanisms of in-situ WC/Fe carbide coating are adhesive, oxidation, micro-cutting and ploughing wear.

  11. Effects of metallurgical factors on stress corrosion cracking of Ni-base alloys in high temperature water

    International Nuclear Information System (INIS)

    Yonezawa, T.; Sasaguri, N.; Onimura, K.

    1988-01-01

    Nickel-base Alloy 600 is the principal material used for the steam generator tubes of PWRs. Generally, this alloy has been proven to be satisfactory for this application, however when it is subjected to extremely high stress level in PWR primary water, it may suffer from stress corrosion cracking. The authors have systematically studied the effects of test temperature and such metallurgical factors as cold working, chemical composition and heat treatment on the stress corrosion cracking of Alloy 600 in high temperature water, and also on that of Alloy 690 which is a promising material for the tubes and may provide improved crrosion resistance for steam generators. The test materials, the stress corrosion cracking test and the test results are reported. When the test temperature was raise, the stress corrosion cracking of the nickel-base alloys was accelerated. The time of stress corrosion cracking occurrence decreased with increasing applied stress, and it occurred at the stress level higher than the 0.2 % offset proof stress of Alloy 600. In Alloy 690, stress corrosion cracking was not observed at such stress level. Cold worked Alloy 600 showed higher resistance to stress corrosion cracking than the annealed alloy. (Kako, I.)

  12. Projects development for mining-metallurgical units for production of uranium concentrates. An analysis an a methodology

    International Nuclear Information System (INIS)

    Ajuria G, S.; Blanco P, B.; Manzanera Q, C.; Pena A, J.

    1978-07-01

    An analysis and a methodology for the complete development of a mining- metallurgist project is presented, from the sampling and the evaluation of a deposit until the outburst of a metallurgical plant. The main objectives of this work are three: On one hand it is to establish a methodology for standardize the internal activities of the Sub management of Benefits. It is convenient standardize the experimental procedures, the evaluation approaches and the form of presentation of results so that they are directly comparable and that it is easy their interpretation and use. Given the nature so variable of the minerals this document cannot be but that a guide and it is indispensable that in all moment the personnel that develops these activities uses his knowledge, experience and professional approach to obtain the best results. On the other hand it is to establish a base to facilitate the coordination of the activities of the Sub management of Benefit with other work groups, inside of and outside of the INEN that should collaborate in the projects. Finally it is to present a vision of group of the whole project like reference base for the participant personnel. Many of the specialists that contribute to the project would not be metallurgists, but rather they practice other disciplines. It is therefore convenient to facilitate the one that are formed an image of the complete project. (Author)

  13. IMPORTANT NOTIFICATION

    CERN Multimedia

    HR Department

    2009-01-01

    Green plates, removals and importation of personal effects Please note that, as from 1 April 2009, formalities relating to K and CD special series French vehicle plates (green plates), removals and importation of personal effects into France and Switzerland will be dealt with by GS Department (Building 73/3-014, tel. 73683/74407). Importation and purchase of tax-free vehicles in Switzerland, as well as diplomatic privileges, will continue to be dealt with by the Installation Service of HR Department (Building 33/1-011, tel. 73962). HR and GS Departments

  14. POWER, METALLURGICAL AND CHEMICAL MECHANICAL ENGINEERING THERMOELECTRIC EVENTS IN LIGHT-EMITTING BIPOLAR SEMICONDUCTOR STRUCTURES

    Directory of Open Access Journals (Sweden)

    P. A. Magomedova

    2017-01-01

    Full Text Available Objective. The development of light-emitting bipolar semiconductor structures having a low level of parasitic heat release.Methods. A method for converting thermoelectric heat in bipolar semiconductor structures into optical radiation to divert the excess energy into the environment was developed. At the same time, the cooling effect on thermoelectric junctions remains. Instead of an inertial process of conductive or convective heat transfer, practically instantaneous heat removal from electronic components to the environment takes place.Results. As a result, light-emitting bipolar semiconductor structures will allow more powerful devices with greater speed and degree of integration to be created. It is possible to produce transparent LED matrices with a two-way arrangement of transparent solar cells and mirror metal electrodes along the perimeter. When current is applied, the LED matrix on one of the transitions will absorb thermal energy; on other electrodes, it will emit radiation that is completely recovered into electricity by means of transparent solar cells following repeated reflection between the mirror electrodes. The low efficiency of solar cells will be completely compensated for with the multiple passages of photons through these batteries.Conclusion. Light-emitting bipolar semiconductor structures will not only improve the reliability of electronic components in a wide range of performance characteristics, but also improve energy efficiency through the use of optical radiation recovery. Semiconductor thermoelectric devices using optical phenomena in conjunction with the Peltier effect allow a wide range of energy-efficient components of radio electronic equipment to be realised, both for discrete electronics and for microsystem techniques. Systems for obtaining ultra-low temperatures in order to achieve superconductivity are of particular value. 

  15. Femtosecond fiber laser welding of dissimilar metals.

    Science.gov (United States)

    Huang, Huan; Yang, Lih-Mei; Bai, Shuang; Liu, Jian

    2014-10-01

    In this paper, welding of dissimilar metals was demonstrated for the first time, to the best of our knowledge, by using a high-energy high-repetition-rate femtosecond fiber laser. Metallurgical and mechanical properties were investigated and analyzed under various processing parameters (pulse energy, repetition rate, and welding speed). Results showed that the formation of intermetallic brittle phases and welding defects could be effectively reduced. Strong welding quality with more than 210 MPa tensile strength for stainless steel-aluminum and 175 MPa tensile strength for stainless steel-magnesium has been demonstrated. A minimal heat affected zone and uniform and homogenous phase transformation in the welding region have been demonstrated. This laser-welding technique can be extended for various applications in semiconductor, automobile, aerospace, and biomedical industries.

  16. Direct metal laser sintering: a digitised metal casting technology.

    Science.gov (United States)

    Venkatesh, K Vijay; Nandini, V Vidyashree

    2013-12-01

    Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

  17. Physics of amorphous metals

    CERN Document Server

    Kovalenko, Nikolai P; Krey, Uwe

    2008-01-01

    The discovery of bulk metallic glasses has led to a large increase in the industrial importance of amorphous metals, and this is expected to continue. This book is the first to describe the theoretical physics of amorphous metals, including the important theoretical development of the last 20 years.The renowned authors stress the universal aspects in their description of the phonon or magnon low-energy excitations in the amorphous metals, e.g. concerning the remarkable consequences of the properties of these excitations for the thermodynamics at low and intermediate temperatures. Tunneling

  18. THE METALLURGICAL SPECIFICATIONS AND HARDNESS PROFILE OF A RAIL THERMITE WELD

    OpenAIRE

    Cevdet MERİÇ; Turgut ENGEZ

    1998-01-01

    The quality of railroad construction is a important factor for comfort and safety in railroad transportation. Thermite welding being known for a long time prevents rail failure and, off road the train. It provides smoothly journey, and long life to rails and wagons. In this study, S 49 type St 70 steel rails have been welded by thermite process, hardness profile of welding zone rails has been obtained and its microstructure has been examined. In this profile maximum hardness values have been ...

  19. Evaluation of industrial rejects of mineral and metallurgical processing as ceramic synthetic proppants

    OpenAIRE

    Campos, Vitor Polezi Pesce de; Toffoli, Samuel Marcio; Gouvea, Douglas; Silva, Guilherme Frederico Bernardo Lenz e

    2014-01-01

    Hydraulic fracturing is a very important technique to increase the productivity and recovery of oil reservoirs with low pressure or high depth. The hydraulic fracturing technique is a method of well stimulation in which liquid under high pressure is pumped down a well to fracture the reservoir rock adjacent to the wellbore. Propping agents are used to keep the fractures/cracks open. They can be made from the reject of mineral extraction processes when they present specifics characteristic. Th...

  20. Internal sources of risk in building employees’ attitudes of safe work in metallurgical enterprise

    Directory of Open Access Journals (Sweden)

    K. Grzybowska

    2013-04-01

    Full Text Available The aim of the article is the identification of the internal sources of risk in the process of improving the system of safety and work hygiene management. After conduction of the analysis the conclusion is that the significant source of risk in the process of improvement of safety and work hygiene management is the human factor and, in particular, the lack of employees’ awareness concerning the importance of their attitudes in the improvement of the system.

  1. Service Supply Chains Performance Improvement Method: The Case of Supplier Selection in the Metallurgical Sector

    Directory of Open Access Journals (Sweden)

    Miguel Gastón Cedillo-Campos

    2015-01-01

    Full Text Available Introducción: El servicio es ahora un componente clave del crecimiento económico de las naciones modernas. Bajo un ambiente de competencia dinámica global, el incremento en las capacidades de servicio de las cadenas de suministro se ha vuelto vital. Para las empresas operando en mercados emergentes, el continuo incremento en los requerimientos de los clientes, ha resultado en desafiantes procesos de mejora continua en el servicio. En éste contexto, el artículo presenta un método desarrollado desde la perspectiva de la medición del desempeño de los proveedores de servicio en cadenas de suministro, el cual además contó para su implementación, con una herramienta informática de fácil utilización. Método: Con base en un caso de estudio del sector metalúrgico en México, la principal contribución de este artículo es el exponer un método para la evaluación de proveedores de servicio, el cual fue desarrollado desde un enfoque de mejora continua. Es un método hibrido que liga la aplicación de herramientas estratégicas, con el análisis de decisiones multicriterio para la mejora del desempeño de cadenas de suministro del servicio. Resultados: Desde una perspectiva de cadena de suministro, este enfoque aplicado es de ayuda tanto para académicos, como para profesionales quienes se enfrentan a la compleja tarea de evaluar proveedores de servicio en cadenas de suministro que operan en mercados emergentes. Discusión o Conclusión: El método propuesto aporta visibilidad y transparencia sobre el desempeño de los proveedores de servicio a todos los miembros de la cadena de suministro. Se trata de información preventiva acerca del desempeño de los proveedores, lo cual ayuda a reducir los costos de remplazar a aquellos con bajo desempeño. Comparado con otros enfoques, la principal ventaja del método propuesto es la integración de los enfoques cuantitativo y cualitativo para la medición del servicio con el propósito de mejora

  2. Metallurgical characterization of new palladium-containing cobalt chromium and nickel chromium alloys

    Science.gov (United States)

    Puri, Raghav

    Recently introduced to the market has been an entirely new subclass of casting alloy composition whereby palladium (˜25 wt%) is added to traditional base metal alloys such as CoCr and NiCr. Objectives. The purpose of this study was to evaluate the microstructure and Vickers hardness of two new CoPdCr and one new NiPdCr alloy and compare them to traditional CoCr and NiCr alloys. Methods. The casting alloys investigated were: CoPdCr-A (Noble Crown NF, The Argen Corporation), CoPdCr-I (Callisto CP+, Ivoclar Vivadent), NiPdCr (Noble Crown, Argen), CoCr (Argeloy N.P. Special, Argen), and NiCr (Argeloy N.P. Star, Argen). As-cast cylindrical alloy specimens were mounted in epoxy resin and prepared with standard metallographic procedures, i.e. grinding with successive grades of SiC paper and polishing with alumina suspensions. The alloys were examined with an optical microscope, SEM/EPMA, and XRD to gain insight into their microstructure, composition, and crystal structure. Vickers hardness (VHN) was measured and statistically analyzed by one way ANOVA and Tukey's HSD test (alpha=0.05). Results. Optical microscopy showed a dendritic microstructure for all alloys. The Pd-containing alloys appear to possess a more complex microstructure. SEM/EPMA showed Cr to be rather uniformly distributed in the matrix with palladium tending to be segregated apart from Mo and Ni or Co. Areas of different composition may explain the poor electrochemical results noted in previous studies. XRD suggested the main phase in the Ni-containing solutions was a face centered cubic Ni solid solution, whereas the CoCr exhibited a hexagonal crystal structure that was altered to face centered cubic when Pd was included in the composition. For Vickers hardness, the Co-containing alloys possessed a greater hardness than the Ni-containing alloys. However, the incorporation of Pd in CoCr and NiCr had only a slight effect on microhardness. Conclusion. Overall, the inclusion of palladium increases the

  3. Recovery of metals and nonmetals from electronic waste by physical and chemical recycling processes.

    Science.gov (United States)

    Kaya, Muammer

    2016-11-01

    This paper reviews the existing and state of art knowledge for electronic waste (e-waste) recycling. Electrical and/or electronic devices which are unwanted, broken or discarded by their original users are known as e-waste. The main purpose of this article is to provide a comprehensive review of e-waste problem, strategies of e-waste management and various physical, chemical and metallurgical e-waste recycling processes, their advantages and disadvantages towards achieving a cleaner process of waste utilization, with special attention towards extraction of both metallic values and nonmetallic substances. The hazards arise from the presence of heavy metals Hg, Cd, Pb, etc., brominated flame retardants (BFRs) and other potentially harmful substances in e-waste. Due to the presence of these substances, e-waste is generally considered as hazardous waste and, if improperly managed, may pose significant human and environmental health risks. This review describes the potential hazards and economic opportunities of e-waste. Firstly, an overview of e-waste/printed circuit board (PCB) components is given. Current status and future perspectives of e-waste/PCB recycling are described. E-waste characterization, dismantling methods, liberation and classification processes are also covered. Manual selective dismantling after desoldering and metal-nonmetal liberation at -150μm with two step crushing are seen to be the best techniques. After size reduction, mainly physical separation processes employing gravity, electrostatic, magnetic separators, froth floatation, etc. have been critically reviewed here for separation of metals and nonmetals, along with useful utilizations of the nonmetallic materials. The recovery of metals from e-waste material after physical separation through pyrometallurgical, hydrometallurgical or biohydrometallurgical routes is also discussed along with purification and refining. Suitable PCB recycling flowsheets for industrial applications are also given

  4. Metal-metal-hofteproteser

    DEFF Research Database (Denmark)

    Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

    2014-01-01

    In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo......M hip implant. A Danish surveillance programme has been initiated addressing these problems....

  5. Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

    Directory of Open Access Journals (Sweden)

    Maryam Moravej

    2011-06-01

    Full Text Available During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

  6. THE METALLURGICAL SPECIFICATIONS AND HARDNESS PROFILE OF A RAIL THERMITE WELD

    Directory of Open Access Journals (Sweden)

    Cevdet MERİÇ

    1998-02-01

    Full Text Available The quality of railroad construction is a important factor for comfort and safety in railroad transportation. Thermite welding being known for a long time prevents rail failure and, off road the train. It provides smoothly journey, and long life to rails and wagons. In this study, S 49 type St 70 steel rails have been welded by thermite process, hardness profile of welding zone rails has been obtained and its microstructure has been examined. In this profile maximum hardness values have been observed in front of welding region. Hardness value was 290 HB in the front of melting zone in the zone under heat effect (HAZ, 260 HB in welding zone and 220 HB in main structure. For microstructure pro-eutectoid ferrite and perlite were observed but not martensite.

  7. Metallurgical analysis and RF losses in superconducting niobium thin film cavities

    CERN Document Server

    Bloess, D; Mahner, E; Nakai, H; Weingarten, Wolfgang; Bosland, P; Mayer, J; Van Loyen, L

    1996-01-01

    Copper cavities with a thin niobium film as used in the large electron positron collider LEP would be also attractive for future linear colliders, provided the decrease of the Q-value with the accelerating gradient can be reduced. We aim at extracting the important parameters that govern this decrease. The dependence on the RF frequency is studied by exciting 500 MHz and 1500 MHz cavities in different modes. In addition we combined RF measurements for two 1500 MHz cavities of different RF performance with microscopic tests (AFM, TEM) on samples cut out of the same cavities. Their micro-structural characterisation in plan-view allows to extract the grain size and the defect densities.

  8. Liquid Metal Transformers

    OpenAIRE

    Sheng, Lei; Zhang, Jie; Liu, Jing

    2014-01-01

    The room temperature liquid metal is quickly emerging as an important functional material in a variety of areas like chip cooling, 3D printing or printed electronics etc. With diverse capabilities in electrical, thermal and flowing behaviors, such fluid owns many intriguing properties that had never been anticipated before. Here, we show a group of unconventional phenomena occurring on the liquid metal objects. Through applying electrical field on the liquid metals immersed in water, a series...

  9. Effects of metallurgical variables on swelling of modified 316 and higher Ni austenitic stainless steels

    International Nuclear Information System (INIS)

    Shibahara, Itaru; Akasaka, Naoaki; Onose, Shoji

    1996-01-01

    The effects of solute elements and cold-work on swelling in modified 316 and higher Ni advanced austenitic stainless steels developed for FBR core material were investigated together with the posted model alloys. The Si, P, B, Ti, Nb modified and cold-worked steels exhibited an improved swelling resistance. In the temperature range between 400 and 500 C, the swelling was suppressed significantly by an addition of 0.8 wt% Si. The beneficial effect of Si appears to be reduced in the steels without Ti and Nb tending to form γ' precipitates. In the temperature range between 500 and 600 C, a needle-like phosphide precipitates played an important role in suppressing void growth. Additions of Ti and/or Nb were found to stabilize the phosphide phase and extended the swelling incubation period. In the improved austenitic steels, the synergistic effect of cold-working and P, B, Ti, Nb additions act beneficially to stabilize the dislocation structure and to form finely dispersed precipitates during irradiation

  10. Influence of coal batch preparation on the quality of metallurgical соkе

    Directory of Open Access Journals (Sweden)

    Катерина Олегівна Шмельцер

    2015-10-01

    Full Text Available To study the influence of coal batch properties on coke strength we have considered the quality of the coke produced at the plant in Krivoy Rog from 2008 till 2012. Such factors as the large number of coal suppliers, imprecise selection of the optimal degree of batch crushing result in the decline in coke quality, the batch density and contents of the lean class (<0,5 mm are not optimum; poor blending of the batch after crushing; increased moisture and ash content of the coking batch; and extreme fluctuation in the coal and batch characteristics. It was found that high humidity of coal batch and its large fluctuations has most profound effect on the mechanical properties of coke. Under deteriorating resource base the quality of the coking batch preparation is important, To have batch of proper quality the following key aspects must be taken into account: the batch must be crushed to an optimum degree that will result in leaning components decrease and increased contents of vitrivite in it which improves the sinterability and coking, and hence the quality of coke; the degree of mixing of the coking batch in all indices must be up to 98-99%, for uneven distribution in the coal chamber worsens the quality of coke

  11. Metallurgy and mechanical properties variation with heat input,during dissimilar metal welding between stainless and carbon steel

    Science.gov (United States)

    Ramdan, RD; Koswara, AL; Surasno; Wirawan, R.; Faturohman, F.; Widyanto, B.; Suratman, R.

    2018-02-01

    The present research focus on the metallurgy and mechanical aspect of dissimilar metal welding.One of the common parameters that significantly contribute to the metallurgical aspect on the metal during welding is heat input. Regarding this point, in the present research, voltage, current and the welding speed has been varied in order to observe the effect of heat input on the metallurgical and mechanical aspect of both welded metals. Welding was conducted by Gas Metal Arc Welding (GMAW) on stainless and carbon steel with filler metal of ER 309. After welding, hardness test (micro-Vickers), tensile test, macro and micro-structure characterization and Energy Dispersive Spectroscopy (EDS) characterization were performed. It was observed no brittle martensite observed at HAZ of carbon steel, whereas sensitization was observed at the HAZ of stainless steel for all heat input variation at the present research. Generally, both HAZ at carbon steel and stainless steel did not affect tensile test result, however the formation of chromium carbide at the grain boundary of HAZ structure (sensitization) of stainless steel, indicate that better process and control of welding is required for dissimilar metal welding, especially to overcome this issue.

  12. Genotoxicity and cytotoxicity response to environmentally relevant complex metal mixture (Zn, Cu, Ni, Cr, Pb, Cd) accumulated in Atlantic salmon (Salmo salar). Part I: importance of exposure time and tissue dependence.

    Science.gov (United States)

    Stankevičiūtė, Milda; Sauliutė, Gintarė; Svecevičius, Gintaras; Kazlauskienė, Nijolė; Baršienė, Janina

    2017-10-01

    Health impact of metal mixture at environment realistic concentrations are difficult to predict especially for long-term effects where cause-and-effect relationships may not be directly obvious. This study was aimed to evaluate metal mixture (Zn-0.1, Cu-0.01, Ni-0.01, Cr-0.01, Pb-0.005 and Cd-0.005 mg/L, respectively for 1, 2, 4, 7, 14 and 28 days at concentrations accepted for the inland waters in EU) genotoxicity (micronuclei, nuclear buds, nuclear buds on filament), cytotoxicity (8-shaped nuclei, fragmented-apoptotic erythrocytes), bioaccumulation, steady-state and the reference level of geno-cytotoxicity in hatchery-reared Atlantic salmon tissues. Metals accumulated mostly in gills and kidneys, to the lesser extent in the muscle. Uptake of metals from an entire mixture in the fish for 14 days is sufficient to reach steady-state Cr, Pb concentrations in all tissues; Zn, Cu-in kidneys and muscle, Ni-in liver, kidneys, muscle and Cd-in muscle. Treatment with metal mixture significantly increased summed genotoxicity levels at 7 days of exposure in peripheral blood and liver erythrocytes, at 14 days of exposure in gills and kidney erythrocytes. Significant elevation of cytotoxicity was detected after 2 and 14 days of exposure in gills erythrocytes and after 28 days-in peripheral blood erythrocytes. The amount of Cu, Cr, Pb and Cd accumulated in tissues was dependent upon duration of exposure; nuclear buds, 8-shaped nuclei frequencies also were dependent upon duration of exposure. This study indicates that metals at low levels when existing in mixture causes significant geno-cytotoxicity responses and metals bioaccumulation in salmon.

  13. Thermochemistry of brazing ceramics and metals in air

    Energy Technology Data Exchange (ETDEWEB)

    Bobzin, Kirsten; Schlaefer, Thomas; Kopp, Nils [RWTH Aachen (DE). Surface Engineering Inst. (IOT)

    2011-08-15

    Reactive air brazing offers economically and technologically advantageous joining of ceramics to metals. Solid oxide fuel cells and membranes for oxyfuel combustion are recent fields of application. However, it remains a problem that strong metallurgical reactions between brazes and base materials occur. These reactions were analysed by differential scanning calorimetry tests to get a better understanding. Therefore, three braze alloys (Ag8Cu, Ag8Cu0.5Ti and Ag4Cu4Ni) and five base materials (alumina, 3YSZ partially stabilised zirconia, BSCF perovskite ceramic, X1CrTi-La22 and X15CrNiSi25-20) were investigated. The reaction peaks correlate with the formation of reaction layers, which were observed in metallographic analysis of brazed specimens. The results help to explain the reaction mechanisms and allow optimised selection of filler metals and brazing temperature. (orig.)

  14. Development of dissimilar metal transition joint by hot bond rolling

    International Nuclear Information System (INIS)

    Kurokawa, Hiroyuki; Nakasuji, Kazuyuki; Kajimura, Haruhiko; Nagai, Takayuki; Takeda, Seiichiro.

    1997-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called 'rotary reduction mill'. This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed. (author)

  15. Changes in thermal plasticity of low grade coals during selective extraction of metals

    Directory of Open Access Journals (Sweden)

    В. Ю. Бажин

    2016-08-01

    Full Text Available As the world oil market tends to be highly volatile, the coal becomes a primary source of organic raw materials for chemical and metallurgical industries. Fossil coals can accumulate high amounts of elements and mixtures quite often reaching commercially valuable concentrations. Reserves of scandium and other rare elements in coal deposits in Siberia alone are sufficient to satisfy the expected global demand for several decades. This study is intended to solve complex tasks associated with extraction of metal oxides using the developed enrichment method to ensure the required thermal plasticity determining the quality and properties of metallurgical coke.Laboratory experiments have been conducted for the enrichment of high-ash coals containing the highest concentrations of metals. Thermal plasticity values have been determined with the help of Gieseler plastometer . Using modern technologies and equipment individual deposits can be turned into profitable production of enriched coking coals with concurrent extraction of rare metals. It has been proven that the highest commercial potential lies with the extraction of scandium and some other rare metals in the form of oxides from the coal.

  16. M-Area and Metallurgical Laboratory Hazardous Waste Management Facilities Groundwate Monitoring and Corrective-Action Report, First and Second Quarters 1998, Volumes I, II, & III

    Energy Technology Data Exchange (ETDEWEB)

    Chase, J.

    1998-10-30

    This report describes the groundwater monitoring and corrective-action program at the M-Area Hazardous waste Management Facility (HWMF) and the Metallurgical Laboratory (Met Lab) HWMF at the Savannah river Site (SRS) during first and second quarters 1998. This program is required by South Carolina Hazardous Waste Permit SC1-890-008-989 and Section 264.100(g) of the South Carolina Hazardous Waste Management Regulations. Report requirements are described in the 1995 RCRA Renewal Permit, effective October 5, 1995, Section IIIB.H.11.b for the M-Area HWMF and Section IIIG.H.11.b for the Met Lab HWMF.

  17. Coal Mining and Post-Metallurgic Dumping Grounds and Their Connections with Exploitation of Raw Materials in the Region of Ruda Śląska

    Science.gov (United States)

    Jonczy, Iwona; Gawor, Łukasz

    2017-06-01

    Characteristics of mining and metallurgical waste dumps in Ruda Śląska was presented in this article. Special attention was paid to the relationship of waste material accumulated on the dumps with resources exploited on studied area. The possibilities of dumps management were also traced and two directions were indicated. The first one is associated with forming a biological covering on the dumps and the second one - with the dumps liquidation and with recovery areas now occupied by the dumps and thus with the secondary use of material collected on them.

  18. Early Iron Age gold buttons from South-Western Iberian Peninsula. Identification of a gold metallurgical workshop

    Directory of Open Access Journals (Sweden)

    Monge Soares, António M.

    2010-12-01

    Full Text Available Early Iron Age gold buttons from Castro dos Ratinhos, Fortios and Outeiro da Cabeça were analysed by conventional EDXRF, Micro-PIXE, SEM-EDS and Optical Microscopy. EDXRF results point out to a rather homogeneous alloy composition throughout all the analysed buttons. PIXE microanalyses show that all the button components (disk, tab and peripheral grooved decorated rod have the same alloy composition. PIXE and SEM-EDS microanalyses, supplemented with optical microscopy characterization, show the absence of chemical composition differences between distinct components and joining zones, suggesting that no solder had been applied, i.e. that a partial melting/solid state diffusion process had been used for the welding of button components. Finally, the noticeable similar compositions together with the use of the same welding process and the very similar artefact typologies suggest that those small gold treasures could be interpreted as the result of the work of a single metallurgical workshop, probably located somewhere in the South-Western Iberian Peninsula.

    Botones de oro pertenecientes a la primera Edad del Hierro, procedentes de Castro dos Ratinhos, Fortios e Outeiro da Cabeça (Portugal, fueron analizados por EDXRF y Micro-PIXE. Los resultados de los análisis por EDXRF mostraron una composición similar en todos los botones, independientemente de su procedencia. Por otra parte, los microanálisis por PIXE permitieron verificar que los componentes soldados de cada botón (disco, presilla y cordón exterior tienen la misma composición química. Además de eso, las áreas de soldadura fueron estudiadas mediante Micro-PIXE, SEM-EDS y posterior análisis metalográfico por microscopia óptica de reflexión. Estos análisis permitieron comprobar la ausencia de soldaduras en las zonas de unión de estos componentes, lo que nos permite concluir que debe haber tenido lugar un proceso de fusión parcial y de difusión en estado sólido para unir

  19. New process for weld metal reliability

    International Nuclear Information System (INIS)

    Hebel, A.G.

    1985-01-01

    The industry-wide nature of weld cracking alerts one to the possibility that there is a fundamental law being overlooked. And in overlooking this law, industry is unable to counteract it. That law mandates that restraint during welding causes internal stress; internal stress causes weld metal to crack. Component restraint during welding, according to the welding standard, is the major cause of weld metal failures. When the metal working industry accepts this fact and begins to counter the effects of restraint, the number of weld failures experienced fall dramatically. Bonal Technologies, inc., of Detroit, has developed the first consistently effective non-thermal process to relieve stress caused by restraint during welding. Bonal's patented Mets-Lax sub-resonant stress relief acts as a restraint neutralizer when used during welding. Meta-Lax weld conditioning produces a finer more uniform weld grain structure. A finer, more uniform grain structure is a clear metallurgical indication of improved mechanical weld properties. Other benefits like less internal stress, and less warpage are also achieved

  20. Investigations of biofilms in the sewerage system of a highly contaminated industrial and mining area for the localization of heavy metal sources. Final report

    International Nuclear Information System (INIS)

    Cichos, C.; Singliar, U.

    1993-02-01

    The high heavy metal loading of the river Freiberger Mulde is largely caused by contaminations arising from the drainage area of the town of Freiberg. The diffuse input from the dewatering surface likely makes an important contribution to this pollution. The elimination of the reasons for the pollutant input into the sewerage and, thus, for the extremely high contamination of the sewage sludges requires a localization of sources and transport ways. For this purpose the method of investigation of biofilms on the sewer surface can be applied as a reliable method. For the industrial and mining area of Freiberg besides the different branches of industry especially the secondary emissions from deposits of old mining and metallurgical plants as well as from the extremely loaded surface of soil play an important role. The investigation of sewerage biofilms in the area considered have shown that the input of nickel and tin into the sewer is mainly caused by industry. Sources of zinc and copper above all are domestic wastewaters, whereas lead is originated from the surface run-off. Especially high pollutions of arsen and cadmium were found obviously arising from mining and production scraps. The results obtained should be the basis of activities for definite interruption of the pollutant input into the sewer system. They are a contribution to the restoration of the hydrographical network of Mulde/Elbe. (orig.) [de

  1. Research on Metallurgical Synthesis.

    Science.gov (United States)

    Aluminum alloys, *Titanium alloys, *Ceramic materials , *Dispersion hardening, *Vapor plating, * Refractory materials , Mechanical properties...Microstructure, Powder alloys, Oxides, Induction heating, Boron alloys, Yttrium oxides, Creep, Fracture(Mechanics), Toughness, Crucibles, Shock waves, Thermomechanics

  2. Heavy metal pollution of soils and sediments at the historical smelting site of the Rudawy Janowickie Mountains (Lower Silesia, Poland).

    Science.gov (United States)

    Kierczak, Jakub; Néel, Catherine; Pietranik, Anna

    2010-05-01

    Multidisciplinary studies of historical slags are mostly focused on exploring how metallurgy evolved through human history. Another purpose for studying historical slags are potentially harmful interactions between slags, surrounding soils, sediments and waters. Metallurgical slags generally concentrate potentially toxic elements (PTE) such as arsenic, copper and lead. These elements may be mobilized and transferred into immediate surroundings. The main aim of our work is to identify factors controlling migration of metals at the historical smelting site of the Rudawy Janowickie Mountains. This study involves detailed analyzes of historical slags (older than 300 years) containing PTE, as well as surrounding soils and sediments. The Rudawy Janowickie Mountains represented an important centre of copper mining and smelting in Poland until 1925 with metallurgical activities being documented as early as in the XIV century. The exploitation of Cu ores has left large amounts of mine tailings and slags extending over ca. 35ha. The slags were deposited on ground and no barriers between the slags and environment were set. Therefore, they were continuously affected by variable factors, for example, changing weather conditions. Soils located in the study area are derived from granitic rocks. They are shallow ( 50 wt. % of coarse fragments). Their pHw is acidic and varies from 3.4 to 4.5 from the topsoil to the deeper horizons in which slags are widespread. Mineral composition of soils and sediments is dominated by quartz, alkali feldspar, plagioclase and biotite. However, some samples may contain additionally numerous slag fragments. At present, the slags occur within three types of environments: (1) at the surface, (2) in soils and (3) in sediments from two streams: Janówka and Smelter Stream. Studied slags were sampled in the vicinity of both streams from (1) surface, (2) soil profiles and (3) streambeds. Furthermore, samples of soils and stream sediments were collected at

  3. ANTIPRODUCTION: PROBLEM OF METAL QUALITY

    Directory of Open Access Journals (Sweden)

    A. G. Anisovich

    2009-01-01

    Full Text Available The most typical examples of defective metallurgical products, presented for analysis to the sector of metallographic and X-ray-structural analysis of FTl NAN of Belarus are examined.

  4. Economic comparison of management modes for contaminated metal scrap

    International Nuclear Information System (INIS)

    Janberg, K.

    1987-01-01

    This report presents an economic study of the three following management modes for contaminated metal scrap: - decontamination of scrap metal followed by release, - direct melting of scrap metal, followed by release or restricted reuse, - super-compaction followed by disposal as radioactive waste. The present study, which refers to conditions prevailing in Germany, includes reviews of the contaminated scrap arisings, of experience with scrap management and of the licensing conditions for metal recycling. The results obtained during the treatment of more than 140 t of contaminated scrap metal show that: - super-compaction is the best procedure for all mixed metallic wastes of small dimensions and complex geometries, as decontamination is very costly in such a case and the melting would lead to undefined metallurgical products; - decontamination is recommendable for simple geometries and activities higher than the regulatory upper limit for melting in an industrial foundry (74 Bq/g); - direct melting for lower activity levels is gaining in competitiveness and has a good chance to be the best solution, in particular when the free use levels will be reduced below the currently accepted levels in Germany

  5. Studies on the influence of metallurgical variables on the stress corrosion behavior of aisi 304 stainless steel in sodium chloride solution using the fracture mechanics approach

    Science.gov (United States)

    Khatak, H. S.; Gnanamoorthy, J. B.; Rodriguez, P.

    1996-05-01

    Stress corrosion data on a nuclear grade AISI type 304 stainless steel in a boiling solution of 5M NaCl+ 0.15M Na2SO4+ 3 mL/L HC1 (bp 381 K) for various metallurgical conditions of the steel are presented in this article. The metallurgical conditions used are solution annealing, sensitization, 10 pct cold work, 20 pct cold work, solution annealing + sensitization, 10 pct cold work + sensi-tization, and 20 pct cold work + sensitization. The fracture mechanics approach has been used to obtain quantitative data on the stress corrosion crack growth rates. The stress intensity factor, K 1, and J integral, J 1, have been used as evaluation parameters. The crack growth rates have been measured using compact tension type samples under both increasing and decreasing stress intensity factors. A crack growth rate of 5 X 10-11 m/s was chosen for the determination of threshold para-meters. Results of the optical microscopic and fractographic examinations are presented. Acoustic signals were recorded during crack growth. Data generated from acoustic emissions, activation energy measurements, and fractographic features indicate hydrogen embrittlement as the possible mechanism of cracking.

  6. El poblado minero-metalúrgico de El Cerro de los Almadenes (Otero de Herreros, Segovia)

    OpenAIRE

    Salas Álvarez, Jesús de la Ascensión; Ayarzagüena Sanz, Mariano; López Cidad, Jesús Fernando; Ramos Sánchez, Francisco; San Clemente Geijo, María del Pilar; Sebastián Reques, Eva; Valiente Cánovas, Santiago; Valle Gutiérrez, Mercedes del

    2014-01-01

    Se analiza en el siguiente trabajo las labores arqueológicas llevadas a cabo en el poblado minero metalúrgico de El Cerro de los Almadenes (Otero de Herreros, Segovia), que ha proporcionado importantes datos para el conocimiento de la explotación del cobre en esta zona desde época protohistórica hasta época medieval Discussed in the following paper archaeological work carried out in the metallurgical mining village of Hill of the Almadenes (Otero de Herreros, Seg...

  7. Study of fatigue crack propagation in laminated metal composites alluminium 1100/alluminium 2024

    International Nuclear Information System (INIS)

    Tavares, R.I.

    1984-01-01

    A study has been made of fatigue crack propagation in laminated metal composites with different volume fraction of constituents. The composites were produced by hot rolling, combining 1100 and 2024 aluminum alloys in crack divider orientation. Mechanical and metallurgical properties of the composites and original alloys sheets have been evaluated. Paris type relationship, corresponding to stage II of fatigue crack propagation curves, has been determined by two different methods, wich have shown to be equivalent. A computer software in FORTRAN language was developed for all the mathematical manipulation of fatigue data including statistical analysis and graphics. (Author) [pt

  8. Recovery concept of value metals from automotive lithium-ion batteries

    International Nuclear Information System (INIS)

    Traeger, Thomas; Friedrich, Bernd

    2015-01-01

    A recycling process for automotive lithium-ion batteries was developed. The process combines a mechanical pretreatment with pyrometallurgical recycling process step to recover all battery components, and realize cost-neutral and sustainable recycling. The focus of the research work is the development of a pyrometallurgical process step to recover especially Li out of electrode mass powder which is the fine fraction extracted mechanically from spent Li-ion batteries. Two metallurgical treatment technologies were investigated: direct vacuum evaporation of Li and recovery of metallic Li by distillation, and a selective entraining gas evaporation of Li and recovery of lithium oxide.

  9. New metals

    International Nuclear Information System (INIS)

    Bergqvist, U.

    1983-12-01

    The aim of this report is to estimate the exposure to various metals and metal compounds and discuss the available information of the possible toxic effects of these metals and compounds. In the first section, some metals are defined as those with either a large or a fast increasing exposure to living organisms. The available information on toxicity is discussed in the second section. In the third section interesting metals are defined as compounds having a large exposure and an apparent insufficient knowledge of their possible toxic effects. Comments on each of these metals are also to be found in the third section. (G.B.)

  10. A unified dislocation density-dependent physical-based constitutive model for cold metal forming

    Science.gov (United States)

    Schacht, K.; Motaman, A. H.; Prahl, U.; Bleck, W.

    2017-10-01

    Dislocation-density-dependent physical-based constitutive models of metal plasticity while are computationally efficient and history-dependent, can accurately account for varying process parameters such as strain, strain rate and temperature; different loading modes such as continuous deformation, creep and relaxation; microscopic metallurgical processes; and varying chemical composition within an alloy family. Since these models are founded on essential phenomena dominating the deformation, they have a larger range of usability and validity. Also, they are suitable for manufacturing chain simulations since they can efficiently compute the cumulative effect of the various manufacturing processes by following the material state through the entire manufacturing chain and also interpass periods and give a realistic prediction of the material behavior and final product properties. In the physical-based constitutive model of cold metal plasticity introduced in this study, physical processes influencing cold and warm plastic deformation in polycrystalline metals are described using physical/metallurgical internal variables such as dislocation density and effective grain size. The evolution of these internal variables are calculated using adequate equations that describe the physical processes dominating the material behavior during cold plastic deformation. For validation, the model is numerically implemented in general implicit isotropic elasto-viscoplasticity algorithm as a user-defined material subroutine (UMAT) in ABAQUS/Standard and used for finite element simulation of upsetting tests and a complete cold forging cycle of case hardenable MnCr steel family.

  11. Spatiotemporal dynamics of the pollution of Al-Fe-humus podzols in the impact zone of a nonferrous metallurgical plant

    Science.gov (United States)

    Lyanguzova, I. V.; Goldvirt, D. K.; Fadeeva, I. K.

    2016-10-01

    The dependence of the level of contamination of the upper horizon of Al-Fe-humus podzols (Podzols Rustic) with heavy metals (Ni, Cu) on the distance from the Severonickel smelter (Monchegorsk, Murmansk oblast) was studied on a number of test plots in the medium-aged pine stands. It was found that metal concentrations in the soils could be reasonably approximated by the negative exponential function. In the buffer zone of the smelter, the concentrations of Ni and Cu exceed background values by 8-17 times; in the impact zone, by 50-100 times. The study of the dynamics of acid-soluble forms of Ni and Cu in the organic horizons of podzols on the key plots showed that the boundaries of polluted territory shift towards background regions despite the recent five-eightfold decrease in the emissions. The concentrations of heavy metals in the litter horizons continued to increase in the buffer zone. In the impact zone, their contamination remained at the very high level. Firm bounding of heavy metals in the organic horizon coupled with their continuing aerial input did not allow the beginning of the soil self-purification process, which might last for decades and centuries. Raster electron microscope and X-ray spectral microanalysis showed that particles (>85%) of the ashed matter of organic horizons from the background region, the buffer zone, and the impact zone is mainly represented by various soil-forming minerals and iron oxides (in particular, magnetite). In the samples from the impact zone, about 5% of the mineral particles had the surface morphology and chemical composition typical of dust particles emitted into the air by metal smelters. Most probably, these spherical particles represented magnetite Fe3O4 enriched in heavy metals (Cu, Ni).

  12. Metal lagging

    International Nuclear Information System (INIS)

    Lemercier, Guy.

    1974-01-01

    The metal lagging described is characterized by the fact that it is formed of closed sacks composed of an elastic metal mass, compressed in an outer envelope made of a fine mesh metal fabric. The metal mass is composed of stainless steel wool stuffed into the envelope. This lagging is particularly intended for the thermal protection of the end slab of LMFBR type reactors [fr

  13. Liquid-metal flows and magnetohydrodynamics. Beersheba International Seminar on Magnetohydrodynamic Flows and Turbulence, 3rd, University of the Negev, Beersheba, Israel, March 23-27, 1981, technical papers

    International Nuclear Information System (INIS)

    Branover, H.; Lykoudis, P.S.; Yakhot, A.

    1983-01-01

    The papers contained in this volume provide an overview of the present status of studies in liquid-metal MHD flows, including some related problems of MHD of a general kind and different applications of these flows. The topics discussed include fundamental studies in MHD and turbulence MHD generation and electromagnetic flowmeters electromagnetic pumps, flow couplers, fission and fusion applications and metallurgical magnetohydrodynamics. Papers are presented on a finite-element analysis of two-dimensional MHD flows, electromagnetic stirring in the coreless induction furnace, liquid-solid separation in a molten metal by a stationary electromagnetic field, and magnetic levitation of liquid metals. No individual items are abstracted in this volume

  14. Silicone metalization

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

    2008-12-09

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  15. Metals and Neurodegeneration

    Science.gov (United States)

    Chen, Pan; Miah, Mahfuzur Rahman; Aschner, Michael

    2016-01-01

    Metals play important roles in the human body, maintaining cell structure and regulating gene expression, neurotransmission, and antioxidant response, to name a few. However, excessive metal accumulation in the nervous system may be toxic, inducing oxidative stress, disrupting mitochondrial function, and impairing the activity of numerous enzymes. Damage caused by metal accumulation may result in permanent injuries, including severe neurological disorders. Epidemiological and clinical studies have shown a strong correlation between aberrant metal exposure and a number of neurological diseases, including Alzheimer’s disease, amyotrophic lateral sclerosis, autism spectrum disorders, Guillain–Barré disease, Gulf War syndrome, Huntington’s disease, multiple sclerosis, Parkinson’s disease, and Wilson’s disease. Here, we briefly survey the literature relating to the role of metals in neurodegeneration. PMID:27006759

  16. Human exposure to metals due to consumption of fish from an artificial lake basin close to an active mining area in Katanga (D.R. Congo)

    Energy Technology Data Exchange (ETDEWEB)

    Squadrone, S., E-mail: stefania.squadrone@izsto.it [Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d' Aosta, via Bologna 148, 10154 Torino (Italy); Burioli, E.; Monaco, G. [Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d' Aosta, via Bologna 148, 10154 Torino (Italy); Koya, M.K. [Institut Supérieur d' Etudes Agronomiques (ISEA) de Kaseya/Kongolo (Congo, The Democratic Republic of the); Prearo, M.; Gennero, S. [Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d' Aosta, via Bologna 148, 10154 Torino (Italy); Dominici, A. [Independent Veterinarian Researcher, Turin (Italy); Abete, M.C. [Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d' Aosta, via Bologna 148, 10154 Torino (Italy)

    2016-10-15

    The concentrations of 14 essential and nonessential trace elements were determined in fish from Lake Tshangalele, Katanga province, Democratic Republic of Congo. This province has been a place of intensive mining activities for centuries, which have increased in recent years, due to the use of metals such as copper and cobalt for the industries of fast-growing countries. Lake Tshangalele, which receives effluents from metallurgical and mining plants in Likasi, is home to several fish species that are an important part of the diet of the local population, and, therefore, it constitutes a relevant site for documenting the human exposure to metals as a result of a fish diet. The highest concentrations (median levels, dry weight) of cobalt (7.25 mg kg{sup −} {sup 1}), copper (88.1 mg kg{sup −} {sup 1}), iron (197.5 mg kg{sup −} {sup 1}), manganese (65.35 mg kg{sup −} {sup 1}), zinc (122.9 mg kg{sup −} {sup 1}) and aluminum (135.4 mg kg{sup −} {sup 1}) were found in fish collected closest to the copper mining plant, with decreasing concentrations along the lake, up to the dam. In the most contaminated fish samples, values of up to 270.1 mg kg{sup −} {sup 1} for Al, 173.1 mg kg{sup −} {sup 1} for Cu, 220.9 mg kg{sup −} {sup 1} for Zn, 211.0 mg kg{sup −} {sup 1} for Mn, 324.2 mg kg{sup −} {sup 1} for Fe, 15.1 mg kg{sup −} {sup 1} for Co, 4.2 mg kg{sup −} {sup 1} for Cr, 1.6 mg kg{sup −} {sup 1} for Cd, 1.9 mg kg{sup −} {sup 1} for Pb, and 1.8 mg kg{sup −} {sup 1} for Ni were found. Metal contamination from mining activity resulted in being of great concern because of potential health risks to the local inhabitants due to the consumption of heavily contaminated fish. Capsule: High levels of metals, especially cobalt, aluminum, iron, manganese, zinc and cadmium were found in fish from Tshangalele water system. - Highlights: • Metal contamination from mining activity is of great concern for human exposure. • We analyzed metal content in

  17. Development of dissimilar metal transition joint by hot roll bonding technique

    International Nuclear Information System (INIS)

    Nagai, Takayuki; Takeda, Seiichiro; Tanaka, Yasumasa; Ogawa, Kazuhiro; Nakasuji, Kazuyuki; Ikenaga, Yoshiaki.

    1994-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) with stainless steel piping is needed for nuclear fuel reprocessing plants. The authors have developed dissimilar metal transition joints between stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot roll bonding process, using the newly developed mill called 'rotary reduction mill'. In the R and D program, appropriate bonding conditions in the manufacturing process of the joints were established. This report presents the structure of transition joints and the manufacturing process by the hot roll bonding technique. Then, the evaluation of mechanical and corrosion properties and the results of demonstration test of joints for practical use are described. (author)

  18. Development of dissimilar metal transition joint by hot roll bonding technique

    International Nuclear Information System (INIS)

    Nagai, Takayuki; Takeuchi, Masayuki; Takeda, Seiichiro; Shikakura, Sakae; Ogawa, Kazuhiro; Nakasuji, Kazuyuki; Kajimura, Haruhiko.

    1995-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) with stainless steel piping is needed for nuclear fuel reprocessing plants. The authors have developed dissimilar metal transition joints between stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot roll bonding process, using the newly developed mill called 'rotary reduction mill'. In the R and D program, appropriate bonding conditions in the manufacturing process of the joints were established. This report presents the structure of transition joints and the manufacturing process by hot roll bonding technique. Then, the evaluation of mechanical and corrosion properties and the results of demonstration test of joints for practical use are described. (author)

  19. 1Q/2Q00 M-Area and Metallurgical Laboratory Hazardous Waste Management Facilities Groundwater Monitoring and Corrective-Action Report - First and Second Quarters 2000 - Volumes I, II, and II

    Energy Technology Data Exchange (ETDEWEB)

    Chase, J.

    2000-10-24

    This report describes the groundwater monitoring and corrective-action program at the M-Area Hazardous Waste Management Facility (HWMF) and the Metallurgical Laboratory (Met Lab) HWMF at the Savannah River site (SRS) during first and second quarters of 2000.

  20. Microstructure of Precipitation Hardenable Powder Metallurgical Ni Alloys Containing 35 to 45 pct Cr and 3.5 to 6 pct Nb

    DEFF Research Database (Denmark)

    Bihlet, Uffe Ditlev; Dahl, Kristian Vinter; Somers, Marcel A. J.

    2014-01-01

    Ni-based alloys with high Cr contents are not only known for their excellent high temperature and hot corrosion resistance, but are also known for poor mechanical properties and difficult workability. Powder metallurgical (PM) manufacturing of alloys may overcome several of the shortcomings...... encountered in materials manufacturing involving solidification. In the present work, six PM Ni-based alloys containing 35 to 45 wt pct Cr and 3.5 to 6 wt pct Nb were produced and compacted via hot isostatic pressing. Samples were heat treated for up to 1656 hours at either 923 K or 973 K (650 °C or 700 °C......), and the microstructures and mechanical properties were quantified and compared to thermodynamic calculations. For the majority of the investigated alloys, the high Cr and Nb contents caused development of primary populations of globular α-Cr and δ (Ni3Nb). Transmission electron microscopy of selected alloys confirmed...