High Purity Tungsten Spherical Particle Preparation From WC-Co Spent Hard Scrap

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Han Chulwoong

2015-06-01

Full Text Available Tungsten carbide-cobalt hard metal scrap was recycled to obtain high purity spherical tungsten powder by a combined hydrometallurgy and physical metallurgy pathway. Selective leaching of tungsten element from hard metal scrap occurs at solid / liquid interface and therefore enlargement of effective surface area is advantageous. Linear oxidation behavior of Tungsten carbide-cobalt and the oxidized scrap is friable to be pulverized by milling process. In this regard, isothermally oxidized Tungsten carbide-cobalt hard metal scrap was mechanically broken into particles and then tungsten trioxide particle was recovered by hydrometallurgical method. Recovered tungsten trioxide was reduced to tungsten particle in a hydrogen environment. After that, tungsten particle was melted and solidified to make a spherical one by RF (Ratio Frequency thermal plasma process. Well spherical tungsten micro-particle was successfully obtained from spent scrap. In addition to the morphological change, thermal plasma process showed an advantage for the purification of feedstock particle.

Inhibitory Effect of Waste Glass Powder on ASR Expansion Induced by Waste Glass Aggregate

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Shuhua Liu

2015-10-01

Full Text Available Detailed research is carried out to ascertain the inhibitory effect of waste glass powder (WGP on alkali-silica reaction (ASR expansion induced by waste glass aggregate in this paper. The alkali reactivity of waste glass aggregate is examined by two methods in accordance with the China Test Code SL352-2006. The potential of WGP to control the ASR expansion is determined in terms of mean diameter, specific surface area, content of WGP and curing temperature. Two mathematical models are developed to estimate the inhibitory efficiency of WGP. These studies show that there is ASR risk with an ASR expansion rate over 0.2% when the sand contains more than 30% glass aggregate. However, WGP can effectively control the ASR expansion and inhibit the expansion rate induced by the glass aggregate to be under 0.1%. The two mathematical models have good simulation results, which can be used to evaluate the inhibitory effect of WGP on ASR risk.

Bioactivity and cell proliferation in radiopaque gel-derived CaO-P2O5-SiO2-ZrO2 glass and glass-ceramic powders.

Science.gov (United States)

Montazerian, Maziar; Yekta, Bijan Eftekhari; Marghussian, Vahak Kaspari; Bellani, Caroline Faria; Siqueira, Renato Luiz; Zanotto, Edgar Dutra

2015-10-01

In this study, 10 mol% ZrO2 was added to a 27CaO-5P2O5-68SiO2 (mol%) base composition synthesized via a simple sol-gel method. This composition is similar to that of a frequently investigated bioactive gel-glass. The effects of ZrO2 on the in vitro bioactivity and MG-63 cell proliferation of the glass and its derivative polycrystalline (glass-ceramic) powder were investigated. The samples were characterized using thermo-gravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled to energy dispersive X-ray spectroscopy (EDS). Release of Si, Ca, P and Zr into simulated body fluid (SBF) was determined by inductively coupled plasma (ICP). Upon heat treatment at 1000 °C, the glass powder crystallized into an apatite-wollastonite-zirconia glass-ceramic powder. Hydroxycarbonate apatite (HCA) formation on the surface of the glass and glass-ceramic particles containing ZrO2 was confirmed by FTIR and SEM. Addition of ZrO2 to the base glass composition decreased the rate of HCA formation in vitro from one day to three days, and hence, ZrO2 could be employed to control the rate of apatite formation. However, the rate of HCA formation on the glass-ceramic powder containing ZrO2 crystal was equal to that in the base glassy powder. Tests with a cultured human osteoblast-like MG-63 cells revealed that the glass and glass-ceramic materials stimulated cell proliferation, indicating that they are biocompatible and are not cytotoxic in vitro. Moreover, zirconia clearly increased osteoblast proliferation over that of the Zr-free samples. This increase is likely associated with the lower solubility of these samples and, consequently, a smaller variation in the media pH. Despite the low solubility of these materials, bioactivity was maintained, indicating that these glassy and polycrystalline powders are potential candidates for bone graft substitutes and bone cements with

Effect of Acid Dissolution Conditions on Recovery of Valuable Metals from Used Plasma Display Panel Scrap

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Kim Chan-Mi

2017-06-01

Full Text Available The objective of this particular study was to recover valuable metals from waste plasma display panels using high energy ball milling with subsequent acid dissolution. Dissolution of milled (PDP powder was studied in HCl, HNO3, and H2SO4 acidic solutions. The effects of dissolution acid, temperature, time, and PDP scrap powder to acid ratio on the leaching process were investigated and the most favorable conditions were found: (1 valuable metals (In, Ag, Mg were recovered from PDP powder in a mixture of concentrated hydrochloric acid (HCl:H2O = 50:50; (2 the optimal dissolution temperature and time for the valuable metals were found to be 60°C and 30 min, respectively; (3 the ideal PDP scrap powder to acid solution ratio was found to be 1:10. The proposed method was applied to the recovery of magnesium, silver, and indium with satisfactory results.

The effect of intermediate stop and ball size in fabrication of recycled steel powder using ball milling from machining steel chips

International Nuclear Information System (INIS)

Fitri, M.W.M.; Shun, C.H.; Rizam, S.S.; Shamsul, J.B.

2007-01-01

A feasibility study for producing recycled steel powder from steel scrap by ball milling was carried out. Steel scrap from machining was used as a raw material and was milled using planetary ball milling. Three samples were prepared in order to study the effect of intermediate stop and ball size. Sample with intermediate stop during milling process showed finer particle size compared to the sample with continuous milling. Decrease in the temperature of the vial during the intermediate stop milling gives less ductile behaviour to the steel powder, which is then easily work-hardened and fragmented to fine powder. Mixed small and big size ball give the best production of recycled steel powder where it gives higher impact force to the scrap and accelerate the fragmentation of the steel scrap into powder. (author)

Characteristics of Indium Tin Oxide (ITO Nanoparticles Recovered by Lift-off Method from TFT-LCD Panel Scraps

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Dongchul Choi

2014-11-01

Full Text Available In this study, indium-tin-oxide (ITO nanoparticles were simply recovered from the thin film transistor-liquid crystal display (TFT-LCD panel scraps by means of lift-off method. This can be done by dissolving color filter (CF layer which is located between ITO layer and glass substrate. In this way the ITO layer was easily lifted off the glass substrate of the panel scrap without panel crushing. Over 90% of the ITO on the TFT-LCD panel was recovered by using this method. After separating, the ITO was obtained as particle form and their characteristics were investigated. The recovered product appeared as aggregates of particles less than 100 nm in size. The weight ratio of In/Sn is very close to 91/9. XRD analysis showed that the ITO nanoparticles have well crystallized structures with (222 preferred orientation even after recovery. The method described in this paper could be applied to the industrial recovery business for large size LCD scraps from TV easily without crushing the glass substrate.

COMPARATIVE ASSESSMENT OF RICE HUSK ASH, POWDERED GLASS AND CEMENT AS LATERITIC SOIL STABILIZERS

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Adebisi Ridwan

2016-10-01

Full Text Available This paper compares the stabilizing effects of three different materials, namely: rice husk ash, powdered glass, and cement on the properties of lateritic soil. The basic properties of the lateritic soil were first obtained through colour, moisture content determination, specific gravity, particle size distribution and Atterberg limits tests. Each of the stabilizing materials was then mixed with the lateritic soil in varying percentages of 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by weight of the soil. Thereafter, compaction and California bearing ratio (CBR tests were carried out on the sample mixes to determine the effects of the materials on the lateritic soil. Chemical tests were also carried out on the samples to determine their percentage oxides composition. The compaction test showed that the highest maximum dry densities (MDD obtained for the mixed samples were 2.32 g/cm3 (at 2.5% cement addition, 2.28g/cm3 (at 5% powdered glass (PG addition and 2.18 g/cm3 (at 5% rice husk ash (RHA addition with corresponding optimum moisture contents (OMC of 10.06%, 14.3% and 12.31% respectively. The CBR tests showed that the CBR values increased in all cases as the materials were added with those of the cement and powdered glass giving the highest values and showing close semblance under unsoaked conditions. The chemical test showed that the significant oxides present in the cement, powdered glass and rice husk ash were CaO (53.60%, SiO2 (68.45% and SiO2 (89.84% respectively.

In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

Science.gov (United States)

Prabhu, M.; Ruby Priscilla, S.; Kavitha, K.; Manivasakan, P.; Rajendran, V.; Kulandaivelu, P.

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. PMID:25276834

In vitro bioactivity and antimicrobial tuning of bioactive glass nanoparticles added with neem (Azadirachta indica) leaf powder.

Science.gov (United States)

Prabhu, M; Ruby Priscilla, S; Kavitha, K; Manivasakan, P; Rajendran, V; Kulandaivelu, P

2014-01-01

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

Process for removing and detoxifying cadmium from scrap metal including mixed waste

International Nuclear Information System (INIS)

Kronberg, J.W.

1994-01-01

Cadmium-bearing scrap from nuclear applications, such as neutron shielding and reactor control and safety rods, must usually be handled as mixed waste since it is radioactive and the cadmium in it is both leachable and highly toxic. Removing the cadmium from this scrap, and converting it to a nonleachable and minimally radioactive form, would greatly simplify disposal or recycling. A process now under development will do this by shredding the scrap; leaching it with reagents which selectively dissolve out the cadmium; reprecipitating the cadmium as its highly insoluble sulfide; then fusing the sulfide into a glassy matrix to bring its leachability below EPA limits before disposal. Alternatively, the cadmium may be recovered for reuse. A particular advantage of the process is that all reagents (except the glass frit) can easily be recovered and reused in a nearly closed cycle, minimizing the risk of radioactive release. The process does not harm common metals such as aluminum, iron and stainless steel, and is also applicable to non-nuclear cadmium-bearing scrap such as nickel-cadmium batteries

Recycled tetrahedron-like CuCl from waste Cu scraps for lithium ion battery anode.

Science.gov (United States)

Hou, Hongying; Yao, Yuan; Liu, Song; Duan, Jixiang; Liao, Qishu; Yu, Chengyi; Li, Dongdong; Dai, Zhipeng

2017-07-01

The wide applications of metal Cu inevitably resulted in a large quantity of waste Cu materials. In order to recover the useful Cu under the mild conditions and reduce the environmental emission, waste Cu scraps were recycled in the form of CuCl powders with high economic value added (EVA) via the facile hydrothermal route. The recycled CuCl powders were characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results suggested that the recycled CuCl powders consisted of many regular tetrahedron-like micro-particles. Furthermore, in order to reduce the cost of lithium ion battery (LIB) anode and build the connection of waste Cu scraps and LIB, the recycled CuCl powders were evaluated as the anode active material of LIB. As expected, the reversible discharge capacity was about 171.8mAh/g at 2.0C even after 50 cycles, implying the satisfactory cycle stability. Clearly, the satisfactory results may open a new avenue to develop the circular economy and the sustainable energy industry, which would be very important in terms of both the resource recovery and the environmental protection. Copyright © 2017. Published by Elsevier Ltd.

Crystallization behaviour and thermal stability of two aluminium-based metallic glass powder materials

Energy Technology Data Exchange (ETDEWEB)

Li, X.P.; Yan, M. [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia); Yang, B.J. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, J.Q., E-mail: jqwang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Schaffer, G.B. [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia); Qian, M., E-mail: ma.qian@uq.edu.au [University of Queensland, School of Mechanical and Mining Engineering, ARC Centre of Excellence for Design in Light Metals, Brisbane, QLD 4072 (Australia)

2011-12-15

Highlights: Black-Right-Pointing-Pointer The crystallization paths and products of Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder have been identified. Black-Right-Pointing-Pointer The thermal stability of Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder has been assessed. Black-Right-Pointing-Pointer The Al{sub 86}Ni{sub 7}Y{sub 4.5}Co{sub 1}La{sub 1.5} powder shows a wide processing window of 75 K. Black-Right-Pointing-Pointer The powder has the potential to be consolidated into thick BMG components based on the findings. Black-Right-Pointing-Pointer The Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} powder shows similar characteristics but inferior thermal stability. - Abstract: The crystallization behaviour and thermal stability of two Al-based metallic glass powder materials, Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} and Al{sub 86}Ni{sub 6}Y{sub 4.5}Co{sub 2}La{sub 1.5}, have been investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and electron microscopy. Both alloy powders show a distinct three-stage crystallization process with a similar gap of {approx}75 K between the onset crystallization temperature (T{sub x}) and the second crystallization temperature. Crystallization occurs by the precipitation and growth of fcc-Al, without intermetallic formation. The apparent activation energy for each stage of crystallization was determined from DSC analyses and the phases resulting from each crystallization stage were identified by XRD and electron microscopy. The critical cooling rate for each alloy powder was calculated from the DSC data. These results are necessary to inform the consolidation of amorphous powder particles of Al{sub 85}Ni{sub 5}Y{sub 6}Co{sub 2}Fe{sub 2} or Al{sub 86}Ni{sub 6}Y{sub 4.5}Co{sub 2}La{sub 1.5} into thick (>1 mm) metallic glass components.

LSA glass-ceramic tiles made by powder pressing; Obtencao de placas vitroceramicas do sistema LSA utilizando a prensagem de pos

Energy Technology Data Exchange (ETDEWEB)

Figueira, F.C.; Bertan, F.M. [Colorminas Colorificio e Mineracao, Icara, SC (Brazil); Riella, H.G. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Programa de Pos-Graduaco em Engenharia Quimica; Uggioni, E. [Universidade do Extremo Sul Catarinense (UFSC), Florianopolis, SC (Brazil). Curso de Engenharia de Materiais; Bernardin, A.M., E-mail: amb@unesc.ne [Servico Nacional de Aprendizagem Industrial (SENAI), Tijucas, SC (Brazil). Dept. de Tecnologia em Ceramica

2009-07-01

A low cost alternative for the production of glass-ceramic materials is the pressing of the matrix glass powders and its consolidation simultaneously with crystallization in a single stage of sintering. The main objective of this work was to obtain LSA glass ceramics with low thermal expansion, processed by pressing and sintering a ceramic frit powder. The raw materials were homogenized and melted (1480 deg C, 80min), and the melt was poured in water. The glass was chemically (XRF and AAS) and thermally (DTA, 10 deg C/min, air) characterized, and then ground (60min and 120min). The ground powders were characterized (laser diffraction) and compressed (35MPa and 45MPa), thus forming four systems. The compacts were dried (150 deg C, 24h) and sintered (1175 deg C and 1185 deg C, 10 deg C/min). Finally, the glass-ceramics were characterized by microstructural analysis (SEM and XRD), mechanical behavior ({sigma}bending) and thermal analysis ({alpha}). The best results for thermal expansion were those for the glass-ceramics processed with smaller particle size and greater compaction pressure. (author)

Cesium Hydroxide Fusion Dissolution of Analytical Reference Glass-1 in Both Powder and Shard Form

International Nuclear Information System (INIS)

Coleman, C.J.; Spencer, W.A.

1998-04-01

CsOH has been shown to be an effective and convenient dissolution reagent for Analytical Reference Glass-1 (ARG-1). This glass standard was prepared from nonradioactive DWPF Start-up Glass. Therefore, its composition is similar to DWPF product glass and many of the glass matrices prepared at SRTC.The principal advantage of the CsOH fusion dissolution is that the reagent does not add the alkali metals Li, Na, and K usually needed by SRS customers. Commercially available CsOH is quite pure so that alkali metals can be measured accurately, often without blank corrections. CsOH fusions provide a single dissolution method for applicable glass to replace multiple dissolution schemes used by most laboratories. For example, SRTC glass samples are most commonly dissolved with a Na 2 O 2 -NaOH fusion (ref.1) and a microwave- assisted acid dissolution with HNO 3 -HF-H 3 BO 3 -HCl (ref.2). Othe laboratories use fusion methods based on KOH, LiBO 2 , and Na 2 CO 3 CsOH fusion approach reduces by half not only the work in the dissolution laboratory, but also in the spectroscopy laboratories that must analyze each solution.Experiments also revealed that glass shards or pellets are rapidly attacked if the flux temperature is raised considerably above the glass softening point. The softening point of ARG-1 glass is near 650 degrees C. Fusions performed at 750 degrees C provided complete dissolutions and accurate elemental analyses of shards. Successful dissolution of glass shards was demonstrated with CsOH, Na 2 O 2 , NaOH, KOH, and RbOH. Ability to dissolve glass shards is of considerable practical importance. Crushing glass to a fine powder is a slow and tedious task, especially for radioactive glasses dissolved in shielded cells. CsOH fusion of glass powder or shards is a convenient, cost-effective dissolution scheme applicable in SRTC, the DWPF, and the commercial glass industry

High ion-exchange properties of hybrid materials from X-type zeolite and ground glass powder

Science.gov (United States)

Taira, Nobuyuki; Yoshida, Kohei

2017-10-01

Zeolites are crystalline aluminosilicates with a homogeneous distribution of micropores with a superior cation-exchange capacity. Because they have especially excellent selective exchange properties, a considerable number of studies have been conducted on treating water containing radioisotopes using the zeolites. When using artificial zeolites, they have inferior sinterability; in addition, it is quite hard for them to remove from polluted liquid since these artificial zeolites are principally synthesized as a form of powder, which is a disadvantage. In this study, hybrid materials were prepared from X-type zeolite and waste glass powder. Their ion-removal effect and mechanical strength were investigated. The zeolite and waste glass were ground in an agate mortar in several ratios. 0.5 g of the mixture was pressure-molded into pellets having a diameter of 7 mm. These pellets were slowly heated at the speed of 240°C/h to 700°C and maintained at 700°C for 2 h. The removal rate of Sr2+ ions increased as the amount of X-type zeolite in the hybrid materials increased; the former increased up to 100% when the content of latter exceeded 50%. The mechanical strength increased by increasing the amount of glass in the hybrid materials. This is attributed to the fact that the glass powder acts as a binder that improves the densification and consequently the mechanical strength of the hybrid materials.

The mechanical and thermal characteristics of phenolic foam reinforced with kaolin powder and glass fiber fabric

Science.gov (United States)

Xiao, Wenya; Huang, Zhixiong; Ding, Jie

2017-12-01

In this work, kaolin powder and glass fiber fabric were added to PF in order to improve its thermal stability and mechanical property. Micro-structures of carbonized PF with kaolin powder were inspected by scanning electron microscopy (SEM) to demonstrate the filler’s pinning effect. SEM results illustrated modified PF had well morphology after high-temperature heat treatment. The Fourier transform infrared spectrometer (FTIR) test was carried out and found that kaolin powder only physically dispersed in PF. The compression test and thermal weight loss test were done on two groups of modified PF (Group A: add powder and fabric; Group B: add powder only). Results showed that all modified PF were better than pure PF, while foams with powder and fabric showed better mechanical characteristic and thermal stability compared with foams with powder only.

Spectrophotometric study of bio-sorption of uranium on glass grade spodumene shell powder

International Nuclear Information System (INIS)

Parakudyil, A.S.; Pillai, A.K.; Reddy, A.V.R.; Singal, R.K.; Sharma, P.K.; Michael, K.M.

2012-01-01

Separation of uranium found in iron ore leachates was done by extraction chromatography using glass grade spodumene shellpowder (GSS) in nitric acid medium and analyzed spectrophotometrically. The influences of metal ion concentration, pH and adsorption capacity of biomass were investigated. Biosorption is a potential method of separation of heavy and trace metals from waste water and effluents from various sources. The adsorption capacities of biomass were investigated by batch experiments and column experiments. In the present study, glass grade spodumene shell powder (GSS) in acidic medium is being used as a biosorbent

Influence of bone porcelain scraps on the physical characteristics and phase composition of a hard porcelain body

Energy Technology Data Exchange (ETDEWEB)

Nodeh, A.A.

2017-07-01

Hard porcelain is constituted in the alkali oxides-alumina-silica ternary system, and produced by a mixture of clay-feldspar and silica. The most important properties of this porcelain are high mechanical strength, translucency and whiteness. These properties depend on quality of raw material, firing temperature and soaking time. In bone porcelain bone ash was added to body composition up to 50wt.%. Generally hard porcelain and bone porcelain scrap cannot be reused in body composition. Whereas using these scrap could help natural resources. In this research using bon porcelain scraps in hard porcelain body have been investigated. Results show, this substitution decrease firing temperature, linear expansion and increase glass, probability of deformation and total shrinkage. Using 6wt.% bone porcelain scraps to hard porcelain body composition besides improving some properties, increases 1340°C firing mechanical strength two times and helps natural resources. (Author)

Influence of Waste Glass Powder Addition on the Pore Structure and Service Properties of Cement Mortars

Directory of Open Access Journals (Sweden)

José Marcos Ortega

2018-03-01

Full Text Available At present, reusing waste constitutes an important challenge in order to reach a more sustainable environment. The cement industry is an important pollutant industrial sector. Therefore, the reduction of its CO2 emissions is now a popular topic of study. One way to lessen those emissions is partially replacing clinker with other materials. In this regard, the reuse of waste glass powder as a clinker replacement could be possible. This is a non-biodegradable residue that permanently occupies a large amount of space in dumping sites. The aim of this work is to study the long-term effects (400 days of the addition of waste glass powder on the microstructure and service properties of mortars that incorporate up to 20% of this addition as clinker replacement. The microstructure has been characterised using the non-destructive impedance spectroscopy technique and mercury intrusion porosimetry. Furthermore, differential thermal analysis was also performed. Compressive strength and both steady-state and non-steady-state chloride diffusion coefficients have also been determined. Considering the obtained results, mortars with 10% and 20% waste glass powder showed good service properties until 400 days, similar to or even better than those made with ordinary Portland cement without additions, with the added value of contributing to sustainability.

Bioactivity of gel-glass powders in the CaO-SiO2 system: a comparison with ternary (CaO-P2O5-SiO2) and quaternary glasses (SiO2-CaO-P2O5-Na2O).

Science.gov (United States)

Saravanapavan, Priya; Jones, Julian R; Pryce, Russell S; Hench, Larry L

2003-07-01

Bioactive glasses react chemically with body fluids in a manner that is compatible with the repair processes of the tissues. This results in the formation of an interfacial bond between the glasses and living tissue. Bioactive glasses also stimulate bone-cell proliferation. This behavior is dependent on the chemical composition as well as the surface texture of the glasses. It has been recently reported that gel-derived monolith specimens in the binary SiO2 - CaO are bioactive over a similar molar range of SiO2 content as the previously studied ternary CaO-P2O5-SiO2 system. In this report, the preparation and bioactivity of the binary gel-glass powder with 70 mol % SiO2 is discussed and its bioactivity is compared with the melt-derived 45S5 (quaternary) Bioglass and sol-gel-derived 58S (ternary) bioactive gel-glass compositions. Dissolution kinetic parameters K(1) and K(2) were also computed based on the silicon release for all glass powders. It was shown that the simple two-component SiO2-CaO gel-glass powder is bioactive with comparable dissolution rates as the clinically used melt-derived 45S5 Bioglass powder and extensively studied sol-gel-derived 58S gel-glass powder. Copyright 2003 Wiley Periodicals, Inc.

Issues in recycling galvanized scrap

Energy Technology Data Exchange (ETDEWEB)

Koros, P.J. [LTV Steel Co., Inc., Cleveland, OH (United States); Hellickson, D.A. [General Motors Corp., Detroit, MI (United States); Dudek, F.J. [Argonne National Lab., IL (United States)

1995-02-10

The quality of the steel used for most galvanizing (and tinplate) applications makes scrap derived from their production and use a premier solid charge material for steelmaking. In 1989 the AISI created a Task Force to define the issues and to recommend technologically and economically sound approaches to assure continued, unhindered recyclability of the growing volume of galvanized scrap. The AISI program addressed the treatment of full-sized industrial bales of scrap. The current, on-going MRI (US)--Argonne National Laboratory program is focused on ``loose`` scrap from industrial and post-consumer sources. Results from these programs, issues of scrap management from source to steel melting, the choices for handling zinc in iron and steelmaking and the benefits/costs for removal of zinc (and lead) from scrap prior to melting in BOF and foundry operations are reviewed in this paper.

Fabrication and evaluation of hybrid materials from A-zeolite and ground glass powders for vitrified radioactive waste

International Nuclear Information System (INIS)

Kamitani, Masataka; Kondo, Mitsunori; Hiki, Tomonori; Tagami, Toru; Nakahira, Atsushi; Wakihara, Toru

2014-01-01

The samples from A-type zeolite and ground soda-lime glass powders were solidified by calcinations at 600 to 800°C in air atmosphere. These hybrid zeolite/glass samples at 700°C were in part insufficiently densified and hybrid samples were fully densified at 800°C, although the densification was not generated at 600°C. A-zeolites were still stable in glass melt at 800°C for hybrid zeolite/glass samples. These hybrid zeolite/glass samples had the ion exchange ability of 20% against Sr 2+ and the high ability over 80% against Cs + as well as A-zeolite. Microstructures of obtained hybrid zeolite/glass samples were evaluated. (author)

Effect of different glasses in glass bonded zeolite

International Nuclear Information System (INIS)

Lewis, M.A.; Ackerman, J.P.; Verma, S.

1995-01-01

A mineral waste form has been developed for chloride waste salt generated during the pyrochemical treatment of spent nuclear fuel. The waste form consists of salt-occluded zeolite powders bound within a glass matrix. The zeolite contains the salt and immobilizes the fission products. The zeolite powders are hot pressed to form a mechanically stable, durable glass bonded zeolite. Further development of glass bonded zeolite as a waste form requires an understanding of the interaction between the glass and the zeolite. Properties of the glass that enhance binding and durability of the glass bonded zeolite need to be identified. Three types of glass, boroaluminosilicate, soda-lime silicate, and high silica glasses, have a range of properties and are now being investigated. Each glass was hot pressed by itself and with an equal amount of zeolite. MCC-1 leach tests were run on both. Soda-lime silicate and high silica glasses did not give a durable glass bonded zeolite. Boroaluminosilicate glasses rich in alkaline earths did bind the zeolite and gave a durable glass bonded zeolite. Scanning electron micrographs suggest that the boroaluminosilicate glasses wetted the zeolite powders better than the other glasses. Development of the glass bonded zeolite as a waste form for chloride waste salt is continuing

[Study of relationship between powder-size gradation and mechanical properties of Zirconia toughened glass infiltrated nanometer-ceramic composite powder].

Science.gov (United States)

Chai, Feng; Xu, Ling; Liao, Yun-mao; Chao, Yong-lie

2003-07-01

The fabrication of all-ceramic dental restorations is challenged by ceramics' relatively low flexural strength and intrinsic poor resistance to fracture. This paper aimed at investigating the relationships between powder-size gradation and mechanical properties of Zirconia toughened glass infiltrated nanometer-ceramic composite (Al(2)O(3)-nZrO(2)). Al(2)O(3)-nZrO(2) ceramics powder (W) was processed by combination methods of chemical co-precipitation and ball milling with addition of different powder-sized ZrO(2). Field-emission scanning electron microscopy was used to determine the particle size distribution and characterize the particle morphology of powders. The matrix compacts were made by slip-casting technique and sintered to 1,450 degrees C and flexural strength and the fracture toughness of them were measured. 1. The particle distribution of Al(2)O(3)-nZrO(2) ceramics powder ranges from 0.02 - 3.5 micro m and among them the superfine particles almost accounted for 20%. 2. The ceramic matrix samples with addition of nZrO(2) (W) showed much higher flexural strength (115.434 +/- 5.319) MPa and fracture toughness (2.04 +/- 0.10) MPa m(1/2) than those of pure Al(2)O(3) ceramics (62.763 +/- 7.220 MPa; 1.16 +/- 0.02 MPa m(1/2)). The particle size of additive ZrO(2) may impose influences on mechanical properties of Al(2)O(3)-nZrO(2) ceramics matrix. Good homogeneity and reasonable powder-size gradation of ceramic powder can improve the mechanical properties of material.

Some aspects of UO{sub 2} powder production

Energy Technology Data Exchange (ETDEWEB)

Balakrishna, P; Asnani, C K; Prabhakar Rao, L; Kartha, R M; Pillai, P K.M. [Nuclear Fuel Complex, Hyderabad (India)

1994-06-01

UO{sub 2} powder is being produced in a chemical plant from enriched UF{sub 6} and supplied to the pelletizing plant. Small quantities of scrap UO{sub 2} received back from the pelletizing plant are also recycled in the chemical plant to produce UO{sub 2} powder. The powder should be of a consistently high quality so as to finally yield high density sintered pellets with minimum rejection. The final yield of acceptable finished pellets depends on the quality of the powder in the chemical plant as well as the quality of pressing in the pelletizing plant. In this paper, some examples of measures adopted for achieving good quality powder production are presented. (author). 9 refs., 2 figs.

Processing of tungsten scrap into powders by electroerosion disintegration

International Nuclear Information System (INIS)

Fominskii, L.P.; Leuchuk, M.V.; Myuller, A.S.; Tarabrina, V.P.

1985-01-01

Utilization of tungsten and tungsten alloy swarf and other waste and also of rejected and worn parts is a matter of great importance in view of the shortage of this metal. The authors examine the electroerosion (EE) disintegration of tungsten in water as a means of utilizing swarf and other loose waste. Unlike chemical methods, EE disintegration ensures ecological purity since there are no effluent waters or toxic discharges. Swarf and trimmings of rods of diameters up to 20 mm obtained after the lathe-turning of tungsten bars sintered from PVN and PVV tungsten powders were disintegrated in water at room temperature between tungsten electrodes. The phase composition of the powder was studied using FeK /SUB alpha/ radiation, by x-ray diffraction methods in a DRON-2 diffractometer with a graphite monochromator on the secondary beam. When tungsten is heated to boiling during EE disintegration, the impurities present in it can evaporate and burn out. Thus, tungsten powder produced by EE disintegration can be purer than the starting metal

Role of forgings in powder metallurgy industry

International Nuclear Information System (INIS)

Hayes, A.F.; DeRidder, A.J.

1975-01-01

Forging of powder metallurgy materials is discussed. Information and data are included on forging powder metallurgy W, Mo, In 100, Rene 95, Astroloy, Be, and Ti. It is noted that the combination of powder metallurgy and forging work provides the best product from standpoints of reproducibility, freedom from segregation, low scrap rate, and uniform mechanical properties. Experience is being used to develop contour forging from hot isostatic pressed billets or preforms. The quality of this product is under evaluation. Results show steady improvement and it is anticipated that continued effort will soon produce a reliable, less costly product. Forging can continue to be relied upon to correct subtle defects present in powder metallurgy material

Modeling the energy content of combustible ship-scrapping waste at Alang-Sosiya, India, using multiple regression analysis.

Science.gov (United States)

Reddy, M Srinivasa; Basha, Shaik; Joshi, H V; Sravan Kumar, V G; Jha, B; Ghosh, P K

2005-01-01

Alang-Sosiya is the largest ship-scrapping yard in the world, established in 1982. Every year an average of 171 ships having a mean weight of 2.10 x 10(6)(+/-7.82 x 10(5)) of light dead weight tonnage (LDT) being scrapped. Apart from scrapped metals, this yard generates a massive amount of combustible solid waste in the form of waste wood, plastic, insulation material, paper, glass wool, thermocol pieces (polyurethane foam material), sponge, oiled rope, cotton waste, rubber, etc. In this study multiple regression analysis was used to develop predictive models for energy content of combustible ship-scrapping solid wastes. The scope of work comprised qualitative and quantitative estimation of solid waste samples and performing a sequential selection procedure for isolating variables. Three regression models were developed to correlate the energy content (net calorific values (LHV)) with variables derived from material composition, proximate and ultimate analyses. The performance of these models for this particular waste complies well with the equations developed by other researchers (Dulong, Steuer, Scheurer-Kestner and Bento's) for estimating energy content of municipal solid waste.

ORO scrap metal decontamination program

International Nuclear Information System (INIS)

Jugan, M.

1987-01-01

The Oak Ridge Operations Office (ORO) of the US Department of Energy (DOE) has approximately 80,000 tons of contaminated scrap metal at the Oak Ridge Gaseous Diffusion Plant in Oak Ridge, Tennessee; Paducah Gaseous Diffusion Plant in Paducah, Kentucky; Portsmouth Gaseous Diffusion Plant in Piketon, Ohio; and the Feed Materials Production Center in Fernald, Ohio. After unsuccessful in-house attempts to eliminate/recycle the contaminated metal, DOE is allowing private enterprise the opportunity to participate in this program. DOE is making this opportunity available under a two-phase approach, which is being supported by two separate and corresponding Request for Proposals. Phase I, which is nearing completion, is a demonstration phase to establish a group of companies that the DOE will consider qualified to eliminate the scrap at one or more sites. In Phase I, the companies decontaminated 25-50 tons of scrap to demonstrate capabilities to DOE and to gain the knowledge required to plan/bid on elimination of the scrap at one or more sites. Phase II will request proposals for elimination of the total scrap at one or more of the above noted sites. Multiple awards for Phase II are also anticipated. Companies participating in Phase II will be required to take title to the contaminated scrap and decontaminate/process the scrap for beneficial reuse. Radioactive wastes and metal that cannot be successfully decontaminated/processed will be returned to DOE

Application of new synchrotron powder diffraction techniques to anomalous scattering from glasses

International Nuclear Information System (INIS)

Beno, M.A.; Knapp, G.S.; Armand, P.; Price, D.L.; Saboungi, M.

1995-01-01

We have applied two synchrotron powder diffraction techniques to the measurement of high quality anomalous scattering diffraction data for amorphous materials. One of these methods, which uses a curved perfect crystal analyzer to simultaneously diffract multiple powder lines into a position sensitive detector has been shown to possess high resolution, low background, and very high counting rates. This data measurement technique provides excellent energy resolution while minimizing systematic errors resulting from detector nonlinearity. Anomalous scattering data for a Cesium Germanate glass collected using this technique will be presented. The second powder diffraction technique uses a flat analyzer crystal to deflect multiple diffraction lines out of the equatorial plane. Calculations show that this method possesses sufficient energy resolution for anomalous scattering experiments when a perfect crystal analyzer is used and is experimentally much simpler. Future studies will make use of a rapid sample changer allowing the scattering from the sample and a standard material (a material not containing the anomalous scatterer) to be measured alternately at each angle, reducing systematic errors due to beam instability or sample misalignment

7 CFR 29.2277 - Leaf scrap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2277 Section 29.2277 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... scrap. A byproduct of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and consists...

32 CFR 644.522 - Clearance of military scrap.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... destruction, by using command, of all military scrap and scrap metal from lands suitable for cultivation or...

7 CFR 29.3526 - Leaf scrap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3526 Section 29.3526 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3526 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results from handling...

7 CFR 29.3034 - Leaf scrap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.3034 Section 29.3034 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Leaf scrap. A by-product of unstemmed tobacco. Leaf scrap results from handling unstemmed tobacco and...

7 CFR 29.6022 - Leaf scrap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.6022 Section 29.6022 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6022 Leaf scrap. A byproduct of unstemmed tobacco Leaf scrap results...

Direct synthesis of nano-sized glass powders with spherical shape by RF (radio frequency) thermal plasma

International Nuclear Information System (INIS)

Seo, J.H.; Kim, J.S.; Lee, M.Y.; Ju, W.T.; Nam, I.T.

2011-01-01

A new route for obtaining very small, spheroid glass powders is demonstrated using an RF (radio frequency) thermal plasma system. During the process, four kinds of chemicals, here SiO 2 , B 2 O 3 , BaCO 3 , and K 2 CO 3 , were mixed at pre-set weight ratios, spray-dried, calcined at 250 deg. C for 3 h, and crushed into fragments. Then, they were successfully reformed into nano-sized amorphous powders (< 200 nm) with spherical shape by injecting them along the centerline of an RF thermal plasma reactor at ∼ 24 kW. The as-synthesized powders show negligible (< 1%) composition changes when compared with the injected precursors of raw material compounds.

Superconducting glass-ceramics in BiSrCaCu2Al0.5Ox---Comparison between rod and powder compacted specimens

International Nuclear Information System (INIS)

Hirata, K.; Abe, Y.

1991-01-01

Superconducting properties are studied for glass-ceramics which were prepared by reheating glass rods and the glass powder compacts in the BiSrCaCu 2 Al 0.5 O x system, respectively. The glass-ceramic rod specimens obtained by reheating rod glass at 800--830 degree C for 50 h have a T c (R=0) of 85 K, while the disk specimens obtained by reheating the powered glass compacts in the same way do not exhibit superconductivity above 77 K. This difference in superconductivity between the specimens is discussed in terms of crystallization process and the amount of oxygen absorption of the specimens during heating

Osteoconductive properties of two different bioactive glass forms (powder and fiber) combined with collagen

Science.gov (United States)

Magri, Angela Maria Paiva; Fernandes, Kelly Rossetti; Ueno, Fabio Roberto; Kido, Hueliton Wilian; da Silva, Antonio Carlos; Braga, Francisco José Correa; Granito, Renata Neves; Gabbai-Armelin, Paulo Roberto; Rennó, Ana Claudia Muniz

2017-11-01

Bioactive Glasses (BG) is a group of synthetic silica-based materials with the unique ability to bond to living bone and can be used in bone repair. Although the osteogenic potential of BG, this material may have not present sufficient osteoconductive and osteoinductive properties to allow bone regeneration, especially in compromised situations. In order to overcome this limitation, it was proposed the combination the BG in two forms (powder and fiber) combined with collagen type I (COL-1). The aim of this study was to evaluate the BG/COL-based materials in terms of morphological characteristics, physicochemical features and mineralization. Additionally, the second objective was to investigate and compare the osteoconductive properties of two different bioactive glass forms (powder and fiber) enriched or not with collagen using a tibial bone defect model in rats. For this, four different formulations (BG powder - BGp, BG powder enriched with collagen - BGp/Col, BG fibers - BGf and BGp fibers enriched with collagen - BGf/Col) were developed. The physicochemical and morphological modifications were analyzed by SEM, FTIR, calcium assay and pH measurement. For in vivo evaluations, histopathology, morphometrical and immunohistochemistry were performed in a tibial defect in rats. The FTIR analysis indicated that BGp and BGf maintained the characteristic peaks for this class of material. Furthermore, the calcium assay showed an increased Ca uptake in the BG fibers. The pH measurements revealed that BGp (with or without collagen) presented higher pH values compared to BGf. In addition, the histological analysis demonstrated no inflammation for all groups at the site of the injury, besides a faster material degradation and higher bone ingrowth for groups with collagen. The immunohistochemistry analysis demonstrated Runx-2 and Rank-L expression for all the groups. Those findings support that BGp with collagen can be a promising alternative for treating fracture of difficult

Leachability of heavy metals from scrap dirt sampled at two scrap iron and metal recycling facilities

DEFF Research Database (Denmark)

Jensen, Dorthe Lærke; Holm, Peter Engelund; Christensen, Thomas Højlund

2000-01-01

Column and batch leaching experiments were performed to quantify leaching of heavy metals (Pb, Cu, Cd and Zn) from scrap dirt representing different activities at two iron scrap and metal recycling facilities. The scrap dirt is often found directly upon the bare unprotected soil at recycling...... battery salvage locations was different, showing lower pH and signi®cant leaching of lead (up to 8000 mg Pb l±1), cadmium (up to 40 mg Cd l±1), and zinc (up to 2000 mg Zn l±1). The column and batch leaching experiments gave comparable results at the order of magnitude level, and both approaches are......, at that level, useful for evaluation of leaching potentials from scrap dirt. The experiments showed that scrap dirt at recycling facilities constitutes only a modest leaching problem, but a long-term soil pollution problem from a land-use perspective. Leaching experiments with compost solution indicated...

7 CFR 29.1169 - Scrap (S Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.1169 Section 29.1169 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Grades § 29.1169 Scrap (S Group). A byproduct of stemmed and unstemmed tobacco. Scrap...

7 CFR 29.2441 - Scrap (S Group).

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Scrap (S Group). 29.2441 Section 29.2441 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Grades § 29.2441 Scrap (S Group). A byproduct of unstemmed and stemmed tobacco. Scrap...

Preliminary study in development of glass-ceramic based on SiO2-LiO2 system, starting of different SiO2 starting powders

International Nuclear Information System (INIS)

Daguano, J.K.M.F.; Santos, F.A.; Santos, C.; Marton, L.F.M.; Conte, R.A.; Rodrigues Junior, D.; Melo, F.C.L.

2009-01-01

In this work, lithium disilicate glass-ceramics were developed starting of the rice ash- SiO 2 and Li 2 CO 3 powders. The results were compared with glass ceramics based on the lithium disilicate obtained by commercial SiO 2 powders. Glass were melted at 1580 deg C, and annealed at 850 deg C. X-Ray diffraction and scanning electron microscopy were used for characterization of the materials, and hardness and fracture toughness were evaluated using Vickers indentation method. Glasses with amorphous structure were obtained in both materials. After annealing, 'rice-ash' samples presented Li 2 SiO 3 and residual SiO 2 as crystalline phases. On the other side, commercial SiO 2 - Samples presented only Li 2 Si 2 O 5 as crystalline phases and the better results of hardness and fracture toughness. (author)

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

Anisotropic powder from sintered NdFeB magnets by the HDDR processing route

Energy Technology Data Exchange (ETDEWEB)

Sheridan, R.S.; Sillitoe, R.; Zakotnik, M.; Harris, I.R. [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Williams, A.J., E-mail: a.j.williams@bham.ac.uk [School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

2012-01-15

Sintered NdFeB-based scrap magnets were recovered and processed using the HD and HDDR routes. The effects of varying the HDDR processing temperature were investigated (over the range 835-930 deg. C). The disproportion was carried out with a pressure ramp to a maximum of 1000 mbar hydrogen pressure with a 1 h hold time at each step and the optimum recombination conditions were set at 100 mbar with a 20 min hold time. Anisotropic NdFeB powder was produced in all cases with the best magnetic properties achieved at a processing temperature of 880 deg. C, producing powder with a remanence of 1.10({+-}0.02) T and an intrinsic coercivity of 800 ({+-}16) kA m{sup -1} and giving a (BH){sub max} of 129({+-}2.5) kJ m{sup -3}. - Highlights: > Production of anisotropic permanent magnet powder from scrap NdFeB magnets by HDDR. > Reaction pressure increases with increasing processing temperature. > Best magnetic properties achieved by processing at 880 deg. C.

Anisotropic powder from sintered NdFeB magnets by the HDDR processing route

International Nuclear Information System (INIS)

Sheridan, R.S.; Sillitoe, R.; Zakotnik, M.; Harris, I.R.; Williams, A.J.

2012-01-01

Sintered NdFeB-based scrap magnets were recovered and processed using the HD and HDDR routes. The effects of varying the HDDR processing temperature were investigated (over the range 835-930 deg. C). The disproportion was carried out with a pressure ramp to a maximum of 1000 mbar hydrogen pressure with a 1 h hold time at each step and the optimum recombination conditions were set at 100 mbar with a 20 min hold time. Anisotropic NdFeB powder was produced in all cases with the best magnetic properties achieved at a processing temperature of 880 deg. C, producing powder with a remanence of 1.10(±0.02) T and an intrinsic coercivity of 800 (±16) kA m -1 and giving a (BH) max of 129(±2.5) kJ m -3 . - Highlights: → Production of anisotropic permanent magnet powder from scrap NdFeB magnets by HDDR. → Reaction pressure increases with increasing processing temperature. → Best magnetic properties achieved by processing at 880 deg. C.

Fernald scrap metal recycling and beneficial reuse

International Nuclear Information System (INIS)

Motl, G.P.; Burns, D.D.

1993-10-01

The Fernald site, formerly the Feed Materials Production Facility, produced uranium metal products to meet defense production requirements for the Department of Energy from 1953 to 1989. In this report is is described how the Fernald scrap metal project has demonstrated that contractor capabilities can be used successfully to recycle large quantities of Department of Energy scrap metal. The project has proven that the open-quotes beneficial reuseclose quotes concept makes excellent economic sense when a market for recycled products can be identified. Topics covered in this report include the scrap metal pile history, the procurement strategy, scrap metal processing, and a discussion of lessons learned

Direct conversion of plutonium metal, scrap, residue, and transuranic waste to glass

International Nuclear Information System (INIS)

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.; Malling, J.F.; Rudolph, J.

1995-01-01

A method for the direct conversion of metals, ceramics, organics, and amorphous solids to borosilicate glass has been invented. The process is called the Glass Material Oxidation and Dissolution System (GMODS). Traditional glass-making processes can convert only oxide materials to glass. However, many wastes contain complex mixtures of metals, ceramics, organics, and amorphous solids. Conversion of such mixtures to oxides followed by their conversion to glass is often impractical. GMODS may create a practical method to convert such mixtures to glass. Plutonium-containing materials (PCMS) exist in many forms, including metals, ceramics, organics, amorphous solids, and mixtures thereof. These PCMs vary from plutonium metal to filters made of metal, organic binders, and glass fibers. For storage and/or disposal of PCMS, it is desirable to convert PCMs to borosilicate glass. Borosilicate glass is the preferred repository waste form for high-level waste (HLW) because of its properties. PCMs converted to a transuranic borosilicate homogeneous glass would easily pass all waste acceptance and storage criteria. Conversion of PCMs to a glass would also simplify safeguards by conversion of heterogeneous PCMs to homogeneous glass. Thermodynamic calculations and proof-of-principle experiments on the GMODS process with cerium (plutonium surrogate), uranium, stainless steel, aluminum, Zircaloy-2, and carbon were successfully conducted. Initial analysis has identified potential flowsheets and equipment. Major unknowns remain, but the preliminary data suggests that GMODS may be a major new treatment option for PCMs

The analysis of lightweight brick strength pressure with mixture of glass powder and silica fume

Science.gov (United States)

Nursyamsi; Liang, William

2018-03-01

Little by little the engineers research how the development of concrete that can utilize waste. In the utilization of the waste, it can be functioned as mixing material which the chemical or the physical traits of the used goods contain similarity to the mixture of concrete in general, one of them is glass powder as the substitute of cement. The glass powder that utilizes is the one that is sifted through sieve No. 200 as much as 10% of the weight of the cement. The testing specimen of the concrete brick is make of the mixture with the ratio of 1:7, then is added with the foaming agent (1:30) and silica fume (10% of the weight of the cement). Furthermore, visual examination, absorption, net weight and testing specimen compressive strength. The data analysis uses the reference of SNI 03 – 0349 – 1989 regarding Concrete Brick for the Match for the Wall. Foaming Agent is make by using modified hand drill and brace. The testing specimen uses the brick mold with the size of 40 cm x 20cm x 10 cm. Based on this research, it shows that the quality that results from brick is still qualified based on SNI 03 – 0349 – 1989.

The new MAW scrap processing facility

International Nuclear Information System (INIS)

Kueppers, L.

1994-01-01

The shielded bunker for heat-generating waste attached to the MAW scrap processing cell will be modified and extended to comprise several MAW scrap processing cells of enhanced throughput capacity, and a new building to serve as an airlock and port for acceptance of large shipping casks (shipping cask airlock, TBS). The new facility is to process scrap from decommissioned nuclear installations, and in addition radwaste accrued at operating plants of utilities. This will allow efficient and steady use of the new MAW scrap processing facility. The planning activities for modification and extension are based on close coordination between KfK and the GNS mbH, in order to put structural dimensioning and capacity planning on a realistic basis in line with expected amounts of radwaste from operating nuclear installations of utilities. The paper indicates the currently available waste amount assessments covering solid radwaste (MAW) from the decommissioning of the WAK, MZFR, and KNK II, and existing waste amounts consisting of core internals of German nuclear power plant. The figures show that the MAW scrap processing facility will have to process an overall bulk of about 1100 Mg of solid waste over the next ten years to come. (orig./HP) [de

7 CFR 29.2529 - Leaf scrap.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf scrap. 29.2529 Section 29.2529 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... tobacco. Leaf scrap results from handling unstemmed tobacco and consists of loose and tangled whole or...

Radiation survey of aircraft and heavy machinery scrap

International Nuclear Information System (INIS)

Idriss, Hajo; Salih, Isam; Gumaa, Elsadig; Yassin, Abbas; Yousif, E.H.; Abdel Hamid, Saad Eldeen M.; Sam, A.K.

2012-01-01

This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of 90 Sr and one of 226 Ra in aircraft scrap. Of course, 90 Sr sources are used in military aircraft as temperature sensors while 226 Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1 m from the source fall within the range of 25.1–40.2 μSv/h with an average value of 33.52±4.06 μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing. - Highlights: ► Sealed radioactive sources ( 90 Sr and 226 Ra) were detected in aircraft scrap. ► No source was detected in heavy machine scrap. ► Radiation dose measured at 0.1 m from the source can be used to estimate exposure to public. ► Monitoring of scrap was found to be useful for protection (from orphan sources).

Feasibility of re-melting NORM-contaminated scrap metal

Energy Technology Data Exchange (ETDEWEB)

Winters, S. J.; Smith, K. P.

1999-10-26

Naturally occurring radioactive materials (NORM) sometimes accumulate inside pieces of equipment associated with oil and gas production and processing activities. Typically, the NORM accumulates when radium that is present in solution in produced water precipitates out in scale and sludge deposits. Scrap equipment containing residual quantities of these NORM-bearing scales and sludges can present a waste management problem if the radium concentrations exceed regulatory limits or activate the alarms on radiation screening devices installed at most scrap metal recycling facilities. Although NORM-contaminated scrap metal currently is not disposed of by re-melting, this form of recycling could present a viable disposition option for this waste stream. Studies indicate that re-melting NORM-contaminated scrap metal is a viable recycling option from a risk-based perspective. However, a myriad of economic, regulatory, and policy issues have caused the recyclers to turn away virtually all radioactive scrap metal. Until these issues can be resolved, re-melting of the petroleum industry's NORM-impacted scrap metal is unlikely to be a widespread practice. This paper summarizes the issues associated with re-melting radioactive scrap so that the petroleum industry and its regulators will understand the obstacles. This paper was prepared as part of a report being prepared by the Interstate Oil and Gas Compact Commission's NORM Subcommittee.

[Influence of La2O3 and Li2O on glass powder for infiltrating ZTA all-ceramic dental material formed by gel-casting].

Science.gov (United States)

Jin, Qiong; Wang, Xiao-fei; Yang, Zheng-yu; Tong, Yi-ping; Zhu, Li; Ma, Jian-feng

2012-10-01

The influence of La2O3 and Li2O on glass powder was studied in this paper, which is to infiltrate ZTA all-ceramic dental material formed by gel-casting. The performance of different component was analyzed to optimize glass formula. Six groups of glass powder were designed and prepared by conventional melt-quenching method. ZTA ceramic blocks were covered with glass paste, which were formed by gel-casting and sintered in 1200 degrees centigrade, then infiltrated in 1150 degrees centigrade for twice to make glass/ZTA ceramic composites. By detecting differential thermal analysis and melting range of infiltration glass power, as well as flexural strength, linear shrinkage, SEM and EDS of glass/ZTA ceramic composites, the optimized glass group was determined out. Statistical analysis was performed using SPSS 13.0 software package by means of paired t test or one way ANOVA. The bending strength of group Li1 was (291.2±27.9) MPa, significantly higher than group Li2 and group La2(Pglass of group Li1 can lubricate ZTA ceramics well, their structure was compact and had a few small pores. Intergranular fracture existed on cross surface as well as transgranular fracture. The results showed that Li1(30%La2O3-15%Al2O3-15%SiO2-15%B2O3-5%Li2O) glass infiltrated ZTA ceramic composite had the best capability. Glass/ZTA composite material can be prepared by gel-casting and infiltrating way, and this process is simple and economically suitable for general dental laboratory.

Thermo-Mechanical Properties of Unsaturated Polyester Reinforced with SiliconCarbide Powder And with Chopped Glass Fiber

Directory of Open Access Journals (Sweden)

Bushra Hosnie Musa

2018-02-01

Full Text Available The work studied the effectoffine silicon carbide (SiC powder with (0,3,5,7wt % on the thermal conductivity and mechanical properties of unsaturated polyester composite in the presence of a fixed amount of chopped glass fiber. The hand lay-up technique was employed to preparethe required samples. Results showed that tensile, impact strength and thermal conductivity increased with increasing the weight fraction of reinforced materials.

Preparation and characterization of physically modified glass beads used as model carriers in dry powder inhalers.

Science.gov (United States)

Zellnitz, Sarah; Redlinger-Pohn, Jakob Dominik; Kappl, Michael; Schroettner, Hartmuth; Urbanetz, Nora Anne

2013-04-15

The aim of this work is the physical modification and characterization of the surface topography of glass beads used as model carriers in dry powder inhalers (DPIs). By surface modification the contact area between drug and carrier and thereby interparticle forces may be modified. Thus the performance of DPIs that relies on interparticle interactions may be improved. Glass beads were chosen as model carriers because various prospects of physical surface modification may be applied without affecting other factors also impacting interparticle interactions like particle size and shape. To generate rough surfaces glass beads were processed mechanically by friction and impaction in a ball mill with different grinding materials that were smaller and harder with respect to the glass beads. By varying the grinding time (4 h, 8 h) and by using different grinding media (tungsten carbide, quartz) surfaces with different shades of roughness were generated. Depending on the hardness of the grinding material and the grinding time the surface roughness was more or less pronounced. Surface roughness parameters and specific surface area were determined via several complementary techniques in order to get an enhanced understanding of the impact of the modifying procedure on the surface properties of the glass beads. Copyright © 2013 Elsevier B.V. All rights reserved.

Technical Review of the Characteristics of Spent Nuclear Fuel Scrap

International Nuclear Information System (INIS)

Kuhn, William L.; Abrefah, John; Pitner, Allen L.; Damschen, Dennis W.

2000-01-01

Spent Nuclear Fuel scrap generated while washing the SNF in Hanford's K-Basins to prepare it for cold vacuum drying differed significantly from that envisioned during project design. Therefore, a technical review panel evaluated the new information about the physical characteristics of scrap generated during processing by characterizing it based on measured weights and digital photographic images. They examined images of the scrap and from them estimated the volume and hence the masses of inert material and of large fragments of spent fuel. The panel estimated the area of these particles directly from images and by fitting a lognormal distribution to the relative number particles in four size ranges and then obtaining the area-to-volume ratio from the distribution. The estimated area is 0.3 m2 for the mass of scrap that could be loaded into a container for drying, which compares to a value of 4.5 m2 assumed for safe operation of the baseline process. The small quantity of scrap genera ted is encouraging. However, the size and mass of the scrap depend both on processes degrading the fuel while in the basin and on processes catching the scrap during washing, the latter including essentially unintentional filtration as debris accumulates. Therefore, the panel concluded that the estimated surface area meets the criterion for loading scrap into an MCO for drying, but because it did not attempt to evaluate the criterion itself, it is not in a position to actually recommend loading the scrap. Further, this is not a sufficiently strong technical position from which to extrapolate the results from the examined scrap to all future scrap generated by the existing process

Management options for recycling radioactive scrap metals

Energy Technology Data Exchange (ETDEWEB)

Dehmel, J.C.; MacKinney, J.; Bartlett, J.

1997-02-01

The feasibility and advantages of recycling radioactive scrap metals (RSM) have yet to be assessed, given the unique technical, regulatory, safety, and cost-benefit issues that have already been raised by a concerned recycling industry. As is known, this industry has been repeatedly involved with the accidental recycling of radioactive sources and, in some cases, with costly consequences. If recycling were deemed to be a viable option, it might have to be implemented with regulatory monitoring and controls. Its implementation may have to consider various and complex issues and address the requirements and concerns of distinctly different industries. There are three basic options for the recycling of such scraps. They are: (1) recycling through the existing network of metal-scrap dealers and brokers, (2) recycling directly and only with specific steelmills, or (3) recycling through regional processing centers. Under the first option, scrap dealers and brokers would receive material from RSM generators and determine at which steelmills such scraps would be recycled. For the second option, RSM generators would deal directly with selected steelmills under specific agreements. For the third option, generators would ship scraps only to regional centers for processing and shipment to participating steelmills. This paper addresses the potential advantages of each option, identifies the types of arrangements that would need to be secured among all parties, and attempts to assess the receptivity of the recycling industry to each option.

Fabrication of microfluidic mixers with varying topography in glass using the powder-blasting process

International Nuclear Information System (INIS)

Sayah, Abdeljalil; Thivolle, Pierre-Antoine; Parashar, Virendra K; Gijs, Martin A M

2009-01-01

The powder-blasting method is used to fabricate structures with a three-dimensional topography in glass using elastomeric masks. The relation between the mask opening width and the erosion depth is exploited to fabricate microstructures with varying depth in a single micropatterning step. As an application, planar three-dimensional micro-mixers were fabricated, which consist of a repeating convergent microfluidic nozzle structure. Three different designs of the micro-mixers were considered. The mixing of co-flowing laminar streams results from the generation of multiple vortices at the exit of the different convergent nozzles

Evaluation of workability and strength of green concrete using waste steel scrap

Science.gov (United States)

Neeraja, D.; Arshad, Shaik Mohammed; Nawaz Nadaf, Alisha K.; Reddy, Mani Kumar

2017-11-01

This project works on the study of workability and mechanical properties of concrete using waste steel scrap from the lathe industry. Lathe industries produce waste steel scrap from the lathe machines. In this study, an attempt is made to use this waste in concrete, as accumulation of waste steel scrap cause disposal problem. Tests like compressive test, split tensile test, NDT test (UPV test) were conducted to determine the impact of steel scrap in concrete. The percentages of steel scrap considered in the study were 0%, 0.5%, 1%, 1.5%, and 2% respectively by volume of concrete, 7 day, 28 days test were conducted to find out strength of steel scrap concrete. It is observed that split tensile strength of steel scrap concrete is increased slightly. Split tensile strength of Steel scrap concrete is found to be maximum with volume fraction of 2.0% steel scrap. The steel scrap gives good result in split tensile strength of concrete. From the study concluded that steel scrap can be used in concrete to reduce brittleness of concrete to some extent.

Self-powdering and nonlinear optical domain structures in ferroelastic β'-Gd2(MoO4)3 crystals formed in glass

International Nuclear Information System (INIS)

Tsukada, Y.; Honma, T.; Komatsu, T.

2009-01-01

Ferroelastic β'-Gd 2 (MoO 4 ) 3 , (GMO), crystals are formed through the crystallization of 21.25Gd 2 O 3 -63.75MoO 3 -15B 2 O 3 glass (mol%), and two scientific curious phenomena are observed. (1) GMO crystals formed in the crystallization break into small pieces with a triangular prism or pyramid shape having a length of 50-500 μm spontaneously during the crystallizations in the inside of an electric furnace, not during the cooling in air after the crystallization. This phenomenon is called 'self-powdering phenomenon during crystallization' in this paper. (2) Each self-powdered GMO crystal grain shows a periodic domain structure with different refractive indices, and a spatially periodic second harmonic generation (SHG) depending on the domain structure is observed. It is proposed from polarized micro-Raman scattering spectra and the azimuthal dependence of second harmonic intensities that GMO crystals are oriented in each crystal grain and the orientation of (MoO 4 ) 2- tetrahedra in GMO crystals changes periodically due to spontaneous strains in ferroelastic GMO crystals. - Graphical abstract: This figure shows the polarized optical photograph at room temperature for a particle (piece) obtained by a heat treatment of the glass at 590 deg. C for 2 h in an electric furnace in air. This particle was obtained through the self-powdering behavior in the crystallization of glass. The periodic domain structure is observed. Ferroelastic β'-Gd 2 (MoO 4 ) 3 crystals are formed in the particle, and second harmonic generations are detected, depending on the domain structure.

Detection of radioactivity in scrap in Germany

International Nuclear Information System (INIS)

Kugeler, E.; Thierfeldt, S.; Sefzig, R.; Weimer, G.

1999-01-01

Although Germany's scrap export exceeds the import, the imports of scrap amount to more than one million Mg per year. Radioactivity has been found mainly in imported scrap in Germany. This radioactivity can consist of surface contamination in scrap e.g. from the oil and gas industry, nuclear and other technical applications or of radiation sources, e.g. from medical or technical irradiation devices where the source has not been removed prior to scrapping. Fortunately really large sources have been involved in only very few occasions. More serious incidents have, however, been reported from other countries. Today, measurement facilities have been installed at the entrances to virtually all German foundries and larger scrap yards. These measurement facilities allow the swift measurement of whole lorry or freight car loads. The lower limit of detection is for some devices as low as ca. 5 nSv/h (dose rate increase above background at the detector) which is achieved by very advanced hardware and software. Additionally, simplified dose rate measurements are performed by German customs officials at the eastern borders for scrap loads to be imported into Germany. When activity is detected in a load, several options exist, like e.g.: (i) sending the scrap back to the sender; (ii) allowing the whole load to be melted down; (iii) careful unloading and separating the load with the aim of localizing and removing the contamination. This paper analyses these various options after detection, discusses the role of the competent authorities and evaluates the possible radiological consequences. Realistic dose calculations show that it is possible that a person may receive doses of several mSv or even 10 mSv if precautionary measures are neglected or if a larger source is not detected at all. This paper further addresses which types and amounts of radioactivity may be detected and which conclusions can be drawn from the dose rate at the detector. The continuous increase in the number

Mercury-impacted scrap metal: Source and nature of the mercury.

Science.gov (United States)

Finster, Molly E; Raymond, Michelle R; Scofield, Marcienne A; Smith, Karen P

2015-09-15

The reuse and recycling of industrial solid wastes such as scrap metal is supported and encouraged both internationally and domestically, especially when such wastes can be used as substitutes for raw material. However, scrap metal processing facilities, such as mini-mills, have been identified as a source of mercury (Hg) emissions in the United States. This research aims to better define some of the key issues related to the source and nature of mercury in the scrap metal waste stream. Overall, it is difficult to pinpoint the key mercury sources feeding into scrap metal recycling facilities, quantify their associated mercury concentrations, or determine which chemical forms are most significant. Potential sources of mercury in scrap metal include mercury switches from discarded vehicles, electronic-based scrap from household appliances and related industrial systems, and Hg-impacted scrap metal from the oil and gas industry. The form of mercury associated with scrap metal varies and depends on the source type. The specific amount of mercury that can be adsorbed and retained by steel appears to be a function of both metallurgical and environmental factors. In general, the longer the steel is in contact with a fluid or condensate that contains measurable concentrations of elemental mercury, the greater the potential for mercury accumulation in that steel. Most mercury compounds are thermally unstable at elevated temperatures (i.e., above 350 °C). As such, the mercury associated with impacted scrap is expected to be volatilized out of the metal when it is heated during processing (e.g., shredding or torch cutting) or melted in a furnace. This release of fugitive gas (Hg vapor) and particulates, as well as Hg-impacted bag-house dust and control filters, could potentially pose an occupational exposure risk to workers at a scrap metal processing facility. Thus, identifying and characterizing the key sources of Hg-impacted scrap, and understanding the nature and extent

Production of NdFeB powders by HDDR from sintered magnets

International Nuclear Information System (INIS)

Janasi, S.R.; Rodrigues, D.; Landgraf, F.J.G.; Campos, M.F. de

2010-01-01

The production of NdFeB powders by the HDDR process from metallic alloys has been widely investigated. Different HD and DR conditions have been used to induce anisotropy and to improve the intrinsic coercivity of the obtained powders. The purpose of this study is to apply the HDDR process in the reprocessing of NdFeB sintered magnet scraps. There were investigated different processing conditions as temperature and time of desorption and recombination (DR). The results of X ray diffraction show the formation of the magnetic phase Nd 2 Fe 14 B in all the investigated conditions. Magnetic measurements by vibrating sample magnetometer indicate that powders with intrinsic coercivity up to 790 kA/m were obtained. (author)

Contaminated nickel scrap processing

International Nuclear Information System (INIS)

Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

1994-12-01

The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include 234 Th, 234 Pa, 137 Cs, 239 Pu (trace), 60 Co, U, 99 Tc, and 237 Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs

Cost-assessment Analysis of Local Vehicle Scrapping Facility

Science.gov (United States)

Grabowski, Lukasz; Gliniak, Maciej; Polek, Daria; Gruca, Maria

2017-12-01

The purpose of the paper was to analyse the costs of recycling vehicles at local vehicle scrapping facility. The article contains regulations concerning vehicle decommissioning, describes the types of recovery, vehicles recycling networks, analyses the structure of a disassembly station, as well as the financial and institutional system in charge of dealing with the recycling of vehicles in Poland. The authors present the number of scrapped vehicles at local recycling company and the level of achieved recovery and recycling. The research presented in the article shows financial situation of the vehicle scrapping industry. In addition, it has been observed that the number of subsidies are directly proportional to the number of scrapped vehicles, and achieved levels of recycling and recovery depends on the percentage of incomplete vehicles.

Thermal conductivity of glass copper-composite

International Nuclear Information System (INIS)

Kinoshita, Makoto; Terai, Ryohei; Haidai, Haruki

1980-01-01

Glass-metal composites are to be one of the answers for promoting thermal conduction in the glassy solids containing high-level radioactive wastes. In order to investigate the effect of metal addition on thermal conductivity of glasses, glass-copper composites were selected, and the conductivities of the composites were measured and discussed in regards to copper content and microstructure. Fully densified composites were successfully prepared by pressure sintering of the powder mixtures of glass and copper at temperatures above the yield points of the constituent glasses if the copper content was not so much. The conductivity was measured by means of a comparative method, in which the thermal gradient of the specimen was compared with that of quartz glass as standard under thermally steady state. Measurements were carried out at around 50 0 C. The thermal conductivity increased with increasing content of copper depending on the kind of copper powder used. The conductivities of the composites of the same copper content differed considerably each another. Fine copper powder was effective on increasing conductivity, and the conductivity became about threefold of that of glass by mixing the fine copper powder about 10 vol%. For the composites containing the fine copper powder less than 5 vol%, the conductivity obeyed so-called logarithmic rule, one of the mixture rules of conductivity, whereas for composites containing more than 5 vol%, the conductivity remarkably increased apart from the rule. This fact suggests that copper becomes continuous in the composite when the copper content increased beyond 5 vol%. For the composites containing coarse copper powder, the conductivity was increased not significantly, and obeyed an equation derived from the model in which conductive material dispersed in less conductive one. (author)

Fabrication of highly insulating foam glass made from CRT panel glass

DEFF Research Database (Denmark)

König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

2015-01-01

We prepared low-density foam glasses from cathode-ray-tube panel glass using carbon and MnO2 as the foaming agents. We investigated the influence of the carbon and MnO2 concentrations, the glass-powder preparation and the foaming conditions on the density and homogeneity of the pore structure...... and the dependence of the thermal conductivity on the foam density. The results show that the moderate foaming effect of the carbon is greatly improved by the addition of MnO2. A density as low as 131 kg m-3 can be achieved with fine glass powder. The foam density has a slight dependence on the carbon and MnO2...... concentrations, but it is mainly affected by the foaming temperature and the time. The thermal conductivity of the foam-glass samples is lower than that of commercial foam glasses with the same density. The lowest value was determined to be 42 mW m-1 K-1 for a foam glass with a density of 131 kg m-3. A further...

49 CFR 173.218 - Fish meal or fish scrap.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized for...

Application of waste glass in translucent and photocatalytic concrete

NARCIS (Netherlands)

Lieshout, van B.; Spiesz, P.R.; Brouwers, H.J.H.

2012-01-01

Container glass aggregates and glass powder are waste products of the glass recycling industry. In this research, these products are incorporated in self-compacting concrete (SCC) mixtures, replacing conventional aggregates and fine powders. The SCC mixtures were designed using a particle packing

Glass material oxidation and dissolution system: Converting miscellaneous fissile materials to glass

International Nuclear Information System (INIS)

Forsberg, C.W.; Ferrada, J.J.

1996-01-01

The cold war and the development of nuclear energy have resulted in significant inventories of miscellaneous fissile materials (MFMs). MFMs include (1) plutonium scrap and residue, (2) miscellaneous spent nuclear fuel (SNF), (3) certain hot cell wastes, and (4) many one-of-a-kind materials. Major concerns associated with the long-term management of these materials include: safeguards and nonproliferation issues; health, environment, and safety concerns. waste management requirements; and high storage costs. These issues can be addressed by converting the MFMs to glass for secure, long-term storage or repository disposal; however, conventional glass-making processes require oxide-like feed materials. Converting MFMs to oxide-like materials with subsequent vitrification is a complex and expensive process. A new vitrification process has been invented, the Glass Material Oxidation and Dissolution System (GMODS), which directly converts metals, ceramics, and amorphous solids to glass; oxidizes organics with the residue converted to glass; and converts chlorides to borosilicate glass and a secondary sodium chloride (NaCl) stream. Laboratory work has demonstrated the conversion of cerium (a plutonium surrogate), uranium, Zircaloy, stainless steel, multiple oxides, and other materials to glass. However, significant work is required to develop GMODS further for applications at an industrial scale. If implemented, GMODS will provide a new approach to manage these materials

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

Glass dissolution rate measurement and calculation revisited

Energy Technology Data Exchange (ETDEWEB)

Fournier, Maxime, E-mail: maxime.fournier@cea.fr [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France); Ull, Aurélien; Nicoleau, Elodie [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France); Inagaki, Yaohiro [Department of Applied Quantum Physics & Nuclear Engineering, Kyushu University, Fukuoka, 819-0395 (Japan); Odorico, Michaël [ICSM-UMR5257 CEA/CNRS/UM2/ENSCM, Site de Marcoule, BP17171, F-30207, Bagnols sur Cèze (France); Frugier, Pierre; Gin, Stéphane [CEA, DEN, DTCD, SECM, F-30207, Bagnols sur Cèze (France)

2016-08-01

Aqueous dissolution rate measurements of nuclear glasses are a key step in the long-term behavior study of such waste forms. These rates are routinely normalized to the glass surface area in contact with solution, and experiments are very often carried out using crushed materials. Various methods have been implemented to determine the surface area of such glass powders, leading to differing values, with the notion of the reactive surface area of crushed glass remaining vague. In this study, around forty initial dissolution rate measurements were conducted following static and flow rate (SPFT, MCFT) measurement protocols at 90 °C, pH 10. The international reference glass (ISG), in the forms of powders with different particle sizes and polished monoliths, and soda-lime glass beads were examined. Although crushed glass grains clearly cannot be assimilated with spheres, it is when using the samples geometric surface (S{sub geo}) that the rates measured on powders are closest to those found for monoliths. Overestimation of the reactive surface when using the BET model (S{sub BET}) may be due to small physical features at the atomic scale—contributing to BET surface area but not to AFM surface area. Such features are very small compared with the thickness of water ingress in glass (a few hundred nanometers) and should not be considered in rate calculations. With a S{sub BET}/S{sub geo} ratio of 2.5 ± 0.2 for ISG powders, it is shown here that rates measured on powders and normalized to S{sub geo} should be divided by 1.3 and rates normalized to S{sub BET} should be multiplied by 1.9 in order to be compared with rates measured on a monolith. The use of glass beads indicates that the geometric surface gives a good estimation of glass reactive surface if sample geometry can be precisely described. Although data clearly shows the repeatability of measurements, results must be given with a high uncertainty of approximately ±25%. - Highlights: • Initial dissolution

The steel scrap age.

Science.gov (United States)

Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

2013-04-02

Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

Contaminated nickel scrap processing

Energy Technology Data Exchange (ETDEWEB)

Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

1994-12-01

The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

Properties of concrete containing scrap-tire rubber--an overview.

Science.gov (United States)

Siddique, Rafat; Naik, Tarun R

2004-01-01

Solid waste management is one of the major environmental concerns in the United States. Over 5 billion tons of non-hazardous solid waste materials are generated in USA each year. Of these, more than 270 million scrap-tires (approximately 3.6 million tons) are generated each year. In addition to this, about 300 million scrap-tires have been stockpiled. Several studies have been carried out to reuse scrap-tires in a variety of rubber and plastic products, incineration for production of electricity, or as fuel for cement kilns, as well as in asphalt concrete. Studies show that workable rubberized concrete mixtures can be made with scrap-tire rubber. This paper presents an overview of some of the research published regarding the use of scrap-tires in portland cement concrete. The benefits of using magnesium oxychloride cement as a binder for rubberized concrete mixtures are also presented. The paper details the likely uses of rubberized concrete.

Sealed glass coating of high temperature ceramic superconductors

Science.gov (United States)

Wu, Weite; Chu, Cha Y.; Goretta, Kenneth C.; Routbort, Jules L.

1995-01-01

A method and article of manufacture of a lead oxide based glass coating on a high temperature superconductor. The method includes preparing a dispersion of glass powders in a solution, applying the dispersion to the superconductor, drying the dispersion before applying another coating and heating the glass powder dispersion at temperatures below oxygen diffusion onset and above the glass melting point to form a continuous glass coating on the superconductor to establish compressive stresses which enhance the fracture strength of the superconductor.

Developments in radioactive scrap monitoring

International Nuclear Information System (INIS)

Bellian, J.G.

1997-01-01

Over the past ten years there have been major developments in radiation monitoring systems used for detecting shielded radioactive sources in scrap metal. The extent of the problem and industry's awareness of the problem have both grown significantly during that time. The multimillion dollar expenses associated with decontamination after a source passes into the melt and the potential health hazard to employees and the public have added further impetus to the development of monitoring systems. Early attempts at scrap monitoring could detect some radiation, but testing with real life situations showed them to be virtually incapable of detecting shielded sources of radioactivity in incoming vehicles. More sophisticated detector technology and the development of advanced software made useful by more powerful microprocessors led to successive generations of monitoring systems with order-of-magnitude improvement in detection capability. The next generation includes larger detectors and more complex algorithms offering further improvement in truck and rail car monitoring. Complete solutions require monitoring at additional locations within the site, such as the charge bucket and conveyor lines, and at the scrap processor's site

Results of chemical decontamination of DOE`s uranium-enrichment scrap metal

Energy Technology Data Exchange (ETDEWEB)

Levesque, R.G.

1997-02-01

The CORPEX{reg_sign} Nuclear Decontamination Processes were used to decontaminate representative scrap metal specimens obtained from the existing scrap metal piles located at the Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. In September 1995, under contract to Lockheed Martin Energy Systems, MELE Associates, Inc. performed the on-site decontamination demonstration. The decontamination demonstration proved that significant amounts of the existing DOE scrap metal can be decontaminated to levels where the scrap metal could be economically released by DOE for beneficial reuse. This simple and environmentally friendly process can be used as an alternative, or in addition to, smelting radiologically contaminated scrap metal.

Effects of Particle Size and Cement Replacement of LCD Glass Powder in Concrete

Directory of Open Access Journals (Sweden)

Seong Kyum Kim

2017-01-01

Full Text Available The high quality liquid crystal display (LCD processing waste glass (LPWG generated from the manufacturing process of Korea’s LCD industries, having the world’s highest technological level and production, was finely ground into particles smaller than cement particles (higher fineness than OPC to verify their applicability and performance as a replacement for cement. For a concrete mix having a W/B ratio of 0.44, cement was replaced with LPWG glass powder (LGP at ratios of 5, 10, 15, and 20% (LGP12 and 5 and 10% (LGP5 according to the particle size to prepare test cylinder specimens, which were tested with respect to air contents, slump in fresh concrete, and compressive strength and splitting tensile strength of hardened concrete. The microstructure of the concrete specimens was analyzed through Scanning Electron Microscopy (SEM, Energy Dispersive X-ray (EDX, and a Mercury Intrusion Porosimetry (MIP. Replacement of cement with LGP for cement could effectively decrease the quantity of cement used due to the excellent performance of LGP. It may positively contribute to the sustainable development of the cement industry as well as waste recycling and environment conservation on a national scale.

Analysis of disposition alternatives for radioactively contaminated scrap metal

International Nuclear Information System (INIS)

Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

1997-01-01

Millions of tonnes of slightly radioactive, scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are to either develop a regulatory process for decontamination and recycling that will safeguard human health or to dispose of the scrap and replace the metal stocks. To evaluate the alternatives, we estimate quantities of scrap arising from nuclear power plant decommissioning, evaluate potential price impacts of recycling on regional markets, and assess the health and environmental impacts of the management alternatives. We conclude that decontaminating and recycling the scrap is the superior alternative

A Comparative Study of Production of Glass Microspheres by using Thermal Process

Science.gov (United States)

Lee, May Yan; Tan, Jully; Heng, Jerry YY; Cheeseman, Christopher

2017-06-01

Microspheres are spherical particles that can be distinguished into two categories; solid or hollow. Microspheres typical ranges from 1 to 200 μm in diameter. Microsphere are made from glass, ceramic, carbon or plastic depending on applications. Solid glass microsphere is manufactured by direct burning of glass powders while hollow glass microspheres is produced by adding blowing agent to glass powder. This paper presented the production of glass microspheres by using the vertical thermal flame (VTF) process. Pre-treated soda lime glass powder with particle sized range from 90 to 125μm was used in this work. The results showed that glass microspheres produced by two passes through the flame have a more spherical shape as compared with the single pass. Under the Scanning Electron Microscope (SEM), it is observed that there is a morphology changed from uneven surface of glass powders to smooth spherical surface particles. Qualitative analysis for density of the pre-burned and burned particles was performed. Burned particles floats in water while pre-burned particles sank indicated the change of density of the particles. Further improvements of the VTF process in terms of the VTF set-up are required to increase the transformation of glass powders to glass microspheres.

Radiation survey of aircraft and heavy machinery scrap.

Science.gov (United States)

Idriss, Hajo; Salih, Isam; Gumaa, Elsadig; Yassin, Abbas; Yousif, E H; Abdel Hamid, Saad Eldeen M; Sam, A K

2012-12-01

This study was conducted primarily to survey aircraft and heavy machinery at 30 locations within Khartoum State using handheld radiation survey meters to detect and identify any radiation sources that might be present and to estimate radiation dose levels. The survey has resulted in detection of 16 sealed sources of (90)Sr and one of (226)Ra in aircraft scrap. Of course, (90)Sr sources are used in military aircraft as temperature sensors while (226)Ra is used for indicating fuel levels. These sources were found intact without spreading radioactivity contamination; however, none was detected in heavy machine scrap. The levels of radiation dose measured at 0.1m from the source fall within the range of 25.1-40.2 μSv/h with an average value of 33.52 ± 4.06 μSv/h. These orphan sources have been separated from the scrap, tested for possible leakage, conditioned and stored in waste management facility. The result of this study has revealed without doubt that the scrap constitute a serious source of public exposure and highlights the importance of legislation making radiation monitoring of scrap in the country mandatory before it is sold to metal industry for reprocessing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of plasma treatment (He/CH4) on glass surface for the reduction of powder flux adhesion in the spray drying process

Science.gov (United States)

Ramlan, Nadiah; Zamri, Nazirah Wahidah Mohd; Maskat, Mohd Yusof; Hoong, Chin Oi; Theng, Lau Yen; Zubairi, Saiful Irwan

2018-04-01

A 50Hz glow discharge He/CH4 plasma was generated and applied for the modification of glass surface to reduce powder adhesion on the wall of spray dryer. The hydrophobicity of the glass samples determined by the water droplet contact angle and adhesion weight on glass, dependent on the CH4 flow rate and plasma exposure time. There was a peak that appeared at 1470 cm-1 on the surface of treated glass indicating the presence of CH3 groups from ATR-FTIR data. Surface morphology analysis using scanning electron microscopy (SEM) showed changes of roughness in the surface-treated glass. The presence of alkyl group (CH3) that deposited on the glass surface is one of the factors that contribute to the increase in the surface roughness. The surface roughness will reflect the value of contact angle where hydrophobic surface are rougher compared to hydrophilic surface. The plasma treatment could enhance the value of the contact angle and thus reduced the adhesion on the spray dryer glass surface.

Glass-Graphite Composite Materials

International Nuclear Information System (INIS)

Mayzan, M.Z.H.; Lloyd, J.W.; Heath, P.G.; Stennett, M.C.; Hyatt, N.C.; Hand, R.J.

2016-01-01

A summary is presented of investigations into the potential of producing glass-composite materials for the immobilisation of graphite or other carbonaceous materials arising from nuclear power generation. The methods are primarily based on the production of base glasses which are subsequently sintered with powdered graphite or simulant TRISO particles. Consideration is also given to the direct preparation of glass-graphite composite materials using microwave technology. Production of dense composite wasteforms with TRISO particles was more successful than with powdered graphite, as wasteforms containing larger amounts of graphite were resistant to densification and the glasses tried did not penetrate the pores under the pressureless conditions used. Based on the results obtained it is concluded that the production of dense glassgraphite composite wasteforms will require the application of pressure. (author)

Catalytic extraction processing of contaminated scrap metal

International Nuclear Information System (INIS)

Griffin, T.P.; Johnston, J.E.

1994-01-01

The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP's off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described

Bioleaching of electronic scrap by mixed culture of moderately thermophilic microorganisms

Science.gov (United States)

Ivǎnuş, D.; ǎnuş, R. C., IV; Cǎlmuc, F.

2010-06-01

A process for the metal recovery from electronic scrap using bacterial leaching was investigated. A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainages (AMDs) samples collected from several sulphide mines in Romania, and the bioleaching of electronic scrap was conducted both in shake flask and bioreactor. The results show that in the shake flask, the mixture can tolerate 50 g/L scrap after being acclimated to gradually increased concentrations of scrap. The copper extraction increases obviously in bioleaching of scrap with moderately thermophilic microorganisms supplemented with 0.4 g/L yeast extract at 180 r/min, 74% copper can be extracted in the pulp of 50 g/L scrap after 20 d. Compared with copper extractions of mesophilic culture, unacclimated culture and acclimated culture without addition of yeast extract, that of accliniated culture with addition of yeast extract is increased by 53%, 44% and 16%, respectively. In a completely stirred tank reactor, the mass fraction of copper and total iron extraction reach up to 81% and 56%, respectively. The results also indicate that it is necessary to add a large amount of acid to the pulp to extract copper from electronic scrap effectively.

Release of Radioactive Scrap Metal/Scrap Metal (RSM/SM) at Nevada Test Site (NTS)

International Nuclear Information System (INIS)

1993-01-01

Reynolds Electrical and Engineering Company, Inc. (REECo) is the prime contractor to the US Department of Energy (DOE) in providing service and support for NTS operations. Mercury Base Camp is the main control point for the many forward areas at NTS, which covers 1,350 square miles. The forward areas are where above-ground and underground nuclear tests have been performed over the last 41 years. No metal (or other material) is returned to Mercury without first being tested for radioactivity. No radioactive metals are allowed to reenter Mercury from the forward areas, other than testing equipment. RAMATROL is the monitor check point. They check material in various ways, including swipe tests, and have a large assortment of equipment for testing. Scrap metal is also checked to address Resource Conservation and Recovery Act concerns. After addressing these issues, the scrap metals are categorized. Federal Property Management Regulations (FPMR) are followed by REECo. The nonradioactive scrap material is sold through the GSA on a scheduled basis. Radioactive scrap metal are presently held in forward areas where they were used. REECo has gained approval of their Nevada Test Site Defense Waste Acceptance Criteria, Certification, and Transfer Requirements, NVO-325 application, which will allow disposal on site, when RSM is declared a waste. The guideline that REECo uses for release limits is DOE Order 5480.11, Radiation Protection for Occupational Works, Attachment 2, Surface Radioactivity Guides, of this order, give release limits for radioactive materials. However, the removal of radioactive materials from NTS require approval by DOE Nevada Operations Office (DOE/NV) on a case-by-case basis. Requirements to consider before removal are found in DOE Order 5820.2A, Radioactive Waste Management

Contaminated scrap metal management on the Oak Ridge Reservation

International Nuclear Information System (INIS)

Hayden, H.W.; Stephenson, M.J.; Bailey, J.K.; Weir, J.R.; Gilbert, W.C.

1993-01-01

Large quantities of scrap metal are accumulating at the various Department of Energy (DOE) installations across the country as a result of ongoing DOE programs and missions in concert with present day waste management practices. DOE Oak Ridge alone is presently storing around 500,000 tons of scrap metal. The local generation rate, currently estimated at 1,400 tons/yr, is expected to increase sharply over the next couple of years as numerous environmental restoration and decommissioning programs gain momentum. Projections show that 775,000 tons of scrap metal could be generated at the K-25 Site over the next ten years. The Y-12 Plant and Oak Ridge National Laboratory (ORNL) have similar potentials. The history of scrap metal management at Oak Ridge and future challenges and opportunities are discussed

Y-12 old salvage yard scrap metal characterization study

International Nuclear Information System (INIS)

Anderson, L.M.; Melton, S.G.; Shaw, S.S.

1993-11-01

The purpose of the Y-12 Old Salvage Yard scrap metal Characterization Study is to make conservative estimates of the quantities of total uranium and the wt % 235 U contained in scrap metal. The original project scope included estimates of thorium, but due to the insignificant quantities found in the yards, thorium was excluded from further analysis. Metal in three of the four Y-12 scrap metal yards were characterized. The scrap metal yard east of the PIDAS fence is managed by the Environmental Restoration Program and therefore was not included in this study. For all Y-12 Plant scrap metal shipments, Waste Transportation, Storage, and Disposal (WTSD) personnel must complete a Request for Authorization to Ship Nuclear Materials, UCN-16409, which requires the grams of total uranium, the wt % 235 U, and the grams of 235 U contained in the shipment. This information is necessary to ensure compliance with Department of Transportation regulations, as well as to ensure that the receiving facility is adhering to its operating license. This characterization study was designed to provide a technical basis for determining these necessary radioactive quantities

Structural analysis and thermal behavior of diopside-fluorapatite-wollastonite-based glasses and glass-ceramics.

Science.gov (United States)

Kansal, Ishu; Tulyaganov, Dilshat U; Goel, Ashutosh; Pascual, Maria J; Ferreira, José M F

2010-11-01

Glass-ceramics in the diopside (CaMgSi2O6)-fluorapatite (Ca5(PO4)3F)-wollastonite (CaSiO3) system are potential candidates for restorative dental and bone implant materials. The present study describes the influence of varying SiO2/CaO and CaF2/P2O5 molar ratio on the structure and thermal behavior of glass compositions in the CaO-MgO-SiO2-P2O5-Na2O-CaF2 system. The structural features and properties of the glasses were investigated by nuclear magnetic resonance (NMR), infrared spectroscopy, density measurements and dilatometry. Sintering and crystallization behavior of the glass powders were studied by hot-stage microscopy and differential thermal analysis, respectively. The microstructure and crystalline phase assemblage in the sintered glass powder compacts were studied under non-isothermal heating conditions at 825 °C. X-ray diffraction studies combined with the Rietveld-reference intensity ratio (R.I.R) method were employed to quantify the amount of amorphous and crystalline phases in the glass-ceramics, while scanning electron microscopy was used to shed some light on the microstructure of resultant glass-ceramics. An increase in CaO/SiO2 ratio degraded the sinterability of the glass powder compacts, resulting in the formation of akermanite as the major crystalline phase. On the other hand, an increase in P2O5/CaF2 ratio improved the sintering behavior of the glass-ceramics, while varying the amount of crystalline phases, i.e. diopside, fluorapatite and wollastonite. Copyright © 2010. Published by Elsevier Ltd.

Modelling and Characterization of Effective Thermal Conductivity of Single Hollow Glass Microsphere and Its Powder.

Science.gov (United States)

Liu, Bing; Wang, Hui; Qin, Qing-Hua

2018-01-14

Tiny hollow glass microsphere (HGM) can be applied for designing new light-weighted and thermal-insulated composites as high strength core, owing to its hollow structure. However, little work has been found for studying its own overall thermal conductivity independent of any matrix, which generally cannot be measured or evaluated directly. In this study, the overall thermal conductivity of HGM is investigated experimentally and numerically. The experimental investigation of thermal conductivity of HGM powder is performed by the transient plane source (TPS) technique to provide a reference to numerical results, which are obtained by a developed three-dimensional two-step hierarchical computational method. In the present method, three heterogeneous HGM stacking elements representing different distributions of HGMs in the powder are assumed. Each stacking element and its equivalent homogeneous solid counterpart are, respectively, embedded into a fictitious matrix material as fillers to form two equivalent composite systems at different levels, and then the overall thermal conductivity of each stacking element can be numerically determined through the equivalence of the two systems. The comparison of experimental and computational results indicates the present computational modeling can be used for effectively predicting the overall thermal conductivity of single HGM and its powder in a flexible way. Besides, it is necessary to note that the influence of thermal interfacial resistance cannot be removed from the experimental results in the TPS measurement.

Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

Science.gov (United States)

Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

2016-03-15

In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

CHANGING THE LANDSCAPE--LOW-TECH SOLUTIONS TO THE PADUCAH SCRAP METAL REMOVAL PROJECT ARE PROVIDING SAFE, COST-EFFECTIVE REMEDIATION OF CONTAMINATED SCRAP YARDS

International Nuclear Information System (INIS)

Watson, Dan; Eyman, Jeff

2003-01-01

Between 1974 and 1983, contaminated equipment was removed from the Paducah Gaseous Diffusion Plant (PGDP) process buildings as part of an enrichment process upgrade program. The upgrades consisted of the dismantlement, removal, and on-site storage of contaminated equipment, cell components, and scrap material (e.g., metal) from the cascade facilities. Scrap metal including other materials (e.g., drums, obsolete equipment) not related to this upgrade program have thus far accumulated in nine contiguous radiologically-contaminated and non-contaminated scrap yards covering 1.05E5 m2 (26 acres) located in the northwestern portion of the PGDP. This paper presents the sequencing of field operations and methods used to achieve the safe removal and disposition of over 47,000 tonnes (53,000 tons) of metal and miscellaneous items contained in these yards. The methods of accomplishment consist of mobilization, performing nuclear criticality safety evaluations, moving scrap metal to ground level, inspection and segregation, sampling and characterization, scrap metal sizing, packaging and disposal, and finally demobilization. Preventing the intermingling of characteristically hazardous and non-hazardous wastes promotes waste minimization, allowing for the metal and materials to be segregated into 13 separate waste streams. Low-tech solutions such as using heavy equipment to retrieve, size, and package scrap materials in conjunction with thorough planning that integrates safe work practices, commitment to teamwork, and incorporating lessons learned ensures that field operations will be conducted efficiently and safely

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

OFFGAS GENERATION FROM THE DISPOSITION OF SCRAP PLUTONIUM BY VITRIFICATION SIMULANT TESTS

International Nuclear Information System (INIS)

Zamecnik, J; Patricia Toole, P; David Best, D; Timothy Jones, T; Donald02 Miller, D; Whitney Thomas, W; Vickie Williams, V

2008-01-01

The Department of Energy Office of Environmental Management is supporting R and D for the conceptual design of the Plutonium Disposition Project at the Savannah River Site in Aiken, SC to reduce the attractiveness of plutonium scrap by fabricating a durable plutonium oxide glass form and immobilizing this form within the high-level waste glass prepared in the Defense Waste Processing Facility. A glass formulation was developed that is capable of incorporating large amounts of actinides as well as accommodating many impurities that may be associated with impure Pu feed streams. The basis for the glass formulation was derived from commercial glasses that had high lanthanide loadings. A development effort led to a Lanthanide BoroSilicate (LaBS) glass that accommodated significant quantities of actinides, tolerated impurities associated with the actinide feed streams and could be processed using established melter technologies. A Cylindrical Induction Melter (CIM) was used for vitrification of the Pu LaBS glass. Induction melting for the immobilization of americium and curium (Am/Cm) in a glass matrix was first demonstrated in 1997. The induction melting system was developed to vitrify a non-radioactive Am/Cm simulant combined with a glass frit. Most of the development of the melter itself was completed as part of that work. This same melter system used for Am/Cm was used for the current work. The CIM system used consisted of a 5 inch (12.7 cm) diameter inductively heated platinum-rhodium (Pt-Rh) containment vessel with a control system and offgas characterization. Scrap plutonium can contain numerous impurities including significant amounts of chlorides, fluorides, sodium, potassium, lead, gallium, chromium, and nickel. Smaller amounts of additional elements can also be present. The amount of chlorides present is unusually high for a melter feed. In commercial applications there is no reason to have chloride at such high concentrations. Because the melter operates at

Ceramic grade (U,Pu)O2 powder fabrication

International Nuclear Information System (INIS)

Cristallini, O.A.; Villegas de Maroto, Marina; De Pino, J.I.; Osuna, H.A.

1980-01-01

Ceramic grade UO 2 powder was obtained by the homogeneous precipitation method. This procedure was afterwards applied to the fabrication of ceramic grade (U,Pu)O 2 powders, and mixed oxide powders with Pu content ranging from 0.7 to 16% were obtained. The obtainment of mixed ceramic oxides as well as the recuperation of fabrication scraps were developed in three steps: 1)study of the process of homogeneous precipitation of ammonium diuranate (ADU); 2) co-precipitation of ADU/PuO 2 .H 2 O for Pu concentrations of 0.6 and 6.8; 3) the thermal conditioning to mixed oxide (U,Pu)O 2 powders. The experimental procedure involves the following steps: preparation of the PuO 2 (NO 3 ) 4 solution; co-precipitation of the PuO 2 (NO 3 ) 2 solution with an UO 2 (NO 3 ) 2 solution; filtration and drying of the precipitate, thermal treatment and finally, mixing, pressing and sintering of the (U,Pu)O 2 and Nukem UO 2 powder with a 0. of zinc stearate. Different controls were made by means of physical, chemical and ceramographic tests. This method can be used for the fabrication of fast reactor fuels or, previous mechanical dispersion in UO 2 powder, for the fabrication of thermal reactors fuels. (M.E.L.) [es

Heterogeneities in nuclear waste glass

International Nuclear Information System (INIS)

Ladirat, Ch.

1997-01-01

The industrial vitrification of high level radioactive wastes is a 2 stage process. During the first stage, the concentrated solution is heated in a spinning resistance oven at the temperature of 400 Celsius degrees till evaporation and calcination. The second stage begins when the dry residue falls into a melting pot that is maintained at a temperature of 1100-1150 Celsius degrees. Glass fretting is added and the glass is elaborated through the fusion of the different elements present in the melting pot. Heterogeneities in the glass may be associated to: - the presence in the solution to vitrify of insoluble elements from the dissolution of the fuel (RuO 2 , Rh, Pd), - the presence of minuscule metal scraps (Zr) that have been produced during the cutting of the fuel element, - the failures to conform to the technical specifications of the vitrification process, for instance, temperatures or flow rates when introducing the different elements in the melting pot. (A.C.)

The Study for Recycling NORM - Contaminated Steel Scraps from Steel Industry

International Nuclear Information System (INIS)

Tsai, K. F.; Lee, Y. S.; Chao, H. E.

2003-01-01

Since 1994, most of the major steel industries in Taiwan have installed portal monitor to detect the abnormal radiation in metal scrap feed. As a result, the discovery of NORM (Naturally Occurring Radioactive Material) has increased in recent years. In order to save the natural resources and promote radiation protection, an experimental melting process for the NORM contaminated steel scraps was carried out by the Institute of Nuclear Energy Research (INER) Taiwan, ROC. The experimental melting process has a pretreatment step that includes a series of cutting and removal of scales, sludge, as well as combustible and volatile materials on/in the steel scraps. After pretreatment the surface of the steel scraps are relatively clean. Then the scraps are melted by a pilot-type induction furnace. This experiment finally produced seven ingots with a total weight of 2,849 kg and 96.8% recovery. All of the surface dose rates are of the background values. The activity concentrations of these ingots are also below the regulatory criteria. Thus, these NORM-bearing steel scraps are ready for recycling. This study has been granted by the regulatory authority

Survey on the scrap iron and steel recycling in Thailand and Indonesia; Hatten tojokoku (Tai Indonesia) ni okeru tetsu scrap saiseiyo ni kansuru chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

This report describes the survey results of the scrap iron and steel recycling industries in Thailand and Indonesia. The purpose of this survey is to extract problems obstructing the scrap iron and steel recycling, to recognize the present situation and predict the future situation, and to examine the possibility of international cooperation. As a result of the survey, it was found that the quality of scrap collected in the domestic market is poor as it contains too many impurities for it to be utilized for the manufacture of many higher quality iron and steel products. The actual quantity of domestically collected scrap is too low to support the expected growth in demand in each nation. Current environmental management practices are largely concerned with the construction of wastewater treatment facilities and the extraction of furnace dust. However, the lack of enforcement of environmental regulations does not encourage companies to implement sound environmental practices. Neither government actively promotes and investigates iron and steel recycling in the domestic, commercial or industrial sectors. Collaboration with overseas nations having more advanced iron and steel industries could be helpful to the scrap recycling industry in both nations. 6 figs., 21 tabs.

Foam glass obtained through high-pressure sintering

DEFF Research Database (Denmark)

Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

2018-01-01

Foam glasses are usually prepared through a chemical approach, that is, by mixing glass powder with foaming agents, and heating the mixture to a temperature above the softening point (106.6 Pa s) of the glass. The foaming agents release gas, enabling expansion of the sintered glass. Here, we use...... a physical foaming approach to prepare foam glass. First, closed pores filled with inert gases (He, Ar, or N2) are physically introduced into a glass body by sintering cathode ray tube (CRT) panel glass powder at high gas pressure (5‐25 MPa) at 640°C and, then cooled to room temperature. The sintered bodies...... are subjected to a second heat treatment above the glass transition temperature at atmospheric pressure. This heat treatment causes expansion of the pores due to high internal gas pressure. We found that the foaming ability strongly depends on the gas pressure applied during sintering, and on the kinetic...

Scrapping of student bursaries confirmed.

Science.gov (United States)

Longhurst, Chris

2016-07-27

Student bursaries for nurses will be scrapped from next year, the government has confirmed. Undergraduate nursing and midwifery students in England will now face tuition fees and student loans from August 2017.

Process options and projected mass flows for the HTGR refabrication scrap recovery system

International Nuclear Information System (INIS)

Tiegs, S.M.

1979-03-01

The two major uranium recovery processing options reviewed are (1) internal recovery of the scrap by the refabrication system and (2) transfer to and external recovery of the scrap by the head end of the reprocessing system. Each option was reviewed with respect to equipment requirements, preparatory processing, and material accountability. Because there may be a high cost factor on transfer of scrap fuel material to the reprocessing system for recovery, all of the scrap streams will be recycled internally within the refabrication system, with the exception of reject fuel elements, which will be transferred to the head end of the reprocessing system for uranium recovery. The refabrication facility will be fully remote; thus, simple recovery techniques were selected as the reference processes for scrap recovery. Crushing, burning, and leaching methods will be used to recover uranium from the HTGR refabrication scrap fuel forms, which include particles without silicon carbide coatings, particles with silicon carbide coatings, uncarbonized fuel rods, carbon furnace parts, perchloroethylene distillation bottoms, and analytical sample remnants. Mass flows through the reference scrap recovery system were calculated for the HTGR reference recycle facility operating with the highly enriched uranium fuel cycle. Output per day from the refabrication scrap recovery system is estimated to be 4.02 kg of 2355 U and 10.85 kg of 233 U. Maximum equipment capacities were determined, and future work will be directed toward the development and costing of the scrap recovery system chosen as reference

BNFL Report Glass Formers Characterization

Energy Technology Data Exchange (ETDEWEB)

Schumacher, R.F.

2000-07-27

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. The problems might include arching or ratholing in the silo/hopper. In addition, all of the blends may require consideration for their handling.

BNFL Report Glass Formers Characterization

International Nuclear Information System (INIS)

Schumacher, R.F.

2000-01-01

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. The problems might include arching or ratholing in the silo/hopper. In addition, all of the blends may require consideration for their handling

System for Prevention, Detection and Response to Radioactive Materials in Scrap Metal in Ukraine

Energy Technology Data Exchange (ETDEWEB)

Makarovska, O., E-mail: makarovska@hq.snrc.gov.ua [State Nuclear Regulatory Committee of Ukraine, Kiev (Ukraine)

2011-07-15

The State control system to prevent, detect and respond to cases of radioactive material in scrap metal is functioning in Ukraine. The system includes regulations for the safe and secure management of metal scrap and administrative and technical measures to prevent, detect and respond to cases of radioactive material in scrap metal. The key elements of prevention are the system of licensing and supervision in the sphere of radioactive material use and the State system for inventory, registration and control of radiation sources. Metal scrap management is licensed by the Ministry of Industrial Policy and one of the licence conditions is radiation control of the scrap metal. State supervision of the operations with metal scrap is provided by Ministry of Health and Ministry of Environmental Protection according to the regulation 'State sanitary-ecological standard for metal scrap management'. Specific standards exist for the export of metal scrap. Export consignments are followed by a certificate that proves the radiological safety of the metal. Ukrainian metallurgical plants provide an input radiation control of metal scrap and an output control of the produced metal. Thus, there exists a five barrier system of metal scrap control: border control; exclusion zone perimeter control; metal scrap dealers control; metallurgical plants (input control and output control of produced metal); and export consignments radiological certification. To regain control over orphan sources (including occasional radioactive material in the scrap metal) the 'procedure for interaction of executive authorities and involved legal entities in case of revealing of radiation sources in no legal use' was approved by a Resolution of the Cabinet of Ministers of Ukraine. The investigation of each case with feedback, information of involved bodies, safe and secure storage of restored radioactive material are provided according to this procedure. (author)

Durability of Mortar Made with Fine Glass Powdered Particles

Directory of Open Access Journals (Sweden)

Rosemary Bom Conselho Sales

2017-01-01

Full Text Available Different studies investigate the use of waste glass in Portland cement compounds, either as aggregates or as supplementary cementitious materials. Nevertheless, it seems that there is no consensus about the influence of particle color and size on the behavior of the compounds. This study addresses the influence of cement replacement by 10 and 20% of the colorless and amber soda-lime glass particles sized around 9.5 μm on the performance of Portland cement mortars. Results revealed that the partial replacement of cement could contribute to the production of durable mortars in relation to the inhibition of the alkali-aggregate reaction. This effect was more marked with 20% replacement using amber glass. Samples containing glass microparticles were more resistant to corrosion, in particular those made of colorless glass. The use of colorless and amber glass microparticles promoted a reduction in wear resistance.

40 CFR 63.10885 - What are my management practices for metallic scrap and mercury switches?

Science.gov (United States)

2010-07-01

... minimize the presence of mercury in scrap from end-of-life vehicles. (3) Option for specialty metal scrap... metallic scrap and mercury switches? 63.10885 Section 63.10885 Protection of Environment ENVIRONMENTAL... Affected Sources § 63.10885 What are my management practices for metallic scrap and mercury switches? (a...

Recycled scrap metal and soils/debris with low radioactive contents

International Nuclear Information System (INIS)

Carriker, A.W.

1996-01-01

Two types of large volume bulk shipments of materials with low radioactivity have characteristics that complicate compliance with normal transport regulations. Scrap metal for recycling sometimes contains radioactive material that was not known or identified by the shipper prior to it being offered for transport to a scrap recycle processor. If the radioactive material is not detected before the scrap is processed, radiological and economic problems may occur. If detected before processing, the scrap metal will often be returned to the shipper. Uranium mill-tailings and contaminated soils and debris have created potential public health problems that required the movement of large volumes of bulk material to isolated safe locations. Similarly, old radium processing sites have created contamination problems needing remediation. The US Department of Transportation has issued exemptions to shippers and carriers for returning rejected scrap metal to original shippers. Other exemptions simplify transport of mill-tailings and debris from sites being remediated. These exemptions provide relief from detailed radioassay of the radioactive content in each conveyance as well as relief from the normal requirements for packaging, shipping documents, marking, labelling, and placarding which would be required for some of the shipments if the exemptions were not issued. (Author)

Evaluation of segmented gamma scanner measurements on cans of recoverable scrap

International Nuclear Information System (INIS)

Shull, A.H.; Weber, J.H.; MacMurdo, K.W.; Baker, L.B.

1991-01-01

Savannah River Site (SRS) has had a long-standing concern about the inability to measure recoverable scrap. A segmented gamma scanner (SGS) was evaluated for use in measuring cans of scrap materials. Four scrap cans were selected and re-packaged into containers that could be measured using calorimetry and gamma spectrometry. These scrap cans were later used as working standards for the SGS. In addition, replicate measurements were made on all cans of scrap currently stored with estimated values. Before accepting the SGS measurements on the cans, data from the replicate measurements of the standards and a limited number of process cans were analyzed to determine if there was a significant bias between the SGS and the calorimeter-gamma spectrometer measurements, if the random replication error would be acceptable for accountability, to set control limits for the workings standards, and to determine acceptable differences between replicate measurements. After completing the measurement of all process scrap cans in the inventory, the the final data were analyzed and estimates based on the two sets of data compared. The methodology used to determine the appropriate measurement error model, to estimate the measurement errors, to set control limits, and to determine the significance of the bias will be described as well as a comparison of the error estimates based on the preliminary versus final data

A method and apparatus for the manufacture of glass microspheres adapted to contain a thermonuclear fuel

International Nuclear Information System (INIS)

Budrick, R.G.; Nolen, R.L. Jr.; Solomon, D.E.; King, F.T.

1975-01-01

The invention relates to the manufacture of glass microspheres. It refers to a method according to which a sintered glass-powder, whose particles are calibrated, is introduced into a blow-pipe adapted to project said glass-powder particles into a heated flue, said sintered glass-powder containing a pore-forming agent adapted to expand the glass particles into microspheres which are collected in a chamber situated abode said flue. The method can be applied to the manufacture of microspheres adapted to contain a thermonuclear fuel [fr

State of the art of smelting lead-acid battery scrap

Energy Technology Data Exchange (ETDEWEB)

Melin, A

1977-02-01

A discussion is given of the economic importance of lead recovery and of scrap recycling in the battery industry. Various possibiliies of processing battery scrap, either by direct smelting or by smelting after preparaton are discussed, and the BBU, the Stolberger, and the Tonnolli methods are compared

Management of radiation protection aspects in the recycling of metallurgical scrap: the report of UNECE team of specialists on radioactive contaminated scrap

International Nuclear Information System (INIS)

Deckers, B.

2001-01-01

Complete text of publication follows: In 1999, the United Nations Economic Commission for Europe (UNECE) has created a Team of Specialists on Radioactive Contaminated Metal Scrap: technically qualified representatives of the steel industry, government representatives and competent international organizations representatives have studied the problem of radioactively contaminated scrap and steel, and have proposed solutions in this context acceptable at the international level in order to harmonize the legislation, the systems of measurement of radioactivity, the levels of detection. This team has established a document which will be published by the United Nations, and where good practices on managing radioactive metal scrap are presented, and which also contains numerous recommendations in order to harmonize legislations. The paper presents the content of the document and the main recommendations of the team. (author)

Antibacterial effects and dissolution behavior of six bioactive glasses.

Science.gov (United States)

Zhang, Di; Leppäranta, Outi; Munukka, Eveliina; Ylänen, Heimo; Viljanen, Matti K; Eerola, Erkki; Hupa, Mikko; Hupa, Leena

2010-05-01

Dissolution behavior of six bioactive glasses was correlated with the antibacterial effects of the same glasses against sixteen clinically important bacterial species. Powdered glasses (<45 microm) were immersed in simulated body fluid (SBF) for 48 h. The pH in the solution inside the glass powder was measured in situ with a microelectrode. After 2, 4, 27, and 48 h, the pH and concentration of ions after removing the particles and mixing the SBF were measured with a normal glass pH electrode and ICP-OES. The bacteria were cultured in broth with the glass powder for up to 4 days, after which the viability of the bacteria was determined. The antibacterial effect of the glasses increased with increasing pH and concentration of alkali ions and thus with increased dissolution tendency of the glasses, but it also depended on the bacterium type. The changes in the concentrations of Si, Ca, Mg, P, and B ions in SBF did not show statistically significant influence on the antibacterial property. Bioactive glasses showed strong antibacterial effects for a wide selection of aerobic bacteria at a high sample concentration (100 mg/mL). The antibacterial effects increased with glass concentration and a concentration of 50 mg/mL (SA/V 185 cm(-1)) was required to generate the bactericidal effects. Understanding the dissolution mechanisms of bioactive glasses is essential when assessing their antibacterial effects. Copyright 2009 Wiley Periodicals, Inc.

Foaming of CRT panel glass powder with Na2CO3

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup

melt, while Na2O becomes incorporated into the glass structure. We have quantified the melt expansion through density measurements and the Na2O incorporation is indicated by the decrease of the glass transition temperature (Tg) of the final foam glass. The glass foaming quality depends on the foaming......Recycling of cathode ray tube (CRT) glass remains a challenging task. The CRT glass consists of four glass types fused together: Funnel-, neck-, frit- and panel glass. The three former glasses contain toxic lead oxide, and therefore have a low recycling potential. The latter on the other hand...... is lead-free, but since barium and strontium oxide are present, panel glass is incompatible with most common recycling methods. However, foam glass production is a promising approach for the recycling of panel glass waste, since the process parameters can be changed according to the glass waste...

46 CFR Sec. 12 - Disposition of removed equipment and scrap.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Disposition of removed equipment and scrap. Sec. 12... CONTRACT-NSA-LUMPSUMREP Sec. 12 Disposition of removed equipment and scrap. (a) Article 8 of the NSA-LUMPSUMREP Contract provides that any ship equipment, fuel, lube oil, supplies, stores, furniture, fixtures...

Crystallization Kinetics of Barium and Strontium Aluminosilicate Glasses of Feldspar Composition

Science.gov (United States)

Hyatt, Mark J.; Bansal, Narottam P.

1994-01-01

Crystallization kinetics of BaO.Al2O3.2SiO2 (BAS) and SrO.Al2O3.2SiO2 (SAS) glasses in bulk and powder forms have been studied by non-isothermal differential scanning calorimetry (DSC). The crystal growth activation energies were evaluated to be 473 and 451 kJ/mol for bulk samples and 560 and 534 kJ/mol for powder specimens in BAS and SAS glasses, respectively. Development of crystalline phases on thermal treatments of glasses at various temperatures has been followed by powder x-ray diffraction. Powder samples crystallized at lower temperatures than the bulk and the crystallization temperature was lower for SAS glass than BAS. Crystallization in both glasses appeared to be surface nucleated. The high temperature phase hexacelsian, MAl2Si2O8 (M = Ba or Sr), crystallized first by nucleating preferentially on the glass surface. Also, monoclinic celsian does not nucleate directly in the glass, but is formed at higher temperatures from the transformation of the metastable hexagonal phase. In SAS the transformation to monoclinic celsian occurred rapidly after 1 h at 1100 C. In contrast, in BAS this transformation is sluggish and difficult and did not go to completion even after 10 h heat treatment at 1400 C. The crystal growth morphologies in the glasses have been observed by optical microscopy. Some of the physical properties of the two glasses are also reported.

Preparation techniques for ceramic waste form powder

International Nuclear Information System (INIS)

Hash, M.C.; Pereira, C.; Lewis, M.A.

1997-01-01

The electrometallurgical treatment of spent nuclear fuels result in a chloride waste salt requiring geologic disposal. Argonne National Laboratory (ANL) is developing ceramic waste forms which can incorporate this waste. Currently, zeolite- or sodalite-glass composites are produced by hot isostatic pressing (HIP) techniques. Powder preparations include dehydration of the raw zeolite powders, hot blending of these zeolite powders and secondary additives. Various approaches are being pursued to achieve adequate mixing, and the resulting powders have been HIPed and characterized for leach resistance, phase equilibria, and physical integrity

Primary Raw Materials for Steelmakers: Scrap and Pig Iron

Directory of Open Access Journals (Sweden)

Cristina Bumbac

2011-10-01

Full Text Available Most of the daily steel we so much need is obtained now in electric furnaces, for which the main raw material is scrap. The scrap market is a very sensitive one, depending very much on internal collect, exports and imports, the market of steel and freight. Commerce with scrap is one of the most intense among all the countries of the world and covers all the routes and regions. Every ten years or so importers become exporters and vice versa, due to the period of life of the metallic products. For example, China was for the last 10 years one of the biggest importers (after Turkey, which is number one in importers' hierarchy, but prognoses tell that in 2-3 years China might become self-sufficient due to the investments which began some 20 years ago. USA was one of the largest exporters, but some 3 years ago some analysts advanced the idea that it may become a net importer (it didn't happened, though. The scrap market is not only important, it is also very interesting, with twisted evolutions and volatile prices in some periods.

Crystallization behaviors and seal application of basalt based glass-ceramics

Science.gov (United States)

Ateş, A.; Önen, U.; Ercenk, E.; Yılmaz, Ş.

2017-02-01

Basalt based glass-ceramics were prepared by conventional melt-quenching technique and subsequently converted to glass-ceramics by a controlled nucleation and crystallization process. Glass materials were obtained by melt at 1500°C and quenched in cold water. The powder materials were made by milling and spin coating. The powders were applied on the 430 stainless steel interconnector material, and heat treatment was carried out. The interface characteristics between the glass-ceramic layer and interconnector were investigated by using X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The results showed that the basalt base glass-ceramic sealant material exhibited promising properties to use for SOFC.

Alumina particle degradation during solid particle impact on glass

NARCIS (Netherlands)

Slikkerveer, P.J.; Veld, in 't H.; Verspui, M.A.; With, de G.; Reefman, D.

2000-01-01

Particle degradation limits the reuse of powders in industrial powder-blast processes. In this paper the degradation behavior of Al2O3 powder is studied during erosion of glass substrates. Three techniques were used on original and multiply used powders: particle size measurements, single particle

Oxycarbonitride glass formation by melt solidification

Energy Technology Data Exchange (ETDEWEB)

Imon, M M; Risbud, S H

1986-04-01

Experimental results are presented from the synthesis and characterization of multianion oxycarbonitride glasses composed of MgSiAlON glass powders with SiC additions of 5, 10, or 15 wt pct. Nitrogen additions to the oxide MgO-Al2O3-SiO2 glasses increased devitrification resistance, but carbon additions to MgSiAlON glasses promote crystal nucleation. These properties are relevant to the oxycarbonitride glasses use in refractory glass-ceramic and ceramic-ceramic composite systems with good elevated temperature performance. 9 references.

High Value Scrap Tire Recycle

Energy Technology Data Exchange (ETDEWEB)

Bauman, B. D.

2003-02-01

The objectives of this project were to further develop and scale-up a novel technology for reuse of scrap tire rubber, to identify and develop end uses for the technology (products), and to characterize the technology's energy savings and environmental impact.

Management of radioactive scrap metal at SCK-CEN

International Nuclear Information System (INIS)

Noynaert, L.; Klein, M.; Cornelissen, R.; Ponnet, M.

2000-01-01

The environmental concern and public perception as well as the steadily increase of the conditioning and disposal costs are pushing the nuclear sector to minimise the amount of radioactive waste. Hence it is a strong incentive to prefer the management option 'recycling and reuse' instead of the option 'disposal and replacement'. The 'recycling and reuse' option requires the availability of decontamination techniques as well as measuring techniques allowing to prove that the release criteria are met. Therefore SCK-CEN has now two decontamination installations for scrap metal on its own site. One installation uses a wet abrasive technique while the other one uses a chemical process based on the Ce 4+ . These two installations, combined with the use of foundries for free release or for radioactive scrap metal recycling are now common practices at SCK-CEN and will allow to reduce the metallic waste to 10% of the metallic scrap production and the costs at least by a factor 2.5. (author)

Complex deformation routes for direct recycling aluminium alloy scrap via industrial hot extrusion

Science.gov (United States)

Paraskevas, Dimos; Kellens, Karel; Kampen, Carlos; Mohammadi, Amirahmad; Duflou, Joost R.

2018-05-01

This paper presents the final results of an industrial project, aiming for direct hot extrusion of wrought aluminium alloy scrap at an industrial scale. Two types of complex deformation/extrusion routes were tested for the production of the same profile, starting from AA6060 scrap in form of machining chips. More specifically scrap-based billets were extruded through: a 2-porthole and a 4-porthole die-set, modified for enhanced scrap consolidation and grain refinement. For comparison reasons, cast billets of the same alloy were extruded through the modified 2-porthole die set. The tensile testing results as well as microstructural investigations show that the 4-porthole extrusion route further improves scrap consolidation compared to the 2-porthole die output. The successful implementation of solid state recycling, directly at industrial level, indicates the technological readiness level of this research.

Influence of spark plasma sintering parameters on the mechanical properties of Cu{sub 50}Zr{sub 45}Al{sub 5} bulk metallic glass obtained using metallic glass powder

Energy Technology Data Exchange (ETDEWEB)

Cardinal, S. [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Pelletier, J.M., E-mail: jean-marc.pelletier@insa-lyon.fr [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Qiao, J.C. [School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi’an 710072 (China); Bonnefont, G. [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Xie, G. [Institute for Materials Research, Tohoku University, Sendai (Japan)

2016-11-20

Gas atomized Cu{sub 50}Zr{sub 45}Al{sub 5} amorphous powder was densified by spark plasma sintering, in order to obtain bulk metallic glasses with larger size than that obtained by the conventional casting strategy. The influence of different parameters was investigated: sintering temperature, isothermal holding time as well as size of the specimens. After optimization of the processing parameters, dense and amorphous specimens were elaborated with a diameter up to 30 mm. Thermal stability and mechanical properties of consolidated samples are similar to those of Cu{sub 50}Zr{sub 45} Al{sub 5} cast alloy. A hardness of 535 HV and a compressive strength of 1600 MPa have been obtained. Fractographic investigation indicated an intergranular rupture mode which leads to lower toughness compared to as the cast material, but for these samples the size is limited to 3 mm. However an increase in applied pressure (from 90 MPa to 1 GPa) induces a significant improvement in bonding between powder particles.

Waste E-glass particles used in cementitious mixtures

International Nuclear Information System (INIS)

Chen, C.H.; Huang, R.; Wu, J.K.; Yang, C.C.

2006-01-01

The properties of concretes containing various waste E-glass particle contents were investigated in this study. Waste E-glass particles were obtained from electronic grade glass yarn scrap by grinding to small particle size. The size distribution of cylindrical glass particle was from 38 to 300 μm and about 40% of E-glass particle was less than 150 μm. The E-glass mainly consists of SiO 2 , Al 2 O 3 , Ca O and MgO, and is indicated as amorphous by X-ray diffraction (XRD) technique. Compressive strength and resistance of sulfate attack and chloride ion penetration were significantly improved by utilizing proper amount of waste E-glass in concrete. The compressive strength of specimen with 40 wt.% E-glass content was 17%, 27% and 43% higher than that of control specimen at age of 28, 91 and 365 days, respectively. E-glass can be used in concrete as cementitious material as well as inert filler, which depending upon the particle size, and the dividing size appears to be 75 μm. The workability decreased as the glass content increased due to reduction of fineness modulus, and the addition of high-range water reducers was needed to obtain a uniform mix. Little difference was observed in ASR testing results between control and E-glass specimens. Based on the properties of hardened concrete, optimum E-glass content was found to be 40-50 wt.%

Influence of the glass-calcium carbonate mixture's characteristics on the foaming process and the properties of the foam glass

DEFF Research Database (Denmark)

König, Jakob; Petersen, Rasmus Rosenlund; Yue, Yuanzheng

2014-01-01

We prepared foam glasses from cathode-ray-tube panel glass and CaCO3 as a foaming agent. We investigated the influences of powder preparation, CaCO3 concentration and foaming temperature and time on the density, porosity and homogeneity of the foam glasses. The results show that the decomposition...

Economic aspects of recycling U.S. Department of Energy radioactive scrap metal

International Nuclear Information System (INIS)

Harrop, J.; Numark, N.; MacKinney, J.

1995-01-01

The U.S. Department of Energy (DOE) has substantial quantities of scrap metal contaminated with low-levels of radioactivity. What is more important, current DOE Decommissioning and Dismantlement (D and D) plans will generate even more radioactive scrap metal. Disposition of this radioactive scrap metal could result in substantial costs to the DOE, but if certain options are exercised, could result in an economic gain. This paper outlines five basic options the DOE could follow for disposition of its radioactive scrap metal, and then examines the economic consequences of each option. A cost-benefit analysis was used to evaluate each of the five options. Real costs, derived from DOE studies and private industry, formed the basis for all analysis. These include transportation, packaging, processing (melt-refining) prices charged by industry, and burial fees and scrap metal storage facility operating and surveillance costs faced by the DOE. Other potential costs, such as the avoided costs of mining, and other less-well defined factors are assumed imbedded in the prices charged by industry for processing radioactive scrap metal. The results of this analysis show that burial cost is the most significant factor to consider in deciding which RSM disposition option to pursue. Moderate variations in burial costs can dramatically change the outcome of the cost-benefit analysis. (author)

The development of technology for recycling of electronic scrap

Energy Technology Data Exchange (ETDEWEB)

Yu, Hyo-Shin; Kim, Won-Baek; Sohn, Yong-Uhn [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

1999-12-01

Electronic devices, especially computer becomes an essential tools for home and industries entering the information era. The number of computers exceed over 100 million, hence, the amount of end of life(EOL) computer and electronic scrap is increasing. These wastes and scraps include products rejected from manufacturing processes and obstacle computers. Owing to a short life cycle of electronic products and rapid growth of electronic industries, the number of domestic EOL computers goes beyond a million and its disposal causes an environmental problems. Therefore, this recycling is considered to play an important role from the viewpoint of environmental preservation as well as reusable resources. The process development for the recovery of valuable materials and minimization of waste from electronic scrap has been carried out. In the first year of three year project, physical separation such as shredding, crushing, and magnetic separation is established to reclaim valuable materials effectively. Then, hydro- and pyrometallurgical processes are employed to recover valuable metals from electronic scrap. First, metallic and nonmetallic portion are separated from PCBs by a newly designed shredder to prevent hazardous organic materials from further chemical treatment. The optimum conditions for each unit process were found in terms of separation ratio, energy consumption, recovery rate, etc. (author). 92 refs., 24 tabs., 39 figs.

Problems concerned with scrap metal monitoring at borders

International Nuclear Information System (INIS)

Duftschmid, K.E.

1997-01-01

Since the early 1980's numerous incidents have been reported in which radioactive material or empty labelled containers for radioactive sources have been found in scrap metal. Apart from the potential health hazard to employees and the general public resulting costs for decontamination, shutdown of production and waste of products already amounted to multi-million dollar figures. Since the opening of the ''iron border'' in Europe, incidents of illicit trafficking of radioactive sources across borders and contamination of scrap metal imported from the former ''Eastern Countries'' have considerably increased, as a result of the lack of a suitable radiation protection infrastructure in some of these countries. This initiated monitoring of scrap metal transports at the borders of several European countries, such as Austria, Finland, Germany and Italy. Up to now neither universally accepted clearance levels for scrap contamination, nor an agreed standardised procedure for its control exist, although the IAEA as well as the European Commission have proposed some recommendations. As a pragmatic solution for border monitoring it is suggested to apply, as practical clearance level, a dose rate on the outside of the vehicle in the order of 0,1 μSv/h, which is approximately equivalent to double natural environmental background. This dose rate would correspond to an activity concentration for 60 Co in the order of 1 kBq/kg and therefore be in a tolerable range, even in view of products coming in close contact with the public. (author)

Comparative Study on Carbonated and Non-Carbonated Recycled Aggregate Concrete with Glass Powder as Partial Replacement for OPC

Directory of Open Access Journals (Sweden)

Abhishek Patil

2017-12-01

Full Text Available Recycled aggregates (RA possess the ability to be recycled, if undesirable properties are counteracted viz, porous mortar attached to it, with high water absorption and low density, this technique, accelerated carbonation can be one such to technique to counteract undesirable properties of RA, replacement of 20% of cement by glass powder assists in reducing w/c ratio[1][6] when used in concrete[2] suppress ASR reaction[1], this paper explains a new possibility of recycling concrete, work done and findings for improvising Recycled aggregate concrete (RAC and exploring the feasibility for use of RA in the near future.

Recovery of gold from electronic scrap by hydrometallurgical processes

Energy Technology Data Exchange (ETDEWEB)

Lee, Churl Kyoung; Rhee, Kang-In [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of); Sohn, Hun Joon [Seoul National University, Seoul (Korea, Republic of)

1997-09-30

A series of processes has been developed to recover the gold from electronic scrap containing about 200{approx}600 ppm Au. First, mechanical beneficiation including shredding, crushing and screening was employed. Results showed that 99 percent of gold component leaves in the fraction of under 1 mm of crushed scrap and its concentration was enriched to about 800 ppm without incineration. The crushed scrap was leached in 50% aqua regia solution and gold was completely dissolved at 60 deg. C within 2 hours. Other valuable metals such as silver, copper, nickel and iron were also dissolved. The resulting solution was boiled to remove nitrous compounds in the leachate. Finally, a newly designed electrolyzer was tested to recover the gold metal. More than 99% of gold and silver were recovered within an hour by electrowinning process. (author). 10 refs., 5 tabs., 6 figs.

Radioactive sources and contaminated materials in scrap: monitoring, detection and remedial actions

International Nuclear Information System (INIS)

Gallini, R.; Berna, V.; Bonora, A.; Santini, M.

1999-01-01

The scrap recycling in steel and other metal mills represents one of the most relevant activities in the Province of Brescia (Lombardy, Italy). In our Province more than 20 million tonnes of metal scrap are recycled every year by a melting process. Since 1990, many accidents which took place were caused by the unwanted melting of radioactive sources, that were probably hidden in metal scrap. In 1993, the Italian Government stated directives to monitor metal scrap imported from non-EC countries because of the suspicion of the illegal traffic of radioactive materials. In 1996, a law imposed the control of all metal scrap, regardless of their origins. Since 1993, our staff have controlled thousands of railway wagons and trucks. Approximately a hundred steel mills and foundries of aluminium, cooper, brass, etc. have also been controlled and many samples have been collected (flue dust, slag, finished products). During these controls, contaminated areas have been brought to light in two warehouses (Cs 137), in 6 companies (Cs 137 and Am 241), in two landfills of industrial waste (Cs 137) and in a quarry (Cs 137). Up to now the contaminated areas have been cleaned, except for the last one. About 150 radioactive sources on contaminated materials have been found in metal scrap. We found radioactive sources of Co 60, Ra 226, Ir 192, Kr 85, Am 241, while the contamination of metals was mainly due to Ra 226. The situation described above justifies an accurate control of the amount of scrap to reduce the risk of contamination of the workers in the working areas, in the environment and in the general public. (author)

Direct conversion of plutonium-containing materials to borosilicate glass for storage or disposal

International Nuclear Information System (INIS)

Forsberg, C.W.; Beahm, E.C.

1995-01-01

A new process, the Glass Material Oxidation and Dissolution System (GMODS), has been invented for the direct conversion of plutonium metal, scrap, and residue into borosilicate glass. The glass should be acceptable for either the long-term storage or disposition of plutonium. Conversion of plutonium from complex chemical mixtures and variable geometries into homogeneous glass (1) simplifies safeguards and security; (2) creates a stable chemical form that meets health, safety, and environmental concerns; (3) provides an easy storage form; (4) may lower storage costs; and (5) allows for future disposition options. In the GMODS process, mixtures of metals, ceramics, organics, and amorphous solids containing plutonium are fed directly into a glass melter where they are directly converted to glass. Conventional glass melters can accept materials only in oxide form; thus, it is its ability to accept materials in multiple chemical forms that makes GMODS a unique glass making process. Initial proof-of-principle experiments have converted cerium (plutonium surrogate), uranium, stainless steel, aluminum, and other materials to glass. Significant technical uncertainties remain because of the early nature of process development

Fracture detection in concrete by glass fiber cloth reinforced plastics

Science.gov (United States)

Shin, Soon-Gi; Lee, Sung-Riong

2006-04-01

Two types of carbon (carbon fiber and carbon powder) and a glass cloth were used as conductive phases and a reinforcing fiber, respectively, in polymer rods. The carbon powder was used for fabricating electrically conductive carbon powder-glass fiber reinforced plastic (CP-GFRP) rods. The carbon fiber tows and the CP-GFRP rods were adhered to mortar specimens using epoxy resin and glass fiber cloth. On bending, the electrical resistance of the carbon fiber tow attached to the mortar specimen increased greatly after crack generation, and that of the CP-GFRP rod increased after the early stages of deflection in the mortar. Therefore, the CP-GFRP rod is superior to the carbon fiber tow in detecting fractures. Also, by reinforcing with a glass fiber cloth reinforced plastic, the strength of the mortar specimens became more than twice as strong as that of the unreinforced mortar.

Development of the process for production of UO2 powder by atomization of uranyl nitrate

International Nuclear Information System (INIS)

Oliveira Lainetti, P.E. de.

1991-01-01

A method of direct conversion of uranyl nitrate hexahydrate (UNH) solution to ceramic grade uranium dioxide powders by thermal denitration in a furnace that combines atomization nozzle and a gas stirred bed is described. The main purpose of this work is to show that this alternative process is technically viable, specially if the recovery of the scrap generated in the nuclear fuel pellet production is required, without further generation of new liquid wastes. The steps for the development of the denitration unit as well as the characteristics of the final powders are described. Powder production experiments have been carried out for different atomization gas pressures and furnace upper section temperatures. Determination of impurity content, specific surface area, particle size and pore size distribution, density, U content, and O/U rate of uranium dioxide powders have been done; phase identification and morphology studies have also been performed. Sintered pellets have been studied by hydrostatic density determination and microstructure analyses. (author)

Magnesium-phosphate-glass cements with ceramic-type properties

Science.gov (United States)

Sugama, T.; Kukacka, L.E.

1982-09-23

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

Magnesium phosphate glass cements with ceramic-type properties

Science.gov (United States)

Sugama, Toshifumi; Kukacka, Lawrence E.

1984-03-13

Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

Science.gov (United States)

The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

Feasibility study of a portable smelter for scrap metals

International Nuclear Information System (INIS)

Cavendish, J.H.

1976-06-01

The use of a portable smelter to process uranium-contaminated scrap metals was studied. Objectives were to convert scrap metal located at many diverse sites into a form which would be suitable for unlicensed sale and reduce the problems associated with storing the scrap. The Foundry Design Company study indicated the portable smelter concept was feasible from an equipment and transportation standpoint. Capital costs for a 5-ton/hour (steel) nominal capacity unit were estimated to be $2,349,000. Technical evaluation indicates that all the common metals considered, i.e., iron, nickel, copper, and aluminum, are amenable to uranium decontamination by smelting except aluminum. An economic evaluation of the processing of the 30,000 tons of steel scrap to be generated by the Cascade Improvement Program by a portable smelter was made based upon information supplied by Foundry Design Company, plus the assumption that the product metal could be sold for $120.00 per ton. This evaluation indicated a net return of $2,424,000 to the government could be realized. The Health and Safety study indicated no major problems of this nature would be encountered in operating a portable smelter. The legal review indicated the proposed operation fell within the authority of existing regulations. Consideration of possible conflicts with regard to competition with the private sector was suggested

Scrap of gloveboxes No. 801-W and No. 802-W

CERN Document Server

Ohuchi, S; Kurosawa, M; Okane, S; Usui, T

2002-01-01

Both gloveboxes No. 801-W for measuring samples of uranium or plutonium and No. 802-W for analyzing the quantity of uranium or plutonium are established at twenty five years ago in the analyzing room No. 108 of Plutonium Fuel Research Facility. It was planned to scrap the gloveboxes and to establish new gloveboxes. This report describes the technical view of the scrapping works.

Characteristics of indium-tin-oxide (ITO) nanoparticle ink-coated layers recycled from ITO scraps

Science.gov (United States)

Cha, Seung-Jae; Hong, Sung-Jei; Lee, Jae Yong

2015-09-01

This study investigates the characteristics of an indium-tin-oxide (ITO) ink layer that includes nanoparticles synthesized from ITO target scraps. The particle size of the ITO nanoparticle was less than 15 nm, and the crystal structure was cubic with a (222) preferred orientation. Also, the composition ratio of In to Sn was 92.7 to 7.3 in weight. The ITO nanoparticles were well dispersed in the ink solvent to formulate a 20-wt% ITO nanoparticle ink. Furthermore, the ITO nanoparticle ink was coated onto a glass substrate, followed by heat-treatment at 600 °C. The layer showed good sheet resistances below 400 Ω/□ and optical transmittances higher than 88% at 550 nm. Thus, we can conclude that the characteristics of the layer make it highly applicable to a transparent conductive electrode.

Characterization of the calcium-fluoroaluminosilicate glass prepared by a non-hydrolytic sol-gel route for future dental application as glass ionomer cement

Directory of Open Access Journals (Sweden)

Alexandre Cestari

2009-06-01

Full Text Available Glass ionomer cements are widely employed in dentistry due to their physical, biological and mainly anti-caries properties. Glass ionomers consist of an aluminosilicate glass matrix modified with other elements, and they contain large quantities of fluorine. In this study, we report on the preparation of calcium-fluoroaluminosilicate glasses by a nonhydrolytic sol-gel route as an alternative approach to obtaining alumina-silica matrices. The glass powders were prepared via the non-hydrolytic sol-gel method, by mixing AlCl3, SiCl4, CaF2, AlF3, NaF, and AlPO4. The powders were studied by thermal analysis (TG/DTA/DSC, photoluminescence (PL, nuclear magnetic resonance (NMR27Al-29Si, and X ray diffraction (XRD. TG/DTA/DSC analyses revealed a constant mass loss due to structural changes during the heating process, which was confirmed by NMR and PL. A stable aluminosilicate matrix with potential future application as a glass ionomer base was obtained.

Preparation of High-purity Indium Oxalate Salt from Indium Scrap by Organic Acids

International Nuclear Information System (INIS)

Koo, Su-Jin; Ju, Chang-Sik

2013-01-01

Effect of organic acid on the preparation of indium-oxalate salt from indium scraps generated from ITO glass manufacturing process was studied. Effects of parameters, such as type and concentration of organic acids, pH of reactant, temperature, reaction time on indium-oxalate salt preparation were examined. The impurity removal efficiency was similar for both oxalic acid and citric acid, but citric acid did not make organic acid salt with indium. The optimum conditions were 1.5 M oxalic acid, pH 7, 80 .deg. C, and 6 hours. On the other hand, the recoveries increased with pH, but the purity decreased. The indium-oxalate salt purity prepared by two cycles was 99.995% (4N5). The indium-oxalate salt could be converted to indium oxide and indium metal by substitution reaction and calcination

Waste glass as partial mineral precursor in alkali-activated slag/fly ash system

NARCIS (Netherlands)

Zhang, S.; Keulen, A.; Arbi, K.; Ye, G.

2017-01-01

The feasibility of a waste glass powder residue (GP) from glass recycling as partial mineral precursor to produce alkali-activated materials is investigated. GP served as powder coal fly ash (PCFA) replacement within a reference system composed of 50% PCFA and 50% ground granulated blast furnace

Radioactivity in the scrap recycling process: Radiation protection aspects and experimental monitoring problems

International Nuclear Information System (INIS)

Sacco, D.; Ruggeri, F.; Bindi, G.; Bonanni, A.; Casciardi, S.; Delia, R.; Loppa, A.; Rossi, P.; Venturini, L.

1996-01-01

The steel scrap recycling by steel mill is increasing moved by profits and by purpose of protection of environmental resources. Besides the use of radioactive sources in several fields (medical, industrial and in scientific researches) on one hand, and the disposal of made radioactive materials from nuclear reactors on the other one, makes the likelihood no more negligible that some radionuclides could be found, accidental y or fraudulently, in steel recycling scrap. Radiation protection problems for surveillance both employees in the production cycle and of people and environment in general arose. First of all, we characterize different type of radioactive materials that can found in scraps, pointing out the potential hazards from exposure of workers and people and from environmental contamination, related to physical and chemical specifications of the involved radionuclides. Some suitable monitoring equipment for scrap recycling facilities are discussed, related to the different step of production cycle (transport, storage, manipulation and melting). At last experimental data, taken in some periods of the monitoring campaign made at the Italian border on imported scraps, are presented. (author)

German experience in recycling of contaminated scrap by melting

International Nuclear Information System (INIS)

Quade, U.

2003-01-01

Recycling of radioactively contaminated scrap to products for further application in the nuclear cycle is Germany as an economic alternative. It has been shown that recycling within the nuclear industry reduces the collective dose as well as the number of individuals who receive doses. In the future when decommissioning of NPP will increase, a high amount of slightly radioactive steel scrap has to be managed safely. Recycling will play an important role to keep as much of these materials within the nuclear cycle as economically possible. Siempelkamp supplies a broad range of products made of recycled material from the nuclear industry. Containers made of nodular cast iron for transport and storage of radwaste as well as containers made of concrete with iron granules additive to increase the density up to 4 g/cm 3 , are offered. Interim and final disposal volume, having consequences on costs, can be reduced when recycling is applied for slightly contaminated metallic scrap

Plutonium scrap processing at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Nixon, A.E.; McKerley, B.J.; Christensen, E.L.

1980-01-01

The Los Alamos Scientific Laboratory currently has the newest plutonium handling facility in the nation. Los Alamos has been active in the processing of plutonium almost since the discovery of this man-made element in 1941. One of the functions of the new facility is the processing of plutonium scrap generated at LASL and other sites. The feed for the scrap processing program is extremely varied, and a wide variety of contaminants are often encountered. Depending upon the scrap matrix and contaminants present, the majority of material receives a nitric acid/hydrofluoric acid or nitric acid/calcium fluoride leach. The plutonium nitrate solutions are then loaded onto an anion exchange column charged with DOWEX 1 x 4, 50 to 100 mesh, nitrate form resin. The column is eluted with 0.48 M hydroxyl amine nitrate. The Pu(NO 3 ) 3 is then precipitated as plutonium III oxalate which is calcined at 450 to 500 0 C to yield a purified PuO 2 product

Radioactive materials in scrap metal, the situation in Switzerland

International Nuclear Information System (INIS)

Jossen, H.

2005-01-01

About 10 years ago, different happenings in the Swiss and international metal scrap recycling scene created a sensibility to unwanted radioactive substances in scrap metal. Italy, one of the main buyers for scrap metals, started at its borders with systematic checks, arranged by authorities. As a consequence, in Switzerland a concept was elaborated under cooperation of the recycling companies, the Italian authorities, the Federal Office of Public Health (BAG), Swiss Federal Nuclear Safety Inspectorate (HSK) and the Swiss National Accident Insurance Fund (Suva) to fulfil the different requirements. Individual radioprotection, protection of environment, protection of work yard and machinery and the quality assurance of the recycled metals and the resulting products requires adapted solutions with the main issues: training, suitable measuring equipment and an intervention-and waste management. Detected radioactive substances are professionally recovered, stored and submitted to the radioactive waste collection. The investigation of the happenings can lead to useful hints on gaps and on chances for improvements in general radioprotection. (orig.)

Slovenian System for Protecting Against Radioactive Material in Scrap Metal Shipments

Energy Technology Data Exchange (ETDEWEB)

Stritar, A.; Cesarek, J.; Vokal Nemec, B., E-mail: andrej.stritar@gov.si [Slovenian Nuclear Safety Administration, Ljubljana (Slovenia)

2011-07-15

The Slovenian experience shows that the majority of detected orphan sources are associated with imports of scrap metal to Slovenia and transits of that material through Slovenia. Such orphan sources originate from past industrial activities and weak regulatory control in the countries of origin. In order to minimise the number of sources outside regulatory control several regulatory and law enforcement measures have been implemented. To prevent illicit trafficking across the border the 'First line of defence' - customs and police - are equipped with radiation detection devices. Since 2002, the Slovenian Nuclear Safety Administration (SNSA) has provided a 24-hour on-duty officer, who gives advice in case of the discovery of an orphan source. The majority of scrap metal collectors and re-cyclers are equipped with portal monitors and/or hand-held radiation detection equipment. Generally, good cooperation has been established between different organizations within Slovenia, with neighbouring countries and with some international organizations. To regulate the scrap metal activities, a new Decree on checking the radioactivity of shipments of metal scrap has been in force since 1 January 2008. This decree requires that every importer has to present a certificate of radiation measurement before any shipment of scrap metal is brought into Slovenia. Such measurements can be performed only by certified organizations. These organizations can obtain certification from the SNSA providing that they have the prescribed measuring devices, adequate training and procedures, and that their capabilities have been checked by a technical support organization. The experience after one year of application of the decree is positive. Awareness, including the adequacy of response, has increased. The paper discusses the general scheme for protection against illicit radioactive material in scrap metal shipments and the Slovenian experience in the last decade. (author)

Preparation of SnO_2-Glass Composite Containing Cu Particles Reduced from Copper Ions in Glass Matrix : Effect of Glass Particle Size on Microstructure and Electrical Property

OpenAIRE

Haruhisa, SHIOMI; Kaori, UMEHARA; Faculty of Engineering and Design, Kyoto Institute of Technology; Faculty of Engineering and Design, Kyoto Institute of Technology

2000-01-01

An attempt was made to improve the electrical properties of SnO_2-glass composites by dispersing Cu particles with low resistivity and positive temperature coefficient of resistance(TCR)in the glass matrix. Cu metal particles were precipitated by reducing Cu_2O previously dissolved into the matrix glass by adding LaB_6 as a reducing agent. The effect of the glass particle size, which influences the homogeneity of LaB_6 dispersion in the powder mixture before firing, on the Cu precipitation in...

BNFL Report Glass Formers Characterization

Energy Technology Data Exchange (ETDEWEB)

Schumacher, R.F.

2000-07-27

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. In addition, all of the blends may require consideration for their handling. A number of engineering considerations and recommendations were prepared based on the experimental findings, experience, and other process considerations. Recommendations for future testing are included. In conjunction with future work, it is recommended that a professional consultant be engaged to guide and assist with testing and design input.

BNFL Report Glass Formers Characterization

International Nuclear Information System (INIS)

Schumacher, R.F.

2000-01-01

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some level of solids f low problems. In addition, all of the blends may require consideration for their handling. A number of engineering considerations and recommendations were prepared based on the experimental findings, experience, and other process considerations. Recommendations for future testing are included. In conjunction with future work, it is recommended that a professional consultant be engaged to guide and assist with testing and design input

Impact on Sensex of Scrapping Double Taxation of Dividends

OpenAIRE

Ragunathan V; Varma, Jayanth R.

1997-01-01

The taxation of dividends has generated an active debate in recent months in the media. While the industry representatives have been critical of the double taxation of dividends, the Government seems to be questioning the very premise that dividends are double taxed in India. The argument that scrapping the double taxation of dividends will give the Sensex a much needed boost seems to have tilted the scales. What will be the impact of scrapping of dividend tax on Sensex? One finds that the st...

Glass transition, crystallization kinetics and pressure effect on crystallization of ZrNbCuNiBe bulk metallic glass

DEFF Research Database (Denmark)

Xing, P.F.; Zhuang, Yanxin; Wang, W.H.

2002-01-01

The glass transition behavior and crystallization kinetics of Zr48Nb8Cu14Ni12Be18 bulk metallic glass have been investigated by differential scanning calorimetry and x-ray powder diffraction (XRD). The activation energies of both glass transition and crystallization events have been obtained using...... the Kissinger method. Results indicate that this glass crystallizes by a three-stage reaction: (1) phase separation and primary crystallization of glass, (2) formation of intermetallic compounds, and (3) decomposition of intermetallic compounds and crystallization of residual amorphous phase. The pressure...

Experience during the monitoring of inactive scrap for the detection of inadvertent presence of radioactivity

International Nuclear Information System (INIS)

Sharma, Ranjit; Kumar, Anoj; Vikas; Patra, R.P.; Kumar, Vikas; Singh, Rajvir; Pradeepkumar, K.S.

2012-01-01

The inspection and certification of scrap material from nuclear facilities is a regulatory requirement to ensure that radioactive material will not reach public domain. Around the world, cases involving radioactive contamination of metallic components have occurred due to radioactive sources/contaminated metal scrap reaching the public domain. Radiological monitoring of inactive scrap material is essential as it may get into various usages in public domain where controls cannot be implemented. The method of detection is measurement of gamma dose rates due to any loose/fixed radioactive contamination in the scrap or presence of any radioactive material/source. In addition prevention of any inadvertent/malicious act leading to radioactive material reaching the public domain through scrap being essential, this monitoring gains further importance. This paper describes the methodology and experience in detection of presence of radioactivity at inactive Scrap monitoring facility. Even though radioactive sources of high strength with potential for serious environmental hazard have not been detected, few cases of contaminated material (MS plate/equipments etc with extremely low level of 137 Cs and Uranium contamination) have been detected and identified using portable gamma spectrometer. If proper monitoring is not carried out the dispersal of radioactivity to the environment can be a matter of concern due to metal scrap reaching recycling industry resulting in huge cost of decontamination and waste disposal. These events may also have negative impact on the export from the country resulting in economic losses. The impact of such events can be ruled out by effective scrap monitoring techniques which ensure that even small quantity of radioactivity escaping into public domain can be prevented. The methodology followed for monitoring of inactive scrap is found to be effective even for detection of presence of very low level of radioactivity

41 CFR 109-27.5107 - Recovery of silver from used hypo solution and scrap film.

Science.gov (United States)

2010-07-01

... used hypo solution and scrap film. 109-27.5107 Section 109-27.5107 Public Contracts and Property... § 109-27.5107 Recovery of silver from used hypo solution and scrap film. The requirements for the recovery of silver from used hypo solution and scrap film are contained in § 109-45.1003 of this chapter. ...

Evaluation of radioactive scrap metal recycling

International Nuclear Information System (INIS)

Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

1995-12-01

This report evaluates the human health risks and environmental and socio-political impacts of options for recycling radioactive scrap metal (RSM) or disposing of and replacing it. Argonne National Laboratory (ANL) is assisting the US Department of Energy (DOE), Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, in assessing the implications of RSM management alternatives. This study is intended to support the DOE contribution to a study of metal recycling being conducted by the Task Group on Recycling and Reuse of the Organization for Economic Cooperation and Development. The focus is on evaluating the justification for the practice of recycling RSM, and the case of iron and steel scrap is used as an example in assessing the impacts. To conduct the evaluation, a considerable set of data was compiled and developed. Much of this information is included in this document to provide a source book of information

Evaluation of radioactive scrap metal recycling

Energy Technology Data Exchange (ETDEWEB)

Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

1995-12-01

This report evaluates the human health risks and environmental and socio-political impacts of options for recycling radioactive scrap metal (RSM) or disposing of and replacing it. Argonne National Laboratory (ANL) is assisting the US Department of Energy (DOE), Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, in assessing the implications of RSM management alternatives. This study is intended to support the DOE contribution to a study of metal recycling being conducted by the Task Group on Recycling and Reuse of the Organization for Economic Cooperation and Development. The focus is on evaluating the justification for the practice of recycling RSM, and the case of iron and steel scrap is used as an example in assessing the impacts. To conduct the evaluation, a considerable set of data was compiled and developed. Much of this information is included in this document to provide a source book of information.

Characterization study of industrial waste glass as starting material ...

African Journals Online (AJOL)

In present study, an industrial waste glass was characterized and the potential to assess as starting material in development of bioactive materials was investigated. A waste glass collected from the two different glass industry was grounded to fine powder. The samples were characterized using X-ray fluorescence (XRF), ...

Experience during the monitoring of inactive scrap for the detection of inadvertent presence of radioactivity

International Nuclear Information System (INIS)

Sharma, Ranjit; Anoj Kumar; Vikas; Singh, Rajvir; Patra, R.P.; Vikas Kumar; Pradeepkumar, K.S.

2012-01-01

The paper describes about the experience gained during the radiation monitoring of inactive scrap generated at various nuclear facilities. This type surveillance is carried out to prevent the spread of radioactivity in public domain and also as requirement by regulatory authorities. The inspection and certification of scrap material from nuclear facilities is a regulatory requirement to ensure that no radioactive material reaches public domain. This paper describes the methodology and experience in detection of radioactivity at inactive Scrap monitoring facility. Inactive scraps (metallic and non metallic) generated from various nuclear facilities of BARC, Trombay is dispatched to Trombay Village Store (TVS) for temporary storage before auction to the public. The monitoring at the facility includes visual inspection and radiation measurement before loading the scrap in the truck. An online PC based monitoring system and portable monitoring instruments in the range (nSv/h-µSv/h) are used to carry out radiation monitoring of inactive scrap loaded in a vehicle. Radioactive source of high activity with potential for serious environmental hazard has not been detected, but few cases of presence of radioactive/contaminated material (MS plate/equipments with low level of 137 Cs contamination) have been detected and identified using portable gamma spectrometer. Implementation of strict regulatory measures and radiation monitoring at nuclear facilities can minimize the probability of radioactive material reaching the public domain. The methodology followed for monitoring of inactive scrap is found to be effective even for detection of presence of radioactivity in scrap if any. (author)

Crystallization and properties of Sr-Ba aluminosilicate glass-ceramic matrices

Science.gov (United States)

Bansal, Narottam P.; Hyatt, Mark J.; Drummond, Charles H., III

1991-01-01

Powders of roller quenched (Sr,Ba)O-Al2O3-2SiO2 glasses of various compositions were uniaxially pressed into bars and hot isostatically pressed at 1350 C for 4 hours or cold isostatically pressed and sintered at different temperatures between 800 to 1500 C for 10 or 20 hours. Densities, flexural strengths, and linear thermal expansion were measured for three compositions. The glass transition and crystallization temperatures were determined by Differential Scanning Calorimetry (DSC). The liquidus and crystallization temperature from the melt were measured using high temperature Differential Thermal Analysis (DTA). Crystalline phases formed on heat treatment of the glasses were identified by powder X ray diffraction. In Sr containing glasses, the monoclinic celsian phase always crystallized at temperatures above 1000 C. At lower temperatures, the hexagonal analog formed. The temperature for orthorhombic to hexagonal structural transformation increased monotonically with SrO content, from 327 C for BaO-Al2O3-2SiO2 to 758 C for SrO-Al2O3-2SiO2. These glass powders can be sintered to almost full densities and monoclinic celsian phase at a relatively low temperature of 1100 C.

The effect of material productivity on scrap reduction on aluminum reduction pot process

Science.gov (United States)

Huda, L. N.

2018-02-01

Scrap in the production process is defined as part of production that can not be accepted as the final product due to production failure. The amount of scarp occurring in the reduction pot production process of one of the aluminum smelting furnaces exceeds the acceptance standard of 5 to 10%. This affects the amount of production produced. The purpose of this study is to reduce the amount of scrap produced to increase the productivity of the materials used. The solution is carried-out by making improvements using Lean Six Sigma method. In the initial calculation, material productivity ranged from 0.88. Based on the study, the factors that cause the high amount of scrap produced is the use of Na2O which is inserted into the alumina is different in size and the influence of noise that occurs in pots that are difficult to control. The analysis base on Lean Six Sigma obtained process cycle efficiency (PCE) equal to 86,92% for actual condition. Process improvement is carried-out through define, measure, analyze, improve and control procedure on Na2O feeding process and PCE value decrease 6,05%. This indicates that increased process capability will reduce scrap. A decrease in scrap amount of about 6% will be able to increase material productivity by 0.05%. This indicates that continuous process control is needed to decrease the number of scraps and increase productivity.

Control and Management of Radioactive Material Inadvertently Incorporated into Scrap Metal. Proceedings of an International Conference

International Nuclear Information System (INIS)

2011-01-01

Radioactive substances can become associated with scrap metal in various ways and if not discovered they can be incorporated into steel and non-ferrous metals through the melting process. This can cause health hazards as well as environmental concerns and there can be serious commercial implications. Numerous incidents have occurred in recent years involving the discovery of radioactive substances in scrap metal and, in some cases, in metal from the melting process. These incidents have proved to be very costly in relation to the recovery and cleanup operations required but also in terms of the potential loss of confidence of the industry in scrap metal as a resource. This has led the scrap metal industry to seek ways of managing the problem. In most countries, shipments of scrap metal are monitored but at different points in the distribution chain and to different extents and efficiencies. As yet, only limited efforts towards unifying and harmonizing monitoring strategies and methods in the context of scrap metal have been made at the international level. The Conference was organized into five sessions: the global perspective, national policies and strategies, compliance with radiological criteria, management of incidents with contaminated scrap metal, and improving confidence and protecting the interests of stakeholders. The aim of the first session was to present the views and perspectives of the different organizations concerned with radioactive material in scrap metal, scrap metal recycling, steel making, radiation source security and safety and international trade and economics. The second session covered some of the national policies and strategies being used to address the control of radioactive material that has been inadvertently incorporated into scrap metal were presented. In addition to the oral presentations, contributions describing the situation in many countries of the world in the form of posters were displayed. The many posters reporting national

Control and Management of Radioactive Material Inadvertently Incorporated into Scrap Metal. Proceedings of an International Conference

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-15

Radioactive substances can become associated with scrap metal in various ways and if not discovered they can be incorporated into steel and non-ferrous metals through the melting process. This can cause health hazards as well as environmental concerns and there can be serious commercial implications. Numerous incidents have occurred in recent years involving the discovery of radioactive substances in scrap metal and, in some cases, in metal from the melting process. These incidents have proved to be very costly in relation to the recovery and cleanup operations required but also in terms of the potential loss of confidence of the industry in scrap metal as a resource. This has led the scrap metal industry to seek ways of managing the problem. In most countries, shipments of scrap metal are monitored but at different points in the distribution chain and to different extents and efficiencies. As yet, only limited efforts towards unifying and harmonizing monitoring strategies and methods in the context of scrap metal have been made at the international level. The Conference was organized into five sessions: the global perspective, national policies and strategies, compliance with radiological criteria, management of incidents with contaminated scrap metal, and improving confidence and protecting the interests of stakeholders. The aim of the first session was to present the views and perspectives of the different organizations concerned with radioactive material in scrap metal, scrap metal recycling, steel making, radiation source security and safety and international trade and economics. The second session covered some of the national policies and strategies being used to address the control of radioactive material that has been inadvertently incorporated into scrap metal were presented. In addition to the oral presentations, contributions describing the situation in many countries of the world in the form of posters were displayed. The many posters reporting national

Moisture-induced caking of beverage powders.

Science.gov (United States)

Chávez Montes, Edgar; Santamaría, Nadia Ardila; Gumy, Jean-Claude; Marchal, Philippe

2011-11-01

Beverage powders can exhibit caking during storage due to high temperature and moisture conditions, leading to consumer dissatisfaction. Caking problems can be aggravated by the presence of sensitive ingredients. The caking behaviour of cocoa beverage powders, with varying amounts of a carbohydrate sensitive ingredient, as affected by climate conditions was studied in this work. Sorption isotherms of beverage powders were determined at water activities (a(w) ) ranging from 0.1 to 0.6 in a moisture sorption analyser by gravimetry and fitted to the Brunauer-Emmett-Teller (BET) or the Guggenheim-Anderson-de Boer (GAB) equation. Glass transition temperatures (T(g) ) at several a(w) were analysed by differential scanning calorimetry and fitted to the Gordon-Taylor equation. Deduced T(g) = f(a(w) ) functions helped to identify stability or caking zones. Specific experimental methods, based on the analysis of mechanical properties of powder cakes formed under compression, were used to quantify the degree of caking. Pantry tests complemented this study to put in evidence the visual perception of powder caking with increasing a(w) . The glass transition approach was useful to predict the risks of caking but was limited to products where T(g) can be measured. On the other hand, quantification of the caking degree by analysis of mechanical properties allowed estimation of the extent of degradation for each product. This work demonstrated that increasing amounts of a carbohydrate sensitive ingredient in cocoa beverages negatively affected their storage stability. Copyright © 2011 Society of Chemical Industry.

Investigation of fatigue and mechanical properties of the pipe grade poly(vinyl chloride using recycled scraps

Directory of Open Access Journals (Sweden)

J-M. Lee

2015-04-01

Full Text Available In this paper, the effect of using pre-consumer PVC scraps on static and long-term mechanical properties is studied. The degradation characteristics of mixing virgin PVC with crushed pre-consumer and PVC pipe scraps are analyzed using various tools including Gel Permeation Chromatography (GPC, Thermogravimetric Analysis (TGA, X-ray fluorescence (XRF and Fourier Transform Infrared (FTIR spectroscopy. The variation of static mechanical properties as a function of adding pre-consumer PVC pipe scraps is investigated using the degradation analyses of recycled PVC scraps. In addition, fatigue tests are executed to evaluate the long-term durability of blending virgin PVC and recycled PVC scraps, and the fracture surface is investigated in detail to reveal the variation of the fracture mechanisms.

Scrap supply in Bosnian after war situation - sources, quality, regulation and control

International Nuclear Information System (INIS)

Pihura, Dervis

1999-01-01

Before the war, the Bosnian foundry and steel industry were supplied with scrap partly from domestic sources but mainly from foreign market. The annual steel production before the war recorded 130,000 tonnes of casting and 2,000.000 tonnes of crude steel. Most of the scrap was imported to secure and stabilize the production. During and after the war, despite a significant loss of production, efforts have been made to return to the normal production level in many ways. In the wake of the war, there has been a growing concern over the import of radioactive contaminated metallurgical scrap or low quality raw materials which are uncontrolled or of unidentified sources. In this regard, it is urgently required to establish an effective system to prevent from, to detect and to control the flow of the radioactive contaminated metallurgical scrap. The system should be established in such a way that all sorts of radioactive metallurgical elements should be controlled and prevented from use in all the metallurgical manufacturing processes, ferrous and non-ferrous alike. The coverage of control should start from the border or (air) port checkpoint where the flow of the scrap begins to the final steel product. The control system should take a form of internationally common and acceptable standards and regulations. Equipments and measurement techniques should also be internationally common. (author)

The Study on the Alteration of Simulated HLLW Glass in Aqueous Media by Inverse Gas Chromatography

International Nuclear Information System (INIS)

Zhang, Zhentao; Gan, Xueying; Yuan, Wenyi; Wang, Lei; Xing, Haiqing; Balard, Henri

2008-01-01

There exist webs of fissures inside the glass block accessible to underground water and theses fissures will influence the alteration of the glass significantly. It is very necessary to study the fissure surface properties of the glass under deep geological conditions. The alteration tests were conducted using the simulated high level radioactive glass powder immersed in Beishan (candidate disposal site) underground water with S/V ratio of 8000 m -1 at 150 deg. C and 90 deg. C for different periods. After immersion, the glass powder was filtered and dried at 120 deg. C for 3 hours. The surface properties of the dried glass powder were evaluated by inverse chromatography. The results showed that the specific surface area of the glass increases abruptly at the beginning of immersion and then increase slowly afterwards. At higher immersion temperature, the secondary phase is condensing crystals; at the lower immersion temperature, the secondary phases were loosely 'islands' with cracks or fissures. (authors)

Transboundary Movement of Radioactively Contaminated Scrap Metal - Lessons Learned

Energy Technology Data Exchange (ETDEWEB)

Nizamska, M., E-mail: m.nimzamska@bnra.bg [Emergency Planning and Preparedness Division, Bulgarian Nuclear Regulatory Agency, Sofia (Bulgaria)

2011-07-15

Starting in 1989, Bulgaria has undergone a comprehensive transformation of its economy and social conditions. Part of this process is related to the intensive privatization that started in 2001. This privatization included facilities, as well as sites that use radioactive material for different applications - industry, medicine, agriculture, science, etc. The rapid change of property ownership and, in some cases, the resulting bankruptcy, has caused difficulties in tracing and identifying radioactive sources and materials and a deterioration of the system of safety, physical protection, etc. of radioactive material. In some cases, radioactive sources were stolen because of the value of their protective containers and sold for scrap metal. This led to the occurrence of different types of radiation incidents, mainly related to the discovery of radioactive sources in scrap metal. The consequences of these incidents include the risk of radiation exposure of the workers at scrap metal yards or reprocessing facilities and of members of the public and, in addition, radioactive contamination of the environment. The Bulgarian Nuclear Regulatory Agency (BNRA) has been responding to these incidents and has carried out a series of measures to improve the control over materials (e.g. activated or surface contaminated materials) and radioactive sources and to strengthen the preventive, monitoring, emergency preparedness and mitigating measures at facility, national and transboundary levels. This paper presents an analysis of the lessons learned by the BNRA and of the control of the transboundary movement of radioactively contaminated scrap metal through the territory of Bulgaria. (author)

The melting treatment of bulk scrap from decommissioning

International Nuclear Information System (INIS)

Deng Junxian; Deng Feng

2014-01-01

Large amount of radioactive scrap will come out from reactor decommissioning. The melting treatment can be used for the volume reduction, the recycle and reuse of the radioactive scrap to reduce the mass of the radioactive waste disposal and to reuse most of the metal. The melting treatment has the advantages in volume reduction, conditioning, radionuclide confinement, reduction of radioactivity concentration, easy monitoring of radioactivity; and the effective of decontamination for several radionuclide. Therefore to use the melting technology other decontamination technology should be performed ahead, the decontamination effect of the melting should be predicted, the utility of recycle and reuse should be defined, and the secondary waste should be controlled effectively. (authors)

Lead scrap processing in rotary furnaces: a review

Energy Technology Data Exchange (ETDEWEB)

Rousseau, M

1987-01-01

Formerly, the lead scrap had been processed mainly in reverberatory and shaft furnaces or, even, in rotary furnaces (R.F.). The direct smelting of battery scrap entrains an expensive pollution control and high operating costs because of slag recirculation, coke consumption, losses in slag and matte. Nowadays, mechanized battery wrecking plants allow selective separation of casings and separators from metallic Pb (grids, poles, solders) as well as lead in non-metallic form (PbSO/sub 4/, PbO, PbO/sub 2/, contaminated with some Sb) frequently called paste. Because of their high performance and flexibility in metallurgical processing (melting, reducing, oxidizing and selective pouring) the R.F. supersedes the reverberatory furnace worldwide.

Foam Glass for Construction Materials

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund

2016-01-01

Foaming is commonly achieved by adding foaming agents such as metal oxides or metal carbonates to glass powder. At elevated temperature, the glass melt becomes viscous and the foaming agents decompose or react to form gas, causing a foamy glass melt. Subsequent cooling to room temperature, result...... in a solid foam glass. The foam glass industry employs a range of different melt precursors and foaming agents. Recycle glass is key melt precursors. Many parameters influence the foaming process and optimising the foaming conditions is very time consuming. The most challenging and attractive goal is to make...... low density foam glass for thermal insulation applications. In this thesis, it is argued that the use of metal carbonates as foaming agents is not suitable for low density foam glass. A reaction mechanism is proposed to justify this result. Furthermore, an in situ method is developed to optimise...

A Pilot Assessment of Occupational Health Hazards in the US Electronic Scrap Recycling Industry.

Science.gov (United States)

Ceballos, Diana M; Gong, Wei; Page, Elena

2015-01-01

The National Institute for Occupational Safety and Health (NIOSH) surveyed a randomly selected sample of electronic scrap (e-scrap) recycling facilities nationwide to characterize work processes, exposures, and controls. Despite multiple attempts to contact 278 facilities, only 47 responded (17% response rate). Surveyed facilities reported recycling a wide variety of electronics. The most common recycling processes were manual dismantling and sorting. Other processes included shredding, crushing, and automated separation. Many facilities reported that they had health and safety programs in place. However, some facilities reported the use of compressed air for cleaning, a practice that can lead to increased employee dust exposures, and some facilities allowed food and drinks in the production areas, a practice that can lead to ingestion of contaminants. Although our results may not be generalizable to all US e-scrap recycling facilities, they are informative regarding health and safety programs in the industry. We concluded that e-scrap recycling has the potential for a wide variety of occupational exposures particularly because of the frequent use of manual processes. On-site evaluations of e-scrap recyclers are needed to determine if reported work processes, practices, and controls are effective and meet current standards and guidelines. Educating the e-scrap recycling industry about health and safety best practices, specifically related to safe handling of metal dust, would help protect employees.

Radiation effects in glass waste forms for high-level waste and plutonium disposal

International Nuclear Information System (INIS)

Weber, W.J.; Ewing, R.C.

1997-01-01

A key challenge in the permanent disposal of high-level waste (HLW), plutonium residues/scraps, and excess weapons plutonium in glass waste forms is the development of predictive models of long-term performance that are based on a sound scientific understanding of relevant phenomena. Radiation effects from β-decay and α-decay can impact the performance of glasses for HLW and Pu disposition through the interactions of the α-particles, β-particles, recoil nuclei, and γ-rays with the atoms in the glass. Recently, a scientific panel convened under the auspices of the DOE Council on Materials Science to assess the current state of understanding, identify important scientific issues, and recommend directions for research in the area of radiation effects in glasses for HLW and Pu disposition. The overall finding of the panel was that there is a critical lack of systematic understanding on radiation effects in glasses at the atomic, microscopic, and macroscopic levels. The current state of understanding on radiation effects in glass waste forms and critical scientific issues are presented

Abrasive wear of enamel by bioactive glass-based toothpastes.

Science.gov (United States)

Mahmood, Asad; Mneimne, Mohammed; Zou, Li Fong; Hill, Robert G; Gillam, David G

2014-10-01

To determine the abrasivity of a 45S5 bioactive glass based toothpaste on enamel as a function of the particle size and shape of the glass. 45S5 glass was synthesized ground and sieved to give various particle sized fractions toothpastes and their tooth brush abrasivity measured according to BS EN ISO11609 methodology. Enamel loss increased with increasing particle size. The percussion milled powder exhibited particles that had sharp edges and the pastes were significantly more abrasive than the pastes made with round ball milled powders. One interesting observation made during the present study was that there was preferential wear of the enamel at the dentin-enamel junction (DEJ), particularly with the coarse particle sized pastes.

A model for recovery of scrap monolithic uranium molybdenum fuel by electrorefining

Science.gov (United States)

Van Kleeck, Melissa A.

The goal of the Reduced Enrichment for Research and Test Reactors program (RERTR) is toreduce enrichment at research and test reactors, thereby decreasing proliferation risk at these facilities. A new fuel to accomplish this goal is being manufactured experimentally at the Y12 National Security Complex. This new fuel will require its own waste management procedure,namely for the recovery of scrap from its manufacture. The new fuel is a monolithic uraniummolybdenum alloy clad in zirconium. Feasibility tests were conducted in the Planar Electrode Electrorefiner using scrap U-8Mo fuel alloy. These tests proved that a uranium product could be recovered free of molybdenum from this scrap fuel by electrorefining. Tests were also conducted using U-10Mo Zr clad fuel, which confirmed that product could be recovered from a clad version of this scrap fuel at an engineering scale, though analytical results are pending for the behavior of Zr in the electrorefiner. A model was constructed for the simulation of electrorefining the scrap material produced in the manufacture of this fuel. The model was implemented on two platforms, Microsoft Excel and MatLab. Correlations, used in the model, were developed experimentally, describing area specific resistance behavior at each electrode. Experiments validating the model were conducted using scrap of U-10Mo Zr clad fuel in the Planar Electrode Electrorefiner. The results of model simulations on both platforms were compared to experimental results for the same fuel, salt and electrorefiner compositions and dimensions for two trials. In general, the model demonstrated behavior similar to experimental data but additional refinements are needed to improve its accuracy. These refinements consist of a function for surface area at anode and cathode based on charge passed. Several approximations were made in the model concerning areas of electrodes which should be replaced by a more accurate function describing these areas.

Photovoltaic Properties of Co-doped ZnO Thin Film on Glass Substrate

International Nuclear Information System (INIS)

Sabia Aye; Zin Ma Ma; May Nwe Oo; Than Than Win; Yin Maung Maung; Ko Ko Kyaw Soe

2011-12-01

Cobalt (Co) 0.4 mol doped zinc oxide (ZnO) fine powder was prepared by solid state mixed oxide route. Phase formation and crystal structure of Co-doped ZnO (CZO) powder were examined by X-ray diffraction (XRD). Scanning Electron Microscopy (SEM) was used to observe the micro structure of Co doped ZnO powder. Energy Dispersive X-ray Fluorescent (EDXRF) technique gave the elemental content of cobalt and zinc. Co-doped ZnO film was formed on glass substrate by spin coating technique. Photovoltaic properties of CZO/glass cell were measured.

US Department of Energy`s weapons complex scrap metal inventory. Research report

Energy Technology Data Exchange (ETDEWEB)

Duda, J.R.

1993-07-01

Two tasks comprise the thrust of this contracted effort. Task 1 is the development of a Source List and is based on determining a list of public documents pertaining to contaminated/uncontaminated scrap metals, equipment, and other materials of value, were they not contaminated or could they be decontaminated. Task 2 is to develop an inventory of such materials from the Task 1 list of public documentation. In more detail, the Task 2 Inventory Report is based upon fulfillment of the following requirement to prepare and submit an Inventory Report based on the information obtained in the Source List. The Inventory Report shall define the type, quantity, and location of used equipment, scrap metal, and other materials existing within DOE`s system. The Inventory Report shall list: the site where the equipment, scrap metal, or other material resides; the type and size of equipment; the type and volume and/or weight of scrap metal or other material; its source; the type and level of contamination; its accessibility; the current annual rate of generation; and the projected annual rate of generation of the material.

Foaming of CRT panel glass powder using Na2CO3

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup

2014-01-01

The recycling of glass from obsolete cathode ray tubes (CRT) has hitherto only occurred to a very limited extent, but the production of foam glass used as an insulation material component has recently been proposed as a promising recycling method. CRT panel glass has high recycling potential due...... to its non-hazardous composition. Here we report on the foaming of CRT panel glass using Na2CO3 as the foaming agent. We explore how heat treatment temperature and concentration of Na2CO3 affect the density and porosity of the foam glasses, and whether Na2O is incorporated in the glass network....... The optimum foaming temperature for minimising density and maximising closed porosity is found to be between 1023 and 1123 K. The pore structure depends on the amount of added Na2CO3, viz, the pores generally become more open with increasing Na2CO3 content. A minimum density of 0·28 g/cm3 is found when 14 wt...

Effect of B2O3 and P2O5 on fluorosilicic mica glass-ceramic sintering process

Directory of Open Access Journals (Sweden)

Wu S.

2010-01-01

Full Text Available To study the effect of B2O3 and P2O5 on fluorosilicic mica glass-ceramic sintering process, six sets of K2O-MgO-SiO2-F glasses were prepared by using B2O3 and P2O5 as sintering aid, respectively. Green bodies of the glass powder were formed by gel casting and sintered at 800, 850, 900, 950, 1000oC for 6 hours, resectively. The sintering and crystallization behavior were studied by thermal shrinkage , X-ray diffraction and SEM. The results showed that the shrinkage rate of the glass with 2wt% B2O3 and P2O5 was highest, while the rate of the glass with 5wt% P2O5 was lowest. An additional crystal other than fluorosilicic mica was precipitated in the glass ceramics generated by sintering of glass powder. The present results confirmed that the glass powder of pure K2O-MgO-SiO2-Fsystem had poor sinterability, while glass powder with minor addition of P2O5 and/or B2O3 showed good sinterability. This result was also verified by SEM.

Kekuatan perlekatan geser semen ionomer kaca terhadap dentin dan NiCr alloy (Shear bond strenght of glass ionomer cement in dentin and NiCr alloy

Directory of Open Access Journals (Sweden)

Mira Leonita

2006-03-01

Full Text Available Glass ionomer cements were used broadly in restorative dentistry. That’s why researchers always try to invent new form of glass ionomer cement. The newest invention was the paste-paste formulation. Shear bond strenght of powder-liquid glass ionomer cement and paste-paste glass ionomer cement in dentin and NiCr alloy was tested to 4 groups of samples. Each group consisted contain 6 samples that were shaped into cylinder with 4 mm of diameter and 5 mm of height. Group A was dentin with powder-liquid glass ionomer cement, group B was dentin with paste-paste glass ionomer cement, group C was alloy with powder-liquid glass ionomer cement, and group D was alloy with paste-paste glass ionomer cement. Each sample in each group was tested with Autograph. The datas were analyzed statistically using T-test with level of signficance 0.05. The result showed that powder-liquid glass ionomer cement shear bond strenght was 211 N and paste-paste glass ionomer cement was 166.92 N. That showed that powder-liquid glass ionomer cement had a better shear bond strenght.

Characterization of Irradiated and Non-Irradiated Rubber from Automotive Scrap Tires

Science.gov (United States)

Souza, Clécia Moura; Silva, Leonardo G.

The aim of this work was to characterize the samples of irradiated and non-irradiated rubber from automotive scrap tires. Rubber samples from scrap tires were irradiated at irradiation doses of 200, 400 and 600kGy in an electron beam accelerator. Subsequently, both the irradiated and non-irradiated samples were characterized by thermogravimetry (TG), differential scanning calorimetry (DSC), tensile strength mechanical test, and Fourier transform infrared (FTIR) spectrophotometry.

The Research of Scrapped Automobiles Recycling and Disassembling Industry Development Based on Auto Industry Chain

Directory of Open Access Journals (Sweden)

linhua Pang

2015-01-01

Full Text Available The number of China’s scrapped car is on an explosively growing trend, and the development of scrapped car recycling industry has a golden prospect. The current scrapped car recycling system is not perfect in our country, because related industries driven by market develop slowly, and there are some outstanding problems such as potential safety risks, environmental pollution and resource waste. The paper analyzes and studies the existing problems and countermeasures to investigate the development strategy of scrapped car recycling industry according to the whole automobile industry chain construction, technology and equipment conditions, policy guidance, etc. and at last explore the new industrial development pattern of serving automobile reverse design.

Characterization of naturally occurring radioactive materials and Cobald-60 contaminated ferrous scraps from steel industries

International Nuclear Information System (INIS)

Chao, H.E.; Chiu, H.S.; Hunga, J.Y.; His, H.W.; Chen, Y.B.

2002-01-01

Since the occurrence of radioactively contaminated rebar incident in 1992, steel industries in Taiwan were encouraged by Atomic Energy Council (AEC) to install portal monitor to detect the abnormal radiation in shipments of metal scrap feed. From 1994 through 1999, there were 53 discoveries of radioactivity in ferrous scraps by steel companies. These include 15 orphan radioactive sources, 16 cobalt-60 contaminated rebars, 20 Naturally Occurring Radioactive Material (NORM) contaminated scraps, and two unknowns. Most NORM-contaminated scraps were from abroad. The NORM and cobalt-60 contaminated scraps were taken from the steel mills and analyzed in laboratory. The analytical results of scales and sludge sampled from NORM-contaminated scraps combining with the circumstantial evidences indicate that five possible industrial processes may be involved. They are oil production and treatment, heavy mineral sand benefication and rare earth processing, copper mining and processing, recovery of ammonium chloride by lime adsorption in Ammonium-soda process, and tailing of uranium enrichment process. The cobalt-60 activity and trace elements concentrations of contaminated rebars confirm that all of them were produced domestically in the period from Oct. 1982 to Jan. 1983, when the cobalt-60 sources were lost and entered the electric arc furnace to produce the contaminated rebars. (author)

Health risk and impact evaluation for recycling of radioactive scrap metal

International Nuclear Information System (INIS)

Nieves, L.A.; Chen, S.Y.; Murphie, W.E.; Lilly, M.J. III

1994-01-01

The DoE, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development in providing analytical support for developing international standards for recycling of radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing health, environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of international inventory estimates for contaminated metals; investigation of international scrap metal markets; assessment of radiological and non-radiological human health risks; impacts on environmental quality and resources; and investigation of social and political factors. The RSM disposal option is being assessed with regard to the environmental and health impacts of replacing the metals if they are withdrawn from use. Impact estimates are developed for steel as an illustrative example because steel comprises a major portion of the scrap metal inventory. Current and potential sources of RSM include nuclear power plants, fuel cycle and weapons production facilities, industrial and medical facilities and equipment, and petroleum and phosphate rock extraction equipment. Millions of metric tons (t) of scrap iron and steel, stainless steel, and copper, as well as lesser quantities of aluminum, nickel, lead, and zirconium, are likely to become available in the future as these facilities are withdrawn from service

The Influence of Home Scrap on Mechanical Properties of MgAl9Zn1 Alloy Castings

Directory of Open Access Journals (Sweden)

Konopka Z.

2017-06-01

Full Text Available The work presents the results of examinations concerning the influence of various amounts of home scrap additions on the properties of castings made of MgAl9Zn1 alloy. The fraction of home scrap in the metal charge ranged from 0 to 100%. Castings were pressure cast by means of the hot-chamber pressure die casting machine under the industrial conditions in one of the domestic foundries. The examinations consisted in the determination of the following properties: tensile strength Rm, yield strength Rp0.2, and the unit elongation A5, all being measured during the static tensile test. Also, the hardness measurements were taken by the Brinell method. It was found that the mechanical properties (mainly the strength properties are being improved up to the home scrap fraction of 50%. Their values were increased by about 30% over this range. Further rise in the home scrap content, however, brought a definite decrease in these properties. The unit elongation A5 exhibited continual decrease with an increase in the home scrap fraction in the metal charge. A large growth of hardness was noticed for the home scrap fraction increasing up to the value of 50%. Further increasing the home scrap percentage, however, did not result in a significant rise of the hardness value any more.

Low temperature sintering of fluorapatite glass-ceramics

Science.gov (United States)

Denry, Isabelle; Holloway, Julie A.

2014-01-01

Fluorapatite glass-ceramics have been shown to be excellent candidates as scaffold materials for bone grafts, however, scaffold production by sintering is hindered by concurrent crystallization of the glass. Our goal was to investigate the effect of Ca/Al ratio on the sintering behavior of Nb-doped fluorapatite-based glasses in the SiO2-Al2O3-P2O5-MgO-Na2O-K2O-CaO-CaF2 system. Glass compositions with Ca/Al ratio of 1 (A), 2 (B), 4 (C) and 19 (D) were prepared by twice melting at 1525°C for 3h. Glasses were either cast as cylindrical ingots or ground into powders. Disc-shaped specimens were prepared by either sectioning from the ingots or powder-compacting in a mold, followed by heat treatment at temperatures ranging between 700 and 1050°C for 1h. The density was measured on both sintered specimens and heat treated discs as controls. The degree of sintering was determined from these measurements. XRD showed that fluorapatite crystallized in all glass-ceramics. A high degree of sintering was achieved at 775°C for glass-ceramic D (98.99±0.04%), and 900°C for glass-ceramic C (91.31±0.10). Glass-ceramics A or B were only partially sintered at 1000°C (63.6±0.8% and 74.1±1.5%, respectively). SEM revealed a unique microstructure of micron-sized spherulitic fluorapatite crystals in glass-ceramics C and D. Increasing the Ca/Al ratio promoted low temperature sintering of fluorapatite glass-ceramics, which are traditionally difficult to sinter. PMID:24252652

Electroless silver coating of rod-like glass particles.

Science.gov (United States)

Moon, Jee Hyun; Kim, Kyung Hwan; Choi, Hyung Wook; Lee, Sang Wha; Park, Sang Joon

2008-09-01

An electroless silver coating of rod-like glass particles was performed and silver glass composite powders were prepared to impart electrical conductivity to these non-conducting glass particles. The low density Ag-coated glass particles may be utilized for manufacturing conducting inorganic materials for electromagnetic interference (EMI) shielding applications and the techniques for controlling the uniform thickness of silver coating can be employed in preparation of biosensor materials. For the surface pretreatment, Sn sensitization was performed and the coating powders were characterized by scanning electron microscopy (SEM), focused ion beam microscopy (FIB), and atomic force microscopy (AFM) along with the surface resistant measurements. In particular, the use of FIB technique for determining directly the Ag-coating thickness was very effective on obtaining the optimum conditions for coating. The surface sensitization and initial silver loading for electroless silver coating could be found and the uniform and smooth silver-coated layer with thickness of 46 nm was prepared at 2 mol/l of Sn and 20% silver loading.

Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis.

Science.gov (United States)

Uzun, B B; Yaman, E

2014-10-01

The degradation kinetics of Juglans regia shell, scrap tyre and their blends were investigated using a thermogravimetric analysis method. Experiments were performed under dynamic conditions and a nitrogen atmosphere in the range 293 to 973 K at different heating rates. During pyrolysis of J. regia shell three mass loss zones were specified as removal of water, decomposition of hemicelluloses and cellulose, and decomposition of lignin. The degradation curves of scrap tyre showed merely one stage which was due to decomposition of styrene butadiene rubber. The kinetic parameters were calculated using both Arrhenius and Coats-Redfern methods. By adopting the Arrhenius method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blends were found to be 69.22, 71.48 and 47.03 kJ mol(-1), respectively. Additionally, by using the Coats-Redfern method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blend were determined as 99.85, 78.72 and 63.81 kJ mol(-1), respectively. The addition of J. regia shell to scrap tyre caused a reduction in the activation energies. The difference of weight loss was measured to examine interactions between raw materials. The maximum difference between experimental and theoretical mass loss was 5% at about 648 K with a heating rate of 20 K min(-1). These results indicated a significant synergistic effect was available during co-pyrolysis of J. regia shell and scrap tyre in the high temperature region. © The Author(s) 2014.

Assessment of recycling or disposal alternatives for radioactive scrap metal

International Nuclear Information System (INIS)

Murphie, W.E.; Lilly, M.J. III; Nieves, L.A.; Chen, S.Y.

1993-01-01

The US Department of Energy, Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, is participating with the Organization for Economic Cooperation and Development in providing analytical support for evaluation of management alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives. This effort includes development of inventory estimates for contaminated metals; investigation of scrap metal market structure, processes, and trends; assessment of radiological and nonradiological effects of recycling; and investigation of social and political factors that are likely to either facilitate or constrain recycling opportunities. In addition, the option of scrap metal disposal is being assessed, especially with regard to the environmental and health impacts of replacing these metals if they are withdrawn from use. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A open-quotes tieredclose quotes concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conservatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested

Pressure effect of glass transition temperature in Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk metallic glass

DEFF Research Database (Denmark)

Jiang, Jianzhong; Roseker, W.; Sikorski, M.

2004-01-01

Pressure effects on glass transition temperature and supercooled liquid region of a Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass have been investigated by performing in situ high-temperature and high-pressure x-ray powder diffraction measurements using synchrotron radiation. The glass transition was det...... range of 0-2.2 GPa. This method opens a possibility to study the pressure effect of glass transition process in glassy systems under high pressures (>1 GPa). (C) 2004 American Institute of Physics.......Pressure effects on glass transition temperature and supercooled liquid region of a Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass have been investigated by performing in situ high-temperature and high-pressure x-ray powder diffraction measurements using synchrotron radiation. The glass transition...... was detected from the change of the slope of peak position as a function of temperature. It is found that the glass transition temperature increases with pressure by 4.4 K/GPa for the Zr46.8Ti8.2Cu7.5Ni10Be27.5 bulk glass, and the supercooled liquid range decreases with pressure by 2.9 K/GPa in a pressure...

Fully automated laboratory for the assay of plutonium in wastes and recoverable scraps

International Nuclear Information System (INIS)

Guiberteau, P.; Michaut, F.; Bergey, C.; Debruyne, T.

1990-01-01

To determine the plutonium content of wastes and recoverable scraps in intermediate size containers (ten liters) an automated laboratory has been carried out. Two passive methods of measurement are used. Gamma ray spectrometry allows plutonium isotopic analysis, americium determination and plutonium assay in wastes and poor scraps. Calorimetry is used for accurate (± 3%) plutonium determination in rich scraps. A full automation was realized with a barcode management and a supply robot to feed the eight assay set-ups. The laboratory works on a 24 hours per day and 365 days per year basis and has a capacity of 8,000 assays per year

New life of recycled rare earth-oxides powders for lighting applications.

Science.gov (United States)

Carlo Ricci, Pier; Murgia, Massimiliano; Carbonaro, Carlo Maria; Sgariotto, Serena; Stagi, Luigi; Corpino, Riccardo; Chiriu, Daniele; Grilli, Maria Luisa

2018-03-01

In this work we analysed the optical and structural properties of Ce:YAG regenerated phosphors. The concentrate resulted as the final product of an industrial recycling process of waste electrical and electronic equipment (WEEE), and in particular fluorescent powders coming from spent lamps treatment plant. The waste pristine materials were re-utilized without any further purification and or separation process as starting materials to obtain a YAG matrix (Y2Al5O12) doped with Cerium ions. We tested out the recovered concentrate against commercial Ce:YAG phosphors comparing their structural and optical properties by means of XRD measurements and steady time and time resolved luminescence. The analysis reveals that the new phosphors obtained by scrap powder have the same crystal structure as the commercial reference sample and comparable optical properties. In particular, the Ce-related emission efficiency has a quantum yield of about 0.75 when excited at 450 nm, in good agreement with our reference sample and with the one of commercial powder presently exploited in white LED. This achievement strongly suggests the possibility of a new life for the exhausted phosphors and a possible step forward to a complete circular process for lighting equipment.

Recovery of plutonium from insulation, scrap glass, and sand-slag residues

International Nuclear Information System (INIS)

Ziegler, D.L.; Garnett, J.E.; Fraser, J.K.

1979-01-01

Laboratory experiments were performed to evaluate methods for removing plutonium from insulation, glass leach heel, and sand and slag heel. The methods evaluated included hydrochloric acid leaching, nitric acid leaching, and a treatment consisting of a fusion step followed by acid leaching. Results indicate that a nitric acid leach is effective in lowering the plutonium concentration of these solid wastes to the desired limit, if multiple contacts are used. A hydrochloric acid leach was found to be superior to a nitric acid leach for removing plutonium from the residues

Advanced technologies for decontamination and conversion of scrap metal

International Nuclear Information System (INIS)

Muth, T.R.; Shasteen, K.E.; Liby, A.L.

1995-01-01

The Department of Energy (DOE) accumulated large quantities of radioactive scrap metal (RSM) through historic maintenance activities. The Decontamination and Decommissioning (D ampersand D) of major sites formerly engaged in production of nuclear materials and manufacture of nuclear weapons will generate additional quantities of RSM, as much as 3 million tons of such metal according to a recent study. The recycling of RSM is quickly becoming appreciated as a key strategy in DOE's cleanup of contaminated sites and facilities. The work described here has focused on recycle of the concentrated and high-value contaminated scrap metal resource that will arise from cleanup of DOE's gaseous diffusion plants

Advanced technologies for decontamination and conversion of scrap metal

Energy Technology Data Exchange (ETDEWEB)

Muth, T.R.; Shasteen, K.E.; Liby, A.L. [Manufacturing Sciences Corp., Oak Ridge, TN (United States)] [and others

1995-10-01

The Department of Energy (DOE) accumulated large quantities of radioactive scrap metal (RSM) through historic maintenance activities. The Decontamination and Decommissioning (D&D) of major sites formerly engaged in production of nuclear materials and manufacture of nuclear weapons will generate additional quantities of RSM, as much as 3 million tons of such metal according to a recent study. The recycling of RSM is quickly becoming appreciated as a key strategy in DOE`s cleanup of contaminated sites and facilities. The work described here has focused on recycle of the concentrated and high-value contaminated scrap metal resource that will arise from cleanup of DOE`s gaseous diffusion plants.

Hydrogen isotope storage in zircaloy scrap

Energy Technology Data Exchange (ETDEWEB)

Lee, H. S.; Kuk, I. H.; Chung, H.; Paek, S. W.; Kang, H. S

1999-08-01

8 MCi of tritium a year will be produced after wolsong TRF is in operation. The metal hydride form is one of useful tritium storage. The metals in use for metal hydride are uranium, titanium, etc., however uranium is limited to use by regulation, and titanium is relatively costly. Both metals are not produced in country but whole amount is imported. On the other hand 2,000kg of zircaloy scrap is produced by CANDU nuclear fuel fabrication process, which is also useful for hydrogen storage. The purpose of this study is to evaluation of hydrogen absorption capacity for zircaloy scrap that is produced as waste by CANDU nuclear fuel fabrication process. The sample evacuated for an hour at 1000 deg C. The strip showed higher capacity : 0.7 at 25 deg C, 2.0 at 200 deg C, 2.0 at 200 deg C, 2.0 at 400 deg C, respectively. The H/M values for commercial zircaloy sponge were 2.0 at 25 deg C and 2.0 at 400 deg C.

Hydrogen isotope storage in zircaloy scrap

International Nuclear Information System (INIS)

Lee, H. S.; Kuk, I. H.; Chung, H.; Paek, S. W.; Kang, H. S.

1999-08-01

8 MCi of tritium a year will be produced after wolsong TRF is in operation. The metal hydride form is one of useful tritium storage. The metals in use for metal hydride are uranium, titanium, etc., however uranium is limited to use by regulation, and titanium is relatively costly. Both metals are not produced in country but whole amount is imported. On the other hand 2,000kg of zircaloy scrap is produced by CANDU nuclear fuel fabrication process, which is also useful for hydrogen storage. The purpose of this study is to evaluation of hydrogen absorption capacity for zircaloy scrap that is produced as waste by CANDU nuclear fuel fabrication process. The sample evacuated for an hour at 1000 deg C. The strip showed higher capacity : 0.7 at 25 deg C, 2.0 at 200 deg C, 2.0 at 200 deg C, 2.0 at 400 deg C, respectively. The H/M values for commercial zircaloy sponge were 2.0 at 25 deg C and 2.0 at 400 deg C

Remelting of Aluminium by Continuous Submersion of Rolled Scrap

Energy Technology Data Exchange (ETDEWEB)

Farner, Snorre

2000-12-01

When remelting aluminium scrap, metal losses due to dross generation is a common problem. Reduction of these losses will give substantial economic and environmental benefits. Dross is generated when aluminium metal oxidizes and films of oxide envelope molten metal. When a cold metal object is immersed in a melt, the heat of the melt around this is transferred so rapidly into the object that a shell of melt often solidifies to the surface of the object. When scrap with low bulk density is charged to a melt, solidification of melt on the cold scrap prevents melt from entering the cavities in the bulk of the scrap, and the bulk density remains low. Thus the scrap tends to float on the melt surface. Submersion of this scrap is important to avoid oxidation and subsequent dross generation. One solution to this is to roll scrap to a strip and feed it into the melt. This system has been examined by studying feeding of a continuous, thin aluminium plate into molten aluminium. Also, the effect of lacquer was considered, as well as feeding the plate into a launder with melt flowing along the surface of the plate. An analytical, one-dimensional, steady-state model has been developed to describe the melting and the melting mechanisms. It is based on a shell solidifying on the plate surface and a gap introducing a thermal resistance 1/h{sub g} between the shell and the plate. The thermal resistance 1/h{sub l} of the boundary layer of the melt is included. Depending on these resistances, the initial temperature of the plate and the melt temperature, a shell will form, and the plate will penetrate a distance P into the melt before it melts away. An experimental apparatus was designed and constructed to feed aluminium plate from a coil into a melt bath at a specified velocity. The plate could be withdrawn rapidly to ''freeze'' the situation like it was below the melt surface. The penetration depth P of the plate could be measured and shell formation observed

Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

Science.gov (United States)

Sreekumar, K. P.; Saxena, S. K.; Kumar, Yogendra; Thiyagarajan, T. K.; Dash, Ashutosh; Ananthapadmanabhan, P. V.; Venkatesh, Meera

2010-02-01

Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700°C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Sreekumar, K P; Saxena, S K; Kumar, Yogendra; Thiyagarajan, T K; Dash, Ashutosh; Ananthapadmanabhan, P V; Venkatesh, Meera, E-mail: nair.sreekumar@gmail.co [Laser and Plasma Technology Division, Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

2010-02-01

Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700{sup 0}C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

Studies on the preparation and plasma spherodization of yttrium aluminosilicate glass microspheres for their potential application in liver brachytherapy

International Nuclear Information System (INIS)

Sreekumar, K P; Saxena, S K; Kumar, Yogendra; Thiyagarajan, T K; Dash, Ashutosh; Ananthapadmanabhan, P V; Venkatesh, Meera

2010-01-01

Plasma spheroidization exploits the high temperature and high enthalpy available in the thermal plasma jet to melt irregularly shaped powder particles and quench them to get dense spherical particles. Plasma spheroidization is a versatile process and can be applied to metals, ceramics, alloys and composites to obtain fine spherical powders. Radioactive microspheres incorporated with high energetic beta emitting radioisotopes have been reported to be useful in the palliative treatment of liver cancer. These powders are to be prepared in closer range of near spherical morphology in the size range 20-35 microns. Inactive glass samples were prepared by heating the pre-calculated amount of glass forming ingredients in a recrystallized alumina crucible. The glass was formed by keeping the glass forming ingredients at 1700 0 C for a period of three hours to form a homogeneous melt. After cooling, the glass was recovered from the crucible by crushing and was subsequently powdered mechanically with the help of mortar and pestle. This powder was used as the feed stock for plasma spheroidization using an indigenously developed 40 kW plasma spray system. Experiments were carried out at various operating parameters. The operating parameters were optimised to get spheroidised particles. The powder was sieved to get the required size range before irradiation.

Economic and policy instrument analyses in support of the scrap tire recycling program in Taiwan.

Science.gov (United States)

Chang, Ni-Bin

2008-02-01

Understanding the cost-effectiveness and the role of economic and policy instruments, such as the combined product tax-recycling subsidy scheme or a tradable permit, for scrap tire recycling has been of crucial importance in a market-oriented environmental management system. Promoting product (tire) stewardship on one hand and improving incentive-based recycling policy on the other hand requires a comprehensive analysis of the interfaces and interactions in the nexus of economic impacts, environmental management, environmental valuation, and cost-benefit analysis. This paper presents an assessment of the interfaces and interactions between the implementation of policy instruments and its associated economic evaluation for sustaining a scrap tire recycling program in Taiwan during the era of the strong economic growth of the late 1990s. It begins with an introduction of the management of the co-evolution between technology metrics of scrap tire recycling and organizational changes for meeting the managerial goals island-wide during the 1990s. The database collected and used for such analysis covers 17 major tire recycling firms and 10 major tire manufacturers at that time. With estimates of scrap tire generation and possible scale of subsidy with respect to differing tire recycling technologies applied, economic analysis eventually leads to identify the associated levels of product tax with respect to various sizes of new tires. It particularly demonstrates a broad perspective of how an integrated econometric and engineering economic analysis can be conducted to assist in implementing policy instruments for scrap tire management. Research findings indicate that different subsidy settings for collection, processing, and end use of scrap tires should be configured to ameliorate the overall managerial effectiveness. Removing the existing boundaries between designated service districts could strengthen the competitiveness of scrap tires recycling industry, helping to

Foaming Glass Using High Pressure Sintering

DEFF Research Database (Denmark)

Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

Foam glass is a high added value product which contributes to waste recycling and energy efficiency through heat insulation. The foaming can be initiated by a chemical or physical process. Chemical foaming with aid of a foaming agent is the dominant industrial process. Physical foaming has two...... to expand. After heat-treatment foam glass can be obtained with porosities of 80–90 %. In this study we conduct physical foaming of cathode ray tube (CRT) panel glass by sintering under high pressure (5-25 MPa) using helium, nitrogen, or argon at 640 °C (~108 Pa s). Reheating a sample in a heating...... variations. One way is by saturation of glass melts with gas. The other involves sintering of powdered glass under a high gas pressure resulting in glass pellets with high pressure bubbles entrapped. Reheating the glass pellets above the glass transition temperature under ambient pressure allows the bubbles...

Low temperature sintering of fluorapatite glass-ceramics.

Science.gov (United States)

Denry, Isabelle; Holloway, Julie A

2014-02-01

Fluorapatite glass-ceramics have been shown to be excellent candidates as scaffold materials for bone grafts, however, scaffold production by sintering is hindered by concurrent crystallization of the glass. Objective, our goal was to investigate the effect of Ca/Al ratio on the sintering behavior of Nb-doped fluorapatite-based glasses in the SiO2-Al2O3-P2O5-MgO-Na2O-K2O-CaO-CaF2 system. Methods, glass compositions with Ca/Al ratio of 1 (A), 2 (B), 4 (C) and 19 (D) were prepared by twice melting at 1525°C for 3h. Glasses were either cast as cylindrical ingots or ground into powders. Disk-shaped specimens were prepared by either sectioning from the ingots or powder-compacting in a mold, followed by heat treatment at temperatures ranging between 700 and 1050°C for 1h. The density was measured on both sintered specimens and heat treated discs as controls. The degree of sintering was determined from these measurements. Results and Significance XRD showed that fluorapatite crystallized in all glass-ceramics. A high degree of sintering was achieved at 775°C for glass-ceramic D (98.99±0.04%), and 900°C for glass-ceramic C (91.31±0.10). Glass-ceramics A or B were only partially sintered at 1000°C (63.6±0.8% and 74.1±1.5%, respectively). SEM revealed a unique microstructure of micron-sized spherulitic fluorapatite crystals in glass-ceramics C and D. Increasing the Ca/Al ratio promoted low temperature sintering of fluorapatite glass-ceramics, which are traditionally difficult to sinter. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Hydrogen-induced high damping of bulk metallic glasses

International Nuclear Information System (INIS)

Hasegawa, M.

2009-01-01

There are two important topics concerned with the recent researches on the damping materials of hydrogenated metallic glasses (HMGs). One is the mechanism of the high hydrogen-induced internal friction of HMGs. The other is the materials processing of 'bulk' HMGs for engineering. This article describes the summary of our recent studies on these topics. The first one is closely related to the local structure of the metallic glasses. Therefore, our recent results on the intermediate-range local structure of the simple two Zr-based metallic glasses are described, which has been clarified by the Voronoi analysis using the experimental data of the neutron diffraction measurements. The hydrogen-induced internal friction of HMGs is also discussed on the basis of these recent results of the local structure of the metallic glasses. In terms of the second topic, the first successful preparation of heavily hydrogenated Zr-based bulk HMG rods without hydrogen-induced surface embrittlement is described. They are prepared by a powder-compact-melting and liquid-casting process using Zr-Al-Ni-Cu metallic glass and ZrH 2 powders as the starting materials. It has been found that they have high damping properties.

Influence of foaming agents on both the structure and the thermal conductivity of silicate glasses

DEFF Research Database (Denmark)

Østergaard, Martin Bonderup; Petersen, Rasmus Rosenlund; König, Jakob

Foam glass is one of the most promising insulation materials for constructions since it has low thermal conductivity, high compressive strength, non-water permeability, and high fire resistance. They can be produced using cullet sources, e.g., cathode ray tubes (CRT) panel glass, and foaming agents...... such as metal carbonates, or oxidizing transition metal oxides combined with carbonaceous sources. In this work, we mix CRT panel glass powder with different foaming agents: CaCO3 (0-4 wt%), Fe2O3 (0-6 wt%), and MnxOy (0-10 wt%). The powder mixtures are sintered in the range between the glass transition...

Production of lightweight foam glass (invited talk)

DEFF Research Database (Denmark)

Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

The foam glass production allows low cost recycling of postconsumer glass and industrial waste materials as foaming agent or as melt resource. Foam glass is commonly produced by utilising milled glass mixed with a foaming agent. The powder mixture is heat-treated to around 10^3.7 – 10^6 Pa s, which...... result in viscous sintering and subsequent foaming of the glass melt. The porous glass melt is cooled down to room temperature to freeze-in the foam structure. The resulting foam glass is applied in constructions as a light weight material to reduce load bearing capacity and as heat insulating material...... in buildings and industry. We foam panel glass from old televisions with different foaming agents. We discuss the foaming ability and the foaming mechanism of different foaming systems. We compare several studies to define a viscous window for preparing low density foam glass. However, preparing foam glass...

Recycling of nuclear fuel swarf at the fabrication of UO sub(2)-pellets and its influence on the irradiation behavior

International Nuclear Information System (INIS)

Dias, M.S.; Lameiras, F.S.; Santos, A.M.M. dos

1991-01-01

From the fabrication of UO sub(2) pellets for light water reactor fuel rods, nuclear fuel scraps results in form of UO sub(2) grinding swarf and UO sub(2) sinter scraps oxidized to U sub(3)O sub(8) powder. Detailed investigations on five types of UO sub(2) pellets fabricated with different portions of this scrap kinds added to the UO sub(2) press powder showed that there is only a small influence of such scrap additions on the irradiation behavior, especially for the fission gas release. This allows to recycle the fabrication scrap in a simple and economic way. (author)

Advanced technologies for decontamination and conversion of scrap metals

International Nuclear Information System (INIS)

Muth, T.R.; Moore, J.; Olson, D.; Mishra, B.

1994-01-01

Recycle of radioactive scrap metals (RSM) from decommissioning of DOE uranium enrichment and nuclear weapons manufacturing facilities is mandatory to recapture the value of these metals and avoid the high cost of disposal by burial. The scrap metals conversion project detailed below focuses on the contaminated nickel associated with the gaseous diffusion plants. Stainless steel can be produced in MSC's vacuum induction melting process (VIM) to the S30400 specification using nickel as an alloy constituent. Further the case alloy can be rolled in MSC's rolling mill to the mechanical property specification for S30400 demonstrating the capability to manufacture the contaminated nickel into valuable end products at a facility licensed to handle radioactive materials. Bulk removal of Technetium from scrap nickel is theoretically possible in a reasonable length of time with the high calcium fluoride flux, however the need for the high temperature creates a practical problem due to flux volatility. Bulk decontamination is possible and perhaps more desirable if nickel is alloyed with copper to lower the melting point of the alloy allowing the use of the high calcium fluoride flux. Slag decontamination processes have been suggested which have been proven technically viable at the Colorado School of Mines

Vitrification for stability of scrap and residue

Energy Technology Data Exchange (ETDEWEB)

Forsberg, C.W. [Oak Ridge National Lab., TN (United States)

1996-05-01

A conference breakout discussion was held on the subject of vitrification for stabilization of plutonium scrap and residue. This was one of four such sessions held within the vitrification workshop for participants to discuss specific subjects in further detail. The questions and issues were defined by the participants.

Glass Ceramics Composites Fabricated from Coal Fly Ash and Waste Glass

International Nuclear Information System (INIS)

Angjusheva, B.; Jovanov, V.; Srebrenkoska, V.; Fidancevska, E.

2014-01-01

Great quantities of coal ash are produced in thermal power plants which present a double problem to the society: economical and environmental. This waste is a result of burning of coal at temperatures between 1100-14500C. Fly ash available as fine powder presents a source of important oxides SiO2, Al2O3, Fe2O3, MgO, Na2O, but also consist of small amount of ecologically hazardous oxides such as Cr2O3, NiO, MnO. The combination of the fly ash with waste glass under controlled sintering procedure gave bulk glass-ceramics composite material. The principle of this procedure is presented as a multi barrier concept. Many researches have been conducted the investigations for utilization of fly ash as starting material for various glass–ceramics production. Using waste glass ecologically hazardous components are fixed at the molecular level in the silicate phase and the fabricated new glass-ceramic composites possess significantly higher mechanical properties. The aim of this investigation was to fabricate dense glass ceramic composites using fly ash and waste glass with the potential for its utilization as building material

Phase separation in an ionomer glass

DEFF Research Database (Denmark)

Pedersen, Malene Thostrup; Tian, K.V.; Dobó-Nagy, C.

2015-01-01

The G338 ionomer glass is a fluoro-alumino-silicate system, which is used as the powder component of glass ionomer cements (GICs) in dental applications. However, despite progress in understanding the nature of this glass, chemical identity of its separated amorphous phases has not yet been...... amorphous phases in G388 are Ca/Na-Al-Si-O, Ca-Al-F and Ca-P-O-F phases, respectively. However, the exact chemical compositions of the three phases still require further exploration. The results of this work are important for understanding the impact of phase separation within ionomer glasses on the setting...... conclusively determined. In this work, we identify these phases by performing differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses on both the as-received glass and heat-treated samples. We detected three glass transitions in the as-received G338 glass during DSC upscaning, implying...

Sintering behavior of LZSA glass-ceramics

Directory of Open Access Journals (Sweden)

Oscar Rubem Klegues Montedo

2009-06-01

Full Text Available The LZSA glass-ceramic system (Li2O-ZrO2-SiO2-Al2O 3 shows interesting properties, such as good chemical resistance, low thermal expansion, high abrasion resistance, and a low dielectric constant. However, in order to obtain a high performance material for specific applications, the sintering behavior must be better understood so that the porosity may be reduced and other properties improved. In this context, a sintering investigation for a specific LZSA glass-ceramic system composition was carried out. A 18.8Li2O-8.3ZrO2-64.2SiO2-8.7Al 2O3 glass was prepared by melting the solids, quenching the melt in water, and grinding the resulting solid in order to obtain a powder (3.68 μm average particle diameter. Subsequently, the glass powder was characterized (chemical analysis and determination of thermal properties and the sintering behavior was investigated using optical non-contact dilatometry measurements. The results showed that the crystallization process strongly reduced the sintering in the temperature interval from 785 to 940 °C, and a maximum thermal shrinkage of 15.4% was obtained with operating conditions of 1020 °C and 180 minutes.

Reuse of scrap of Al and steel SAE 1045 in metal composite as alternative of recycling route powder metallurgy

International Nuclear Information System (INIS)

Souza, V.E.S.; Masieiro, F.R.S.; Lourenco, J.M.; Felipe, R.C.T.S.

2009-01-01

Full text: The process of powder metallurgy in the production of parts through application of pressure on the selected ceramic or metal powders, which are subjected to a temperature of sintering for to occur consolidation of the components. The metal-mechanical industry is responsible for the generation of inputs from their manufacturing processes. This work aims to re-use of chips of Al and SAE 1045 steel by powder metallurgy of this is a viable and effective. This work is in the manufacture of a composite using Al 6060 metal matrix and steel 1045 as reinforcement (30%, 40%, 50%), under different compaction pressures (250MPa, 400MPa and 600MPa), analyzing the influence of compressibility in hardness of the compressed. The samples were sintered at a temperature of 500 ° C in an oven using resistive atmosphere of hydrogen for 45 minutes. After the procedures of the powder metallurgy technique were analyzed of the optical microscopy, x-ray diffraction, MEV and Rockwell hardness, which was found to be evaluated as not diffusibility between the steel and aluminum. (author)

Powder technological vitrification of simulated high-level waste

International Nuclear Information System (INIS)

Gahlert, S.

1988-03-01

High-level waste simulate from the reprocessing of light water reactor and fast breeder fuel was vitrified by powder technology. After denitration with formaldehyde, the simulated HLW is mixed with glass frit and simultaneously dried in an oil-heated mixer. After 'in-can calcination' for at least 24 hours at 850 or 950 K (depending on the type of waste and glass), the mixture is hot-pressed in-can for several hours at 920 or 1020 K respectively, at pressures between 0.4 and 1.0 MPa. The technology has been demonstrated inactively up to diameters of 30 cm. Leach resistance is significantly enhanced when compared to common borosilicate glasses by the utilization of glasses with higher silicon and aluminium content and lower sodium content. (orig.) [de

Hydrothermal metallurgy for recycling of slag and glass

International Nuclear Information System (INIS)

Tanaka, Toshihiro; Yoshikawa, Takeshi; Hirai, Nobumitsu; Katsuyama, Shigeru

2009-01-01

The authors have applied hydrothermal reactions to develop recycling processing of slag or glass. As an example, under hydrothermal conditions such as 200 300 deg. C and 30 40MPa with H 2 O, powders made of glass can be sintered to become solidified glass materials containing about 10mass% H 2 O. When the glass containing H 2 O is heated again under normal pressure, the glass expands releasing H 2 O to make porous microstructure. H 2 O starts to emit just above the glass transition temperature. Therefore, when we have a glass with low glass transition temperature, we can make low temperature foaming glass. The SiO 2 -Na 2 O-B 2 O 3 glass is a candidate to be such a foaming glass. In this paper, we describe our recent trial on the fabrication of the low temperature foaming glass by using hydrothermal reaction.

Scrap is no crap

DEFF Research Database (Denmark)

Wenzel, Henrik

2009-01-01

Scrap is good business for the environment. When we recycle metal - meaning to collect, sort and melt it down - we emit much less CO2 than when we extract metal from the ground. The environmental benefit applies to all metals and is gained every time we recycle them. That is a positive message in...... in a world where we search for methods to reduce our CO2 emission. And the environmental potential is big: There are no upper limits for how many times we can recycle metals, which makes recycling an important part of the fight against global warming....

Production of NdFeB powders by HDDR from sintered magnets; Obtencao de pos de NdFeB por HDDR a partir de imas sinterizados

Energy Technology Data Exchange (ETDEWEB)

Janasi, S.R.; Rodrigues, D.; Landgraf, F.J.G. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil). Lab. de Metalurgia e Materiais Ceramicos; Silva, B.F.A. da; Takiishi, H [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Campos, M.F. de [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

2010-07-01

The production of NdFeB powders by the HDDR process from metallic alloys has been widely investigated. Different HD and DR conditions have been used to induce anisotropy and to improve the intrinsic coercivity of the obtained powders. The purpose of this study is to apply the HDDR process in the reprocessing of NdFeB sintered magnet scraps. There were investigated different processing conditions as temperature and time of desorption and recombination (DR). The results of X ray diffraction show the formation of the magnetic phase Nd{sub 2}Fe{sub 14}B in all the investigated conditions. Magnetic measurements by vibrating sample magnetometer indicate that powders with intrinsic coercivity up to 790 kA/m were obtained. (author)

Solid oxide fuel cell having a glass composite seal

Science.gov (United States)

De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

2013-04-16

A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

Progress toward uranium scrap recycling via electron beam cold hearth refining

International Nuclear Information System (INIS)

McKoon, R.H.

1994-01-01

A 250 kW electron beam cold hearth refining (EBCHR) melt furnace at Lawrence Livermore National Laboratory (LLNL) has been in operation for over a year producing 5.5 in.-diameter ingots of various uranium alloys. Production of in-specification uranium-6%-niobium (U-6Nb) alloy ingots has been demonstrated using Virgin feedstock. A vibratory scrap feeder has been installed on the system and the ability to recycle chopped U-6Nb scrap has been established. A preliminary comparison of vacuum arc remelted (VAR) and electron beam (EB) melted product is presented

Progress toward uranium scrap recycling via Electron Cold Hearth Refining (EBCHR)

International Nuclear Information System (INIS)

McKoon, R.H.

1994-01-01

A 250 kW electron beam cold hearth refining (EBCHR) melt furnace at Lawrence Livermore National Laboratory (LLNL) has been in operation for over a year producing 5.5 in.-diameter ingots of various uranium alloys. Production of in-specification uranium-6% - niobium (U-6Nb) alloy ingots has been demonstrated using virgin feedstock. A vibratory scrap feeder has been installed on the system and the ability to recycle chopped U-6Nb scrap has been established. A preliminary comparison of vacuum arc remelted (VAR) and electron beam (EB) melted product is presented

The reuse of scrap and decontamination waste water from decommissioning

International Nuclear Information System (INIS)

Deng Junxian; Li Xin; Xie Xiaolong

2010-01-01

Huge amount of radioactive scrap with low activity will be generated from reactor decommissioning; the decontamination is concentrated in the surface layer of the scrap. The decontaminated substance can be removed by high pressure water jet to appear the base metal and to reuse the metal. Big amount of radioactive waste water will be generated by this decontamination technology; the radioactive of the waste water is mainly caused by the solid particle from decontamination. To remove the solid particle as clean as possible, the waste water can be reused. Different possible technology to remove the solid particle from the water had been investigated, such as the gravity deposit separation, the filtration and the centrifugal separation etc. The centrifugal separation technology is selected; it includes the hydraulic vortex, the centrifugal filtration and the centrifugal deposit. After the cost benefit analysis at last the centrifugal deposit used butterfly type separator is selected. To reuse the waste water the fresh water consumption and the cost for waste water treatment can be reduced. To reuse the radioactive scrap and the waste water from decommissioning will minimize the radioactive waste. (authors)

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

Energy Technology Data Exchange (ETDEWEB)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei [State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065 (China)

2015-05-22

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

Science.gov (United States)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

2015-05-01

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps.

Recycling and processing of several typical crosslinked polymer scraps with enhanced mechanical properties based on solid-state mechanochemical milling

International Nuclear Information System (INIS)

Lu, Canhui; Zhang, Xinxing; Zhang, Wei

2015-01-01

The partially devulcanization or de-crosslinking of ground tire rubber (GTR), post-vulcanized fluororubber scraps and crosslinked polyethylene from cable scraps through high-shear mechanochemical milling (HSMM) was conducted by a modified solid-state mechanochemical reactor. The results indicated that the HSMM treated crosslinked polymer scraps can be reprocessed as virgin rubbers or thermoplastics to produce materials with high performance. The foamed composites of low density polyethylene/GTR and the blend of post-vulcanized flurorubber (FKM) with polyacrylate rubber (ACM) with better processability and mechanical properties were obtained. The morphology observation showed that the dispersion and compatibility between de-crosslinked polymer scraps and matrix were enhanced. The results demonstrated that HSMM is a feasible alternative technology for recycling post-vulcanized or crosslinked polymer scraps

Glass-ceramics with multibarrier structure obtained from industrial waste

Energy Technology Data Exchange (ETDEWEB)

Berzina, L.; Cimdins, R.; Rozenstrauha, I. [Riga Tech. Univ. (Latvia). Fac. of Chem. Technol.; Bossert, J. [Technisches Inst.: Materialwissenschaft, Friedrich-Schiller-Univ., Jena (Germany); Kravtchenko, I. [Inst. for Problems of Material Science, Kiev (Ukraine)

1997-12-31

Recycling problem for various kind of waste is solved by processing the waste to ecological depositable products with multibarrier structure. In order to form a multibarrier structure the ecologically incompatible substances may be diluted and chemically bound until their recycling products gain a structure like natural mineral or glass (I. barrier). After that, remineralized materials are converted into a new product by melting or powder technology using an ecological compatible type of waste as a matrix phase (II. barrier). Waste which are treated this way could be applied to produce ceramic building materials and goods such as floor tiles, stone pavement and casting products. Industrial waste from the metallurgical factory in Latvia ``Liepajas metalurgs`` are metallurgical slag, filter dust, etching waste and sewage used in technologies. The main constituents of chemical compositions of these waste are: Fe, Ca, Si, Mg, Al, Mn etc. In some types of waste a small amount of ecologically risky elements such as Cr, Ni, Zr, Sn and Pb can occur. The combination of metallurgical waste with peat ashes from Riga thermal power station, oil shale ashes or glass waste under controlled sintering procedure gives bulk materials with surface or/and bulkcrystallization. The structure of glass-ceramics built this way may prevent the migration of ecologically risky elements into environment due to corrosion or friction. Physical-chemical properties and thermal behaviour (DTA, dilatometry, melting) of waste define the range of sintering for production of glass-ceramics (powder technology) and decorative glass-ceramic materials (melting and powder technology). (orig.) 5 refs.

Effect of nano clay particles on mechanical, thermal and physical behaviours of waste-glass cement mortars

International Nuclear Information System (INIS)

Aly, M.; Hashmi, M.S.J.; Olabi, A.G.; Messeiry, M.; Hussain, A.I.

2011-01-01

Highlights: → Glass powder (GP) and nano clay (NC) were used as a partial cement replacement in cement mortar (CM). → No damaging effect can be detected due to the reaction between GP and CM with particle size up to 75 μm. → Hybrid combination of GP/NC greatly improved mechanical properties and microstructure of CM. - Abstract: Worldwide, around 2.6 billion tons of cement is produced annually. This huge size of production consumes large amounts of energy and is one of the largest contributors to carbon dioxide (CO 2 ) release. Accordingly, there is a pressing demand to minimise the quantity of cement used in the concrete industry. The main challenge to this is to get durable concrete with less cement and within reasonable cost. The economic, environmental and engineering benefits of reusing ground waste-glass powder (WGP) as a partial cement replacement has been established, but low glass reactivity and the possible alkali-silica reaction (ASR) are a drawback. Recent advances in nano-technology have revealed that nano-sized particles such as nano clay (NC) have a high surface area to volume ratio that provides the potential for tremendous chemical reactivity, accelerating pozzolanic activity and hindering ASR. This paper presents a laboratory study of the properties of NC/WGP cement composites. The microstructure, ASR, fracture energy, compressive and flexural properties of cement mortars containing WGP as a cement replacement with and without NC are investigated and compared with plain matrix. In addition, the hydration of cement compounds was followed by differential thermal analysis (DTA), thermogravimetric analysis (TGA), and also X-ray diffraction (XRD). The results showed that incorporation of glass powder has a positive effect on the mechanical properties of cement mortars after 28 days of hydration. Also, the results revealed that the mechanical properties of the cement mortars with a hybrid combination of glass powder and NC were all higher than

Comparison of the corrosion behaviors of the glass-bonded sodalite ceramic waste form and reference HLW glasses

International Nuclear Information System (INIS)

Ebert, W. L.; Lewis, M. A.

1999-01-01

A glass-bonded sodalite ceramic waste form is being developed for the long-term immobilization of salt wastes that are generated during spent nuclear fuel conditioning activities. A durable waste form is prepared by hot isostatic pressing (HIP) a mixture of salt-loaded zeolite powders and glass frit. A mechanistic description of the corrosion processes is being developed to support qualification of the CWF for disposal. The initial set of characterization tests included two standard tests that have been used extensively to study the corrosion behavior of high level waste (HLW) glasses: the Material Characterization Center-1 (MCC-1) Test and the Product Consistency Test (PCT). Direct comparison of the results of tests with the reference CWF and HLW glasses indicate that the corrosion behaviors of the CWF and HLW glasses are very similar

Bending strength of glass-ceramics based on 3CaO.P2O5-SiO2-MgO glass system

International Nuclear Information System (INIS)

Daguano, J.K.M.F.; Suzuki, P.A.; Santos, C.; Fernandes, M.H.V.; Elias, C.N.

2009-01-01

In this work, the Modulus of Rupture of bioactive glass-ceramic based on 3CaO.P 2 O 5 -SiO 2 -MgO system was investigated, aiming its use in bone-restorations. The mechanical property was correlated with microstructural and crystallographic features of this material. High-purity starting-powders, CaCO 3 , SiO 2 , MgO, Ca (H 2 PO 4 ).H 2 O, were used in this study. The powders were mixed in a stoichiometric ratio, using planetary ball-mill. The suspensions were dried, sieved and melted at 1600 deg C, for 4h. The casting ones were cooled quickly until annealing temperature 700 deg C, in which remained for 2h, with controlled cooling-rate until ambient temperature. Bulks of glass were heat-treated with temperatures varying between 700 deg C and 1100 deg C, for 4h, being after that, cooled at 3 deg C/min. Bioactive glass and glass-ceramic were characterized by HRXRD (high resolution X-ray diffraction), where whitlockite was main phase. The microstructure was analyzed by scanning electronic microscopy. Modulus of Rupture was determined by four-point bending testing using specimens of 1.5 x 2 x 25 mm and glasses presented strength near to 70MPa, while glass ceramics treated at 975 deg C-4h, presented bending strength of 120MPa. (author)

Automobile scrap regulation. Give-away presents. Polluting cars and trade-in for cleaner cars

International Nuclear Information System (INIS)

Annema, J.A.

2010-01-01

A scrap regulation for old vehicles has been in place in the Netherlands for almost one year now. Has it been an effective instrument? What are the societal costs and benefits? Is it a fair regulation? Was it a good idea to introduce the car scrap regulation? The answer to all these questions is: doubtful. [nl

Recycling decontaminated scrap metal from the nuclear industry

International Nuclear Information System (INIS)

Bordas, F.

2000-01-01

The Commissariat a l'Energie Atomique (CEA) has set up a pilot program for recycling decontaminated scrap metal. In decommissioning its enriched uranium production facilities at Pierrelatte, the CEA has accumulated some 700 metric tons of scrap metal from dismantled uranium hexafluoride transport containers. The containers were decontaminated by SOCATRI at the Tricastin site, then cut up and recycled by a steelmaker. The project was submitted to the Ionizing Radiation Protection Office, the Nuclear Facilities Safety Division and the Regional Directorate for Industry, Research and Environmental Protection for approval. It was also submitted to the Ministry of Industry's Nuclear Information and Safety Council and to the Permanent Secretariat for Industrial Pollution Problems (an informational group chaired by the Prefect of the Provence Alpes-Cote d Azur region and including representatives of local and regional authorities, associations, elected officials and the media). The permit was granted for this program under the terms of a prefectorial decree stipulating additional requirements for the steelmaker, and contingent on the demonstration of full control over the operations, demonstrated traceability and the absence of any significant harmful effects. The key elements of this demonstration include the choice of operators, identification of the objects, itemization of the operations, discrimination of operators, the contractual framework of the operations, the signature of agreements by the CEA with SOCATRI and with the steelmaker, documentary monitoring of the operations, contradictory inspections and measurements, second-level inspection by the CEA/Valrho, audits of the operators and impact assessments. All the procedures of operations related to the scrap metal are described in quality assurance documents. (author)

The Influence of Home Scrap on Porosity of MgAl9Zn1 Alloy Pressure Castings

Directory of Open Access Journals (Sweden)

Konopka Z.

2017-03-01

Full Text Available The work presents the results of examinations concerning the influence of various amounts of home scrap additions on the porosity of castings made of MgAl9Zn1 alloy. The fraction of home scrap in the metal charge ranged from 0 to 100%. Castings were pressure cast by means of the hot-chamber pressure die casting machine under the industrial conditions in one of the domestic foundries. Additionally, for the purpose of comparison, the porosity of specimens cut out directly of the MgAl9Zn1 ingot alloy was also determined. The examinations consisted in the qualitative assessment of porosity by means of the optical microscopy and its quantitative determination by the method of weighting specimens in air and in water. It was found during the examination that the porosity of castings decreases with an increase in the home scrap fraction in the metal charge. The qualitative examinations confirmed the beneficial influence of the increased home scrap fraction on the porosity of castings. It was concluded that the reusing of home scrap in a foundry can be a good way of reduction of costs related to the production of pressure castings.

An innovative energy-saving in-flight melting technology and its application to glass production

Directory of Open Access Journals (Sweden)

Yaochun Yao et al

2008-01-01

Full Text Available The conventional method used for glass melting is air-fuel firing, which is inefficient, energy-intensive and time-consuming. In this study, an innovative in-flight melting technology was developed and applied to glass production for the purposes of energy conservation and environmental protection. Three types of heating sources, radio-frequency (RF plasma, a 12-phase alternating current (ac arc and an oxygen burner, were used to investigate the in-flight melting behavior of granulated powders. Results show that the melted particles are spherical with a smooth surface and compact structure. The diameter of the melted particles is about 50% of that of the original powders. The decomposition and vitrification degrees of the prepared powders decrease in the order of powders prepared by RF plasma, the 12-phase ac arc and the oxygen burner. The largest heat transfer is from RF plasma to particles, which results in the highest particle temperature (1810 °C and the greatest vitrification degree of the raw material. The high decomposition and vitrification degrees, which are achieved in milliseconds, shorten the melting and fining times of the glass considerably. Our results indicate that the proposed in-flight melting technology is a promising method for use in the glass industry.

Bioactive Glass-Ceramic Foam Scaffolds from ‘Inorganic Gel Casting’ and Sinter-Crystallization

Science.gov (United States)

Molino, Giulia; Vitale Brovarone, Chiara

2018-01-01

Highly porous bioactive glass-ceramic scaffolds were effectively fabricated by an inorganic gel casting technique, based on alkali activation and gelification, followed by viscous flow sintering. Glass powders, already known to yield a bioactive sintered glass-ceramic (CEL2) were dispersed in an alkaline solution, with partial dissolution of glass powders. The obtained glass suspensions underwent progressive hardening, by curing at low temperature (40 °C), owing to the formation of a C–S–H (calcium silicate hydrate) gel. As successful direct foaming was achieved by vigorous mechanical stirring of gelified suspensions, comprising also a surfactant. The developed cellular structures were later heat-treated at 900–1000 °C, to form CEL2 glass-ceramic foams, featuring an abundant total porosity (from 60% to 80%) and well-interconnected macro- and micro-sized cells. The developed foams possessed a compressive strength from 2.5 to 5 MPa, which is in the range of human trabecular bone strength. Therefore, CEL2 glass-ceramics can be proposed for bone substitutions. PMID:29495498

Bioactive Glass-Ceramic Foam Scaffolds from ‘Inorganic Gel Casting’ and Sinter-Crystallization

Directory of Open Access Journals (Sweden)

Hamada Elsayed

2018-02-01

Full Text Available Highly porous bioactive glass-ceramic scaffolds were effectively fabricated by an inorganic gel casting technique, based on alkali activation and gelification, followed by viscous flow sintering. Glass powders, already known to yield a bioactive sintered glass-ceramic (CEL2 were dispersed in an alkaline solution, with partial dissolution of glass powders. The obtained glass suspensions underwent progressive hardening, by curing at low temperature (40 °C, owing to the formation of a C–S–H (calcium silicate hydrate gel. As successful direct foaming was achieved by vigorous mechanical stirring of gelified suspensions, comprising also a surfactant. The developed cellular structures were later heat-treated at 900–1000 °C, to form CEL2 glass-ceramic foams, featuring an abundant total porosity (from 60% to 80% and well-interconnected macro- and micro-sized cells. The developed foams possessed a compressive strength from 2.5 to 5 MPa, which is in the range of human trabecular bone strength. Therefore, CEL2 glass-ceramics can be proposed for bone substitutions.

Ceramic fiber reinforced glass-ceramic matrix composite

Science.gov (United States)

Bansal, Narottam P. (Inventor)

1993-01-01

A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

Emergency response during the radiological control of scraps in Cuba

International Nuclear Information System (INIS)

Ramos Viltre, Enma O.; Cardenas Herrera, Juan; Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Fernandez Gomez, Isis M.; Caveda Ramos, Celia; Carrazana, Jorge; Barroso Perez, Idelisa

2008-01-01

In the last few years, in the international scene, incidents have been reported due to the presence of radioactive materials in the scrap. This reality has motivated the adoption of measures of radiological security, due to the implications that these incidents have for the public and the environment, as well as for the international trade. Among theses actions is the implementation of the radiological control of scrap, with the additional requirement that this control has to be implemented in the framework of a Quality Management Program.Taking into account the international experience, our institution designed and organized in 2002 a national service for the radiological monitoring of scrap, being the clients the main exporting and trading enterprises of this material in the country. During these years, several contaminated materials have been detected, causing incidents that activated the radiological emergency response system. In this sense, since some years ago, our country has been working in the implementation of a national and ministerial system for facing and mitigating the consequences of accidental radiological situations, conjugating efforts and wills from different national institutions with the leadership of the Center of Radiation Protection and Hygiene (CPHR) and the Center of Nuclear Security (CNSN) in correspondence with the social responsibility assigned to the them. These incidents propitiate to have not only a system of capacity and quick response oriented to limit the exposure of people, to control the sources, to mitigate the consequences of the accident and to reestablish the conditions of normality, but also a previous adequate planning that guarantees the speed and effectiveness of it. In these work the experiences reached by the specialists of the CPHR from Cuba during the occurrence of an incident in the execution of the service of radiological monitoring of scraps are exposed. (author)

The Scrap Tire Problem: A Preliminary Economic Analysis (1985)

Science.gov (United States)

The purpose of the study was to conduct a preliminary economic analysis of the social benefits of EPA action to require more appropriate disposal of scrap tires versus the social costs of such an action.

Study of Wettability of Clayey Ceramic and Fluorescent Lamp Glass Waste Powders

Science.gov (United States)

Morais, Alline Sardinha Cordeiro; Monteiro, Sergio Neves; Ribeiro, Sebastião; Sardinha, Leonardo Carneiro; Vieira, Carlos Maurício Fontes

The glass tube of spent fluorescent lamps is contaminated with mercury, which might be a serious hazard in the case of conventional recycling by melting with other glasses. A possible solution could be its incorporation into a clay body to fabricate common fired ceramics such as bricks and tiles. The objective of this work is to characterize a type of fluorescent lamp glass waste to be incorporated into a clayey ceramic. The characterization was performed in terms of wettability tests to evaluate the interaction between the surface of the clayey ceramic and glass waste as a function of the firing temperature. The results showed that the contact angle decreased with increasing temperature, reaching a value of 79°, at a temperature of 1100°C, but not sufficient to completely wet the ceramic. However, compatible chemical composition and reduction of porosity by the flow of soft glass waste between the clay particles favor the consolidation of the ceramics structure above 900°C.

Studies on the Potential of Waste Soda Lime Silica Glass in Glass Ionomer Cement Production

Directory of Open Access Journals (Sweden)

V. W. Francis Thoo

2013-01-01

Full Text Available Glass ionomer cements (GIC are produced through acid base reaction between calcium-fluoroaluminosilicate glass powder and polyacrylic acid (PAA. Soda lime silica glasses (SLS, mainly composed of silica (SiO2, have been utilized in this study as the source of SiO2 for synthesis of Ca-fluoroaluminosilicate glass. Therefore, the main objective of this study was to investigate the potential of SLS waste glass in producing GIC. Two glasses, GWX 1 (analytical grade SiO2 and GWX 2 (replacing SiO2 with waste SLS, were synthesized and then characterized using X-ray diffraction (XRD and energy dispersive X-ray (EDX. Synthesized glasses were then used to produce GIC, in which the properties were characterized using Fourier transform infrared spectroscopy (FT-IR and compressive test (from 1 to 28 days. XRD results showed that amorphous glass was produced by using SLS waste glass (GWX 2, which is similar to glass produced using analytical grade SiO2 (GWX 1. Results from FT-IR showed that the setting reaction of GWX 2 cements is slower compared to cement GWX 1. Compressive strengths for GWX 1 cements reached up to 76 MPa at 28 days, whereas GWX 2 cements showed a slightly higher value, which is 80 MPa.

Design of the network for the radiological control in the recycling of metal scrap in Cuba

International Nuclear Information System (INIS)

Dominguez Ley, Orlando; Caveda Ramos, Celia; Ramos Viltre, Enma O.; Capote Ferrera, Eduardo; Alonso Abad, Dolores; Zerquera, Juan Tomas

2008-01-01

Full text: During the last six years, the Centre of Protection and Hygiene of the Radiations (CPHR) has given answer to the problem about the presence of radioactive materials in the scrap which is exported in Cuba. The service of radioactivity measurement in scraps has reduced the risks of the occurrence of this type of events in the main import and export enterprises in Cuba. This has been carried out using few resources, a properly qualified staff and a laboratory credited by the norm ISO 17025:00. There is not the same control in the enterprises that manipulate and process metallic scrap inside the country. With the objective of extending the radiological control of the metallic scrap to the whole country, a monitoring network was designed. The design was based on the experience accumulated during the years of service to the import and export enterprises. First, It was defined the most vulnerable points in the whole recycle chain for each province, prioritizing the scrap melting plants and the longest scrap yards. All possible scenarios were identified, a quality system was also designed and implemented and a course of Radiological Protection oriented to the metallurgist technicians who are linked with the performance of this practice was elaborated. The monitoring has two phases. First, the measurements are carried out in the measurement points in each province and the transmissions of the data related to the monitored scrap loads are sent to the CPHR. The second phase is the confection of the Declaration of Conformity at the CPHR. This declaration certifies that this scrap may be processed. For the operation of this network, two software were developed and are currently used. One of them allows the control of the information in monitoring point and sends the necessary data to CPHR for the confection of the Declaration of Conformity. The other controls all the information received from the monitoring points and generates the Declaration of Conformity

Simple and environmentally friendly preparation and size control of silver nanoparticles using an inhomogeneous system with silver-containing glass powder

International Nuclear Information System (INIS)

Mori, Yasutaka; Tagawa, Toshio; Fujita, Masanori; Kuno, Toyohiko; Suzuki, Satoshi; Matsui, Takemi; Ishihara, Masayuki

2011-01-01

A simple, environmentally friendly method for preparing highly size-controlled spherical silver nanoparticles was developed that involved heating a mixture of silver-containing glass powder and an aqueous solution of glucose. The stabilizing agent for silver nanoparticles was found to be caramel, which was generated from glucose when preparing the nanoparticles. The particle size was independent of the reaction time, but it increased proportionally with the square root of the glucose concentration in the range 0.25–8.0 wt% (corresponding to particle sizes of 3.48 ± 1.83 to 20.0 ± 2.76 nm). Difference of the generation mechanism of silver nanoparticles between this inhomogeneous system and a system in which Ag + was homogeneously dispersed was discussed.

Noneconomic factors influencing scrap metal disposition decisions at DOE and NRC-licensed nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Ewen, M.D.; Robinson, L.A.

1997-02-01

The U.S. Environmental Protection Agency (EPA) is currently developing radiation protection standards for scrap metal, which will establish criteria for the unconditional clearance of scrap from nuclear facilities. In support of this effort, Industrial Economics, Incorporated is assessing the costs and benefits attributable to the rulemaking. The first step in this analysis is to develop an in-depth understanding of the factors influencing scrap disposition decisions, so that one can predict current and future practices under existing requirements and compare them to the potential effects of EPA`s rulemaking. These baseline practices are difficult to predict due to a variety of factors. First, because decommissioning activities are just beginning at many sites, current practices do not necessarily provide an accurate indicator of how these practices may evolve as site managers gain experience with related decisions. Second, a number of different regulations and policies apply to these decisions, and the interactive effects of these requirements can be difficult to predict. Third, factors other than regulatory constraints and costs may have a significant effect on related decisions, such as concerns about public perceptions. In general, research suggests that these factors tend to discourage the unconditional clearance of scrap metal.

Plasma deposition by discharge in powder

International Nuclear Information System (INIS)

El-Gamal, H.A.; El-Tayeb, H.A.; Abd El-Moniem, M.; Masoud, M.M.

2000-01-01

Different types of material powders have been fed to the breach of a coaxial discharge. The coaxial discharge is powered from a 46.26 mu F, 24 KV capacitor bank. When the discharge takes place at the breach, the powder is heated and ionized to form a sheath of its material. The plasma sheath is ejected from the discharge zone with high velocity. The plasma sheath material is deposited on a glass substrate. It has been found from scanning electron microscope (SEM) analysis that the deposited material is almost homogenous for ceramic and graphite powders. The grain size is estimated to be the order of few microns. To measure the deposited material thickness the microdensitometer and a suitable arrangement of a laser interferometer and an optical microscope are used. It has also been found that deposited material thickness depends on the discharge number of shots and the capacitor bank energy

Advanced technologies for decontamination and conversion of scrap metal

International Nuclear Information System (INIS)

MacNair, V.; Muth, T.; Shasteen, K.; Liby, A.; Hradil, G.; Mishra, B.

1996-01-01

In October 1993, Manufacturing Sciences Corporation was awarded DOE contract DE-AC21-93MC30170 to develop and test recycling of radioactive scrap metal (RSM) to high value and intermediate and final product forms. This work was conducted to help solve the problems associated with decontamination and reuse of the diffusion plant barrier nickel and other radioactively contaminated scrap metals present in the diffusion plants. Options available for disposition of the nickel include decontamination and subsequent release or recycled product manufacture for restricted end use. Both of these options are evaluated during the course of this research effort. work during phase I of this project successfully demonstrated the ability to make stainless steel from barrier nickel feed. This paved the way for restricted end use products made from stainless steel. Also, after repeated trials and studies, the inducto-slag nickel decontamination process was eliminated as a suitable alternative. Electro-refining appeared to be a promising technology for decontamination of the diffusion plant barrier material. Goals for phase II included conducting experiments to facilitate the development of an electro-refining process to separate technetium from nickel. In parallel with those activities, phase II efforts were to include the development of the necessary processes to make useful products from radioactive scrap metal. Nickel from the diffusion plants as well as stainless steel and carbon steel could be used as feed material for these products

Morphological and mechanical analyses of laminates manufactured from randomly positioned carbon fibre/epoxy resin prepreg scraps

Science.gov (United States)

Souza, Christiane S. R.; Cândido, Geraldo M.; Alves, Wellington; Marlet, José Maria F.; Rezende, Mirabel C.

2017-10-01

This study aims to contribute to sustainability by proposing the reuse of composite prepreg scrap as an added value from discards. The research evaluates the microstructure and mechanical properties of laminates processed by the reuse of uncured carbon fibre/F155-epoxy resin prepreg scraps, waste from the ply cutting area of an aeronautical industry. The composite scraps were used as collected and were randomly positioned to produce laminates to be cured at an autoclave. The mechanical characterization shows a decrease of 39% for the compression property due to the discontinuous fibres in the laminate and an increase of 34% for the interlaminar shear strength, when compared to continuous fibre laminates. This increase is attributed to the higher crosslink density of the epoxy resin, as a result of the cure temperature used in autoclave (60 °C higher than suggested by supplier) and also to the randomly positioned scraps. Microscopic analyses confirm the consolidation of laminates, although show resin rich areas with different sizes and shapes attributed to the overlapping of the scraps with different sizes and shapes. These resin rich areas may contribute to decrease the mechanical properties of laminates. The correlation between mechanical and morphological results shows potential to be used on non-critical structural application, as composite jigs, contributing to sustainability.

RECYCLING OF SCRAP AND WASTE OF COPPER AND COPPER ALLOYS IN BELARUS

Directory of Open Access Journals (Sweden)

S. L. Rovin

2017-01-01

Full Text Available The construction of a new casting and mechanical shop of unitary enterprise «Tsvetmet» in December 2015 has allowed to solve the complex problem of processing and utilization of scrap and wastes of copper and copper alloys in the Republic of Belarus. The technological processes of fire refinement of copper and manufacturing of copper rod from scrap and production of brass rod by hot pressing (extrusion of the continuously casted round billet have been mastered for the first time in the Republic of Belarus.

The effect of replaced recycled glass on thermal conductivity and compression properties of cement

Science.gov (United States)

khalil, A. S.; Mahmoud, M. A.; AL-Hathal, A.; Jawad, M. K.; Mozahim, B. M.

2018-05-01

This study deal with recycling of waste colorless glass bottles which are prepared as a powder and use them as an alternative for cement to save the environment from west and reduce some of cement(ceramic) damage and interactions with conserving physical properties of block concrete. Different weight percentage (0%, 2%, 4%, 5%, 6%, 8%, 10%, 15%, 20% and 25%) of recycled glass bottle were use in this research to be replaced by a certain percentages of cement. Thermal conductivity was studied for prepared samples. Results show that the thermal conductivity decrease with the increase of weight percentage of glass powder comparing with the stander sample.

Microstructural analysis of clayey ceramic incorporated with fluorescent lamp glass

International Nuclear Information System (INIS)

Morais, A.S.C.; Caldas, T.C.C.; Pereira, P.S.; Monteiro, S.N.; Vieira, C.M.F.

2011-01-01

This study aims to evaluate the effect of the incorporation of glass powder fluorescent lamp, from a decontamination process, in the microstructure of clayey ceramic. Formulations were prepared with incorporation of the waste in amounts of up to 10 wt.% into the clayey body. Specimens were prepared by uniaxial mold-press at 20 MPa and then fired at 850 and 1050°C. After firing, the microstructure of the ceramics was evaluated by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the incorporation of glass powder into the clayey body changes the microstructure of the ceramics. (author)

Utilization of metal scrap for the production of waste drums for ultimate disposal

International Nuclear Information System (INIS)

Janberg, K.; Rittscher, D.

1988-01-01

The contribution reviews the history of development of the techniques for treatment of decommissioning scrap from the beginning of the 1980's onwards (decommissioning of the Niederaichbach and Gundremmingen nuclear power stations), together with the radiological measuring methods required for regulatory purposes. The advantages of the recycling of the metal scrap by means of melting, and of materials utilization for production of waste containers for ultimate storage are discussed together with product quality assurance criteria. (RB) [de

Process for using lead battery scrap. Verfahren zum Verarbeiten von Bleiakkumulatorenschrott

Energy Technology Data Exchange (ETDEWEB)

Sycev, A P; Kim, G V; Larin, V F; Sidorova, G D; Vicharev, I G; Kuur, V P; Achmetov, R S; Moiseev, G L; Maslov, V I; Kabacek, V G

1986-06-26

The process for using lead battery scrap is such that it leads to an increase of lead metal without the use of fluxes for forming the melt. According to the invention, the battery scrap is broken up, dangerous parts (organic substances containing chlorine) are removed and large pieces of lead (pole bridges, grids, contact pins) are sorted out. The remainder is chopped up into pieces less than 10 mm in size. The small pieces are melted by the suspension melting process at a temperature of 1300 to 1500/sup 0/C in an oxidising atmosphere (air or oxygen) without using any fuel. As the small pieces contain parts of the battery case (= organic substances free of chlorine), they burn in air generating heat, which is then used to melt the sulphate oxide lead compounds. The previously sorted large lead parts are then added to the lead oxide melt. Finally, the lead oxide is reduced to lead metal with coke in a furnace. After the reduction of lead oxide to lead, less than 0.2% of the initial lead content in the battery scrap being processed is lost in the dumped slag.

Effective regeneration of anode material recycled from scrapped Li-ion batteries

Science.gov (United States)

Zhang, Jin; Li, Xuelei; Song, Dawei; Miao, Yanli; Song, Jishun; Zhang, Lianqi

2018-06-01

Recycling high-valuable metal elements (such as Li, Ni, Co, Al and Cu elements) from scrapped lithium ion batteries can bring significant economic benefits. However, recycling and reusing anode material has not yet attracted wide attention up to now, due to the lower added-value than the above valuable metal materials and the difficulties in regenerating process. In this paper, a novel regeneration process with significant green advance is proposed to regenerate anode material recycled from scrapped Li-ion batteries for the first time. After regenerated, most acetylene black (AB) and all the styrene butadiene rubber (SBR), carboxymethylcellulose sodium (CMC) in recycled anode material are removed, and the surface of anode material is coated with pyrolytic carbon from phenolic resin again. Finally, the regenerated anode material (graphite with coating layer, residual AB and a little CMC pyrolysis product) is obtained. As expected, all the technical indexs of regenerated anode material exceed that of a midrange graphite with the same type, and partial technical indexs are even closed to that of the unused graphite. The results indicate the effective regeneration of anode material recycled from scrapped Li-ion batteries is really achieved.

Preparation of Zr50Al15-xNi10Cu25Yx amorphous powders by mechanical alloying and thermodynamic calculation

International Nuclear Information System (INIS)

Long, Woyun; Li, Jing; Lu, Anxian

2013-01-01

Amorphous Zr 50 Al 15-x Ni 10 Cu 25 Y x powders were fabricated by mechanical alloying at a low rotation speed from commercial pure element powders. The beneficial effect of Al partially substituted by Y in Zr 50 Al 15 Ni 10 Cu 25 on glass-forming ability was investigated. The as-milled powders were characterized by X-ray diffraction and transmission electron microscopy. The results show that partial substitution of Al by Y can improve the glass-forming ability of Zr 50 Al 15 Ni 10 Cu 25 Y alloy. Thermodynamic calculation of equivalent free energy shows that Zr 50 Al 13.8 Ni 10 Cu 25 Y 1.2 alloy has the highest glass-forming ability, which is in good agreement with the report of orthogonal experiments. (author)

A recovery of gold from electronic scrap by mechanical separation, acid leaching and electrowinning

Energy Technology Data Exchange (ETDEWEB)

Rhee, K.I.; Lee, J.C.; Lee, C.K.; Joo, K.H.; Yoon, J.K.; Kang, H.R.; Kim, Y.S.; Sohn, H.J.

1995-12-31

A series of processes to recover the gold from electronic scrap which contains initially about 200--600 ppm Au have been developed. First, mechanical beneficiation including shredding, crushing and screening was employed. Results showed that 99 percent of gold component leaves in the fraction of under 1 mm of crushed scrap and its concentration was enriched to about 800 ppm without incineration. The scrap was leached in 50% aqua regia solution and gold was dissolved completely at 60 C within 2 hours. Other valuable metals such as silver, copper, nickel and iron were also dissolved. This resulting solution was boiled to remove nitrous compounds in the leachate. Finally, a newly designed electrolyzer was tested to recover the gold metal. More than 99% of gold and silver were recovered within an hour in electrowinning process.

Statistical treatment of hazards result from radioactive material in metal scrap

International Nuclear Information System (INIS)

Salem, E.F.; Rashad, S.M.

2013-01-01

Radioactive sources have a wide range of uses in medicine and industry. Radioactive materials entering the public domain in an uncontrolled manner may creating a serious risk of radiation exposure for workers and the public as well as excessive costs for plant decontamination and waste of product to be borne by the metal industry. This paper describes the major accidents that had happened in the last decades due to radioactive material in metal scrap, provides assessment of associated hazards and lessons learned. This will help Regulatory Authority to introduce measures capable to avoid the recurrence of similar events. The study highlights the situation for metal scrap incidents in Egypt.

Glass Melting under microgravity. ; Space experiment by Mori astronaut. Mujuryokuka deno glass yoyu. ; Morisan no uchu jikken

Energy Technology Data Exchange (ETDEWEB)

Makihara, M. (Osaka National Research Institute, Osaka (Japan))

1993-03-01

A space experiment on glass melting under microgravity was performed in a space shuttle in September 1992. The experiment has been intended to make glass from glass material floating in air by heating and melting it with light and an acoustic levitation furnace. The acoustic levitation furnace used in the experiment has been arranged so that a sound wave from a speaker makes a steady wave in a cylindrical quartz glass core tube with a length of 16 cm and a diameter of 4 cm, and a test sample can be retained floating in a valley of central wave pressures. The test sample retained floating has been collected and heated by light from a 500-W halogen lamp. Behavior of molten glass liquid under microgravity has been investigated. The glass material powder spheres have been melted completely and made into glass without crystallization. With regard to flows generated in the test sample placed in the acoustic levitation furnace, a glass spot containing cobalt oxide has been attached onto part of the test sample surface for observation. As a result, the spot has been incorporated in the glass without developing diffusion. 6 refs., 4 figs.

Effect of Al2O3 nano-filler on properties of glass-based seals for solid oxide fuel cells.

Science.gov (United States)

Lee, Dong Bok; Choi, Myong-Jae; Park, Sung; Lee, Jae Chun

2013-01-01

This study compares the viscosity and strength of three glass-based seals prepared with or without nano or micron-sized alumina powder used as filler material. Measurements of the viscosity and bending strength of the glass-based seals showed that addition of the nano-sized alumina powder to the glass increased both the high-temperature viscosity and the strength of the sintered glass matrix. Strength tests and observations of the microstructure of the fracture surface of the seal samples confirmed the strengthening of the glass network structure. Conversion of non-bridging oxygen to bridging oxygen is presumed to occur upon the addition of alumina to the glass sample. The strengthening of the alumina-glass composite seal was attributed to the alumina nano-filler and prolonged heat treatment at elevated temperatures.

Development of a fused glass disc XRF facility and comparison with the pressed powder pellet technique at Instituto de Geociencias, Sao Paulo University, Brazil

Energy Technology Data Exchange (ETDEWEB)

Mori, Paulo Ernesto; Correia, Ciro Teixeira [Sao Paulo Univ., SP (Brazil). Dept. of Mineralogia e Geotectonia; Reeves, Shane [Melbourne Univ., Parkville, VIC (Australia). School of Earth Sciences; Haukka, Maunu [Melbourne Univ., Parkville, VIC (Australia). Dept. of Chemical Engineering

1999-09-01

An X-ray fluorescence spectrometry pressed powder pellet technique (PPP) currently in use at the X-ray facility of the Instituto de Geociencias, Sao Paulo University has been extended to include additional elements and complemented by a full major and trace element calibration by fused glass disc X-ray fluorescence. A total of 38 major and trace elements are available (F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Sn, Sb, Ba, Pb, Bi, La, Ce, Nd, Th and U) with variable detection limits, but generally below 10 ppm for trace elements. Loss-on-ignitions determined by weight difference and totals provide extremely good control on data quality. A full analysis, including background, matrix correction and all relevant corrections can be achieved automatically in less than 60 minutes. Virtually any sample matrix can be accommodated. The data support the view that fused disc and power pellet techniques are complementary and together provide a definite, rigorous XRF analysis. However, both techniques require considerable attention to details, with the glass disc technique prone to losses of F and S and increase detection limits for certain elements. The powder pellet technique requires fine micronizing and caution when dealing with the light elements Si and Al. Additionally the paper presents a new, previously unpublished experimentally determined Alpha coefficients for all matrix-corrected elements, which are based on the lithium metaborate system and contrast with the Philips theoretical alpha coefficients. (author)

Development of a fused glass disc XRF facility and comparison with the pressed powder pellet technique at Instituto de Geociencias, Sao Paulo University, Brazil

International Nuclear Information System (INIS)

Mori, Paulo Ernesto; Correia, Ciro Teixeira; Reeves, Shane; Haukka, Maunu

1999-01-01

An X-ray fluorescence spectrometry pressed powder pellet technique (PPP) currently in use at the X-ray facility of the Instituto de Geociencias, Sao Paulo University has been extended to include additional elements and complemented by a full major and trace element calibration by fused glass disc X-ray fluorescence. A total of 38 major and trace elements are available (F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Sn, Sb, Ba, Pb, Bi, La, Ce, Nd, Th and U) with variable detection limits, but generally below 10 ppm for trace elements. Loss-on-ignitions determined by weight difference and totals provide extremely good control on data quality. A full analysis, including background, matrix correction and all relevant corrections can be achieved automatically in less than 60 minutes. Virtually any sample matrix can be accommodated. The data support the view that fused disc and power pellet techniques are complementary and together provide a definite, rigorous XRF analysis. However, both techniques require considerable attention to details, with the glass disc technique prone to losses of F and S and increase detection limits for certain elements. The powder pellet technique requires fine micronizing and caution when dealing with the light elements Si and Al. Additionally the paper presents a new, previously unpublished experimentally determined Alpha coefficients for all matrix-corrected elements, which are based on the lithium metaborate system and contrast with the Philips theoretical alpha coefficients. (author)

Immobilization of Uranium Silicide in Sintered Iron-Phosphate Glass

International Nuclear Information System (INIS)

Mateos, Patricia; Russo, Diego; Rodriguez, Diego; Heredia, A; Sanfilippo, M.; Sterba, Mario

2003-01-01

This work is a continuation of a previous one performed in vitrification of uranium silicide in borosilicate and iron-silicate glasses, by sintering.We present the results obtained with an iron-phosphate glass developed at our laboratory and we compare this results with those obtained with the above mentioned glasses. The main objective was to develop a method as simple as possible, so as to get a monolithic glass block with the appropriate properties to be disposed in a deep geological repository.The thermal transformation of the uranium silicide was characterized by DTA/TG analysis and X-ray diffraction.We determined the evolution of the crystalline phases and the change in weight.Calcined uranium silicide was mixed with natural U 3 O 8 , the amount of U 3 O 8 was calculated to simulate an isotopic dilution of 4%.This material was mixed with powdered iron-phosphate glass (in wt.%: 64,9 P 2 O 5 ; 22,7 Fe 2 O 3 ; 8,1 Al 2 O 3 ; 4,3 Na 2 O) in different proportions (in wt%): 7%, 10% y 15%.The powders were pressed and sintered at temperatures between 585 y 670 °C. Samples of the sintered pellet were prepared for the lixiviation tests (MCC-1P: monolithic samples; deionised water; 90° C; 7, 14 and 28 days).The samples showed a quite good durability (0,6 g.m -2 .day -1 ), similar to borosilicate glasses.The microstructure of the glass samples showed that the uranium particles are much better integrated to the glass matrix in the iron-phosphate glasses than in the borosilicate or iron-silicate glasses.We can conclude that the sintered product obtained could be a good alternative for the immobilization of nuclear wastes with high content of uranium, as the ones arising from the conditioning of research reactors spent fuels

Ceramic fiber-reinforced monoclinic celsian phase glass-ceramic matrix composite material

Science.gov (United States)

Bansal, Narottam P. (Inventor); Dicarlo, James A. (Inventor)

1994-01-01

A hyridopolysilazane-derived ceramic fiber reinforced monoclinic celsian phase barium aluminum silicate glass-ceramic matrix composite material is prepared by ball-milling an aqueous slurry of BAS glass powder and fine monoclinic celsian seeds. The fibers improve the mechanical strength and fracture toughness and with the matrix provide superior dielectric properties.

EFFECTOF ISOLATION WALL USING SCRAP TIRE ON GROUND VIBRATION REDUCTION

Science.gov (United States)

Kashimoto, Takahiko; Kashimoto, Yusuke; Hayakawa, Kiyoshi; Matsui, Tamotsu; Fujimoto, Hiroaki

Some countermeasure methods against the environmental ground vibration caused by some traffic vibrations have been proposed so far. The authors have developed a new type ground vibration isolation wall using scrap tire, and evaluated its effectiveness on the ground vibration reduction by full scale field tests. In this paper, the authors discussed and examined the effectiveness of the developed countermeasure method by two field tests. The one concerns on the effect of scrap tire as soft material of vibration isolation wall, and the other on the effect of the developed countermeasure method practically applied in a residential area close to monorail traffic. As the results, it was elucidated that the ground vibration of 2-3 dB was reduced in case of two times volume of the soft material, the conversion ratio of the vibration energy of the soft material to the kinetic energy was higher than that of the core material of PHC pile, the vibration acceleration of 0.19 - 1.26 gal was reduced by the developed countermeasure method in case of the monorail traffic, and the vibration reduction measured behind the isolation wall agreed well with the proposed theoretical value, together with confirming the effectiveness of the ground vibration isolation wall using scrap tire as the countermeasure method against the environmental ground vibration.

Radiation protection aspects of the trafficking radionuclides contaminated metal scrap

International Nuclear Information System (INIS)

Prouza, Z.

1999-01-01

This paper covers the legal base of the release in the environment of radionuclides containing materials and the radiation protection aspects of trafficking in radionuclides contaminated materials. Materials, substance and objects containing radionuclides or contaminated by them may be released into the environment, if they do not exceed values authorized by SONS (State Office of Nuclear Safety). Legislative measures should be taken against illicit trafficking of the nuclear material in all the areas. The creation of a sophisticated system for the control and regulation of all important radionuclides released into the environment should be based on the radiation protection limits, constraints, reference and exemption levels which are introduced in the legislative documents; the strong supervision of producers and users of the sealed sources by SONS side, in addition to the requirements of the licensing process of their sources; a complete data-base and information exchange system related to illicit trafficking in contaminated material; in this system all the authorities with jurisdiction should be involved. The responsibilities of the persons involved in metal scrap trafficking should include arrangement of appropriate monitoring, rules for transport of the metal scrap, an adequate measuring system to monitor metal scrap including monitoring to prevent processing or smelting of the radioactive material, control measures, etc. All of the above items of legislation are an important challenge for the Czech Republic. (author)

Use of Portal Monitors for Detection of Technogenic Radioactive Sources in Scrap Metal

Science.gov (United States)

Solovev, D. B.; Merkusheva, A. E.

2017-11-01

The article considers the features of organization of scrap-metal primary radiation control on the specialized enterprises engaging in its deep processing and storage at using by primary technical equipment - radiation portal monitors. The issue of this direction relevance, validity of radiation control implementation with the use of radiation portal monitors, physical and organizational bases of radiation control are considered in detail. The emphasis is put on the considerable increase in the number of technogenic radioactive sources detected in scrap-metal that results in the entering into exploitation of radioactive metallic structures as different building wares. One of reasons of such increase of the number of technogenic radioactive sources getting for processing with scrap-metal is the absence of any recommendations on the radiation portal monitors exploitation. The practical division of the article offers to recommendation on tuning of the modes of work of radiation portal monitors depending on influence the weather factor thus allowing to considerably increase the percent of technogenic radioactive sources detection.

PRODUCTION OF ELECTROTECHNICAL WIRE OF SCRAP AND COPPER WASTES

Directory of Open Access Journals (Sweden)

I. P. Volchok

2006-01-01

Full Text Available Chemical composition, structure and properties of copper upon base steps of wire production technology (melting of anode copper with using of scrap and waste, electrolitical refining, producing of rod by continuous casting, manufacture of electrotechnical wire and fibres is described.

Mechanical behavior of cellular borosilicate glass with pressurized Ar-filled closed pores

International Nuclear Information System (INIS)

Wang Bo; Matsumaru, Koji; Yang Jianfeng; Fu Zhengyi; Ishizaki, Kozo

2012-01-01

High strength borosilicate foams were fabricated by melting glass powder under high-pressure argon gas and subsequent heat treatment of the glass bulk at atmospheric pressure. In the first step, borosilicate glass powder was melted at 1100 °C for 1 h by capsule-free hot isostatic pressing (HIPing) under a high gas pressure of 10–70 MPa. Pressurized Ar-filled spherical pores were introduced into the glass, and argon atoms were dissolved in the glass network structure. The expansion of argon-filled pores and the release of the dissolved Ar gas resulted in the formation of pressurized Ar-filled closed pores by isothermal heat treatment at 800 °C for 10 min. A high porosity of up to 80% with a bimodal distribution of micro-size cells was obtained for the resultant cellular borosilicate glass. By increasing the total gas pressure from 10 to 70 MPa, the compressive strength and the Young’s modulus were increased considerably from 15 to 52 MPa and from 4.1 to 12.6 GPa, respectively, which can be substantially attributed to the high collapse stress from the high enclosed gas pressure. The cellular glass with a high porosity showed a large failure strain under uniaxial compression.

Study of glass-nanocomposite and glass-ceramic containing ferroelectric phase

Energy Technology Data Exchange (ETDEWEB)

Abdel-Khalek, E.K., E-mail: Eid_khalaf0@yahoo.com [Department of Physics, Faculty of Science, Al Azhar University, Nasr City 11884, Cairo (Egypt); Mohamed, E.A. [Department of Physics, Faculty of Science (Girl' s Branch), Al Azhar University, Nasr City, Cairo (Egypt); Salem, Shaaban M.; Ebrahim, F.M.; Kashif, I. [Department of Physics, Faculty of Science, Al Azhar University, Nasr City 11884, Cairo (Egypt)

2012-03-15

Highlights: Black-Right-Pointing-Pointer Glass nanocomposites was synthesized. Black-Right-Pointing-Pointer Glass nanocomposites exhibit both optical transmission bands at 598 and 660 nm and broad dielectric anomalies. Black-Right-Pointing-Pointer The ferroelectricity in pure single-phase oxide glass has not yet been discovered. - Abstract: Transparent glass nanocomposite in the pseudo binary system (100 - x) Li{sub 2}B{sub 4}O{sub 7}-xBaTiO{sub 3} with x = 0 and 60 (in mol%) were prepared. Amorphous and glassy characteristics of the as-prepared samples were established via X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) respectively. The precipitated BaTiO{sub 3} nanocrystal phase embedded in the glass sample at x = 60 mol% was identified by transmission electron microscopic (TEM). The optical transmission bands at 598 and 660 nm were assigned to Ti{sup 3+} ions in tetragonal distorted octahedral sites. The precipitated Li{sub 2}B{sub 4}O{sub 7}, BaTi(BO{sub 3}){sub 2} and BaTiO{sub 3} nanocrystallites phases with heat-treatment at 923 K for 6 h (HT923) in glass-ceramic were identified by XRD, TEM and infrared absorption spectroscopy. The as-prepared at x = 60 mol% and the HT923 samples exhibit broad dielectric anomalies in the vicinity of the ferroelectric-to-paraelectric transition temperature. The results demonstrate that the method presented may be an effective way to fabricate ferroelectric host and development of multifunctional ferroelectrics.

Lead and copper removal from aqueous solutions by porous glass derived calcium hydroxyapatite

International Nuclear Information System (INIS)

Liang Wen; Zhan Lei; Piao Longhua; Ruessel, Christian

2011-01-01

Graphical abstract: . Adsorption of Pb 2+ increases with the increase in NaCl volume percentage (1:0%, 2:30%, 3:40%, 4:40%) of the Glass Derived Hydroxyapatite and reaches equilibrium after 24 h. Highlights: → Novel porous glass derived hydroxyapatite matrix is prepared. → Glass derived hydroxyapatite matrix adsorbs lead and copper ions in solutions effectively. → Two adsorption mechanisms including ion exchange theory and the dissolution and precipitation theory are involved in removal of the heavy metal ions from the solutions. - Abstract: A porous glass was prepared by sintering Na 2 O-CaO-B 2 O 3 glass powder with powdered sodium chloride. Subsequently, the sodium chloride was dissolved in water resulting in a highly porous material. A sample was prepared consisting of 60 vol% glass and 40 vol% salt which both had particle sizes 2 HPO 4 solutions at room temperature for 1 day. The porous glass derived hydroxyapatite matrix was then processed for removing lead and copper ions from aqueous solutions. The results showed that the glass derived calcium hydroxyapatite matrix effectively immobilizes lead and copper ions in solution. The adsorption mechanism was investigated by the X-ray Diffraction (XRD) and Scanning Electron Microscopy including Energy Dispersive X-Ray Spectrometry (SEM-EDX).

Developing methods for detecting radioactive scrap

International Nuclear Information System (INIS)

Bellian, J.G.; Johnston, J.G.

1995-01-01

During the last 10 years, there have been major developments in radiation detection systems used for catching shielded radioactive sources in scrap metal. The original testing required to determine the extent of the problem and the preliminary designs of the first instruments will be discussed. Present systems available today will be described listing their advantages and disadvantages. In conclusion, the newest developments and state of the art equipment will also be included describing the limits and most appropriate locations for the systems

Assignment of Responsibilities in the Management of Scrap Metal in Brazil

Energy Technology Data Exchange (ETDEWEB)

Costa, E.L., E-mail: evaldo@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro (Brazil)

2011-07-15

This paper gives an overview of the activities of the National Commission of Nuclear Energy (CNEN), as the Brazilian regulatory authority responsible for licensing, inspecting, controlling and regulating all practices involving sources of ionizing radiation. The activities of the main departments of CNEN responsible for taking care of the practices and sources are described, especially those related to orphan sources and radioactive material in scrap metal. Finally, although Brazil does not yet have the necessary infrastructure to take care of the scrap metal issue, through the joint action of the relevant departments of CNEN it is hoped that the appropriate steps can be taken to build a national protocol, following the examples of other countries, especially Spain. (author)

Analysis of Influence of Foaming Mixture Components on Structure and Properties of Foam Glass

Science.gov (United States)

Karandashova, N. S.; Goltsman, B. M.; Yatsenko, E. A.

2017-11-01

It is recommended to use high-quality thermal insulation materials to increase the energy efficiency of buildings. One of the best thermal insulation materials is foam glass - durable, porous material that is resistant to almost any effect of substance. Glass foaming is a complex process depending on the foaming mode and the initial mixture composition. This paper discusses the influence of all components of the mixture - glass powder, foaming agent, enveloping material and water - on the foam glass structure. It was determined that glass powder is the basis of the future material. A foaming agent forms a gas phase in the process of thermal decomposition. This aforementioned gas foams the viscous glass mass. The unreacted residue thus changes a colour of the material. The enveloping agent slows the foaming agent decomposition preventing its premature burning out and, in addition, helps to accelerate the sintering of glass particles. The introduction of water reduces the viscosity of the foaming mixture making it evenly distributed and also promotes the formation of water gas that additionally foams the glass mass. The optimal composition for producing the foam glass with the density of 150 kg/m3 is defined according to the results of the research.

Electroactive thermoset shape memory polymer nanocomposite filled with nanocarbon powders

International Nuclear Information System (INIS)

Leng, Jinsong; Lan, Xin; Liu, Yanju; Du, Shanyi

2009-01-01

This paper concerns an electroactive thermoset styrene-based shape memory polymer (SMP) nanocomposite filled with nanosized (30 nm) carbon powders. With an increase of the incorporated nanocarbon powders of the SMP composite, its glass transition temperature (T g ) decreases and storage modulus increases. Due to the high micro-porosity and homogeneous distributions of nanocarbon powders in the SMP matrix, the SMP composite shows good electrical conductivity with a percolation of about 3.8%. This percolation threshold is slightly lower than that of many other carbon-based conductive polymer composites. Consequently, due to the relatively high electrical conductivity, a sample filled with 10 vol% nanocarbon powders shows a good electroactive shape recovery performance heating by a voltage of 30 V above a transition temperature of 56–69 °C

Fernald scrap metal and recycling and beneficial reuse

International Nuclear Information System (INIS)

Motl, G.P.

1993-01-01

The Fernald plant, formerly known as the Feed Materials Production Facility, is located on a 1050-acre site 17 miles northwest of downtown Cincinnati, Ohio. Site construction was initiated in 1951 to fabricate uranium metal to meet defense production requirements of the U.S. Department of Energy (DOE). In October 1990, the DOE transferred management responsibility for the site from its Defense Programs organization to the Office of Environmental Restoration and Waste Management. In August 1991, the site was renamed the Fernald Environmental Management Project (FEMP) to reflect the site's new cleanup mission. During 40 yr of plant operation, a scrap metal storage area grew to contain 5000 t of scrap metal. Material in the pile, such as structural steel, crushed drums, tanks, and pipes, is contaminated with uranium to levels up to 200,000 disintegrations per minute alpha. In July 1991, cleanup of this pile was designated a CERCLA removal action under the Comprehensive Environmental Response, Compensation, and Liability Act and a consent agreement executed between the DOE and the U.S. Environmental Protection Agency

Development of iodine waste forms using low-temperature sintering glass

International Nuclear Information System (INIS)

Krumhansl, James Lee; Nenoff, Tina Maria; Garino, Terry J.; Rademacher, David

2010-01-01

This presentation will describe our recent work on the use of low temperature-sintering glass powders mixed with either AgI or AgI-zeolite to produce a stable waste form. Radioactive iodine ( 129 I, half-life of 1.6 x 10 7 years) is generated in the nuclear fuel cycle and is of particular concern due to its extremely long half-life and its effects on human health. As part of the DOE/NE Advanced Fuel Cycle Initiative (AFCI), the separation of 129 I from spent fuel during fuel reprocessing is being studied. In the spent fuel reprocessing scheme under consideration, the iodine is released in gaseous form and collected using Ag-loaded zeolites, to form AgI. Although AgI has extremely low solubility in water, it has a relatively high vapor pressure at moderate temperatures (>550 C), thus limiting the thermal processing. Because of this, immobilization using borosilicate glass is not feasible. Therefore, a bismuth oxide-based glasses are being studied due to the low solubility of bismuth oxide in aqueous solution at pH > 7. These waste forms were processed at 500 C, where AgI volatility is low but the glass powder is able to first densify by viscous sintering and then crystallize. Since the glass is not melted, a more chemically stable glass can be used. The AgI-glass mixture was found to have high iodine leach resistance in these initial studies.

Tamper-indicating device having a glass body

Science.gov (United States)

Johnston, Roger G.; Garcia, Anthony R. E.

2003-04-29

A tamper-indicating device is described. The device has a first glass body member and a second glass body member that are attached to each other through a hasp. The glass body members of the device can be tempered. The body members can be configured with hollow volumes into which powders, microparticles, liquids, gels, or combinations thereof are sealed. The choice, the amount, and the location of these materials can produce a visible, band pattern to provide each body member with a unique fingerprint identifier, which makes it extremely difficult to repair or replace once it is damaged in order to avoid tamper detection.

Yttrium aluminum garnet coating on glass substrate

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J., E-mail: eduardo.nassar@unifran.edu.br

2016-02-15

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu{sup 3+} onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min{sup −1} and evaporation led to deposition of different numbers of layers of the YAG:Eu{sup 3+} film onto the glass substrate from a YAG:Eu{sup 3+} powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu{sup 3+}. • The matrix was deposited as transparent films. • The YAG:Eu{sup 3+} was deposited by sol–gel process onto glass substrate.

Yttrium aluminum garnet coating on glass substrate

International Nuclear Information System (INIS)

Ferreira, Camila M.A.; Freiria, Gabriela S.; Faria, Emerson H. de; Rocha, Lucas A.; Ciuffi, Katia J.; Nassar, Eduardo J.

2016-01-01

Thin luminescent films have seen great technological advances and are applicable in the production of a variety of materials such as sensors, solar cells, photovoltaic devices, optical magnetic readers, waveguides, lasers, and recorders. Systems that contain yttrium aluminum oxide are important hosts for lanthanide ions and serve as light emission devices. This work deals with the deposition of yttrium aluminum garnet (YAG) film doped with Eu 3+ onto a glass substrate obtained by the sol–gel methodology. Spray pyrolysis furnished the yttrium aluminum oxide powder. Dip-coating at a withdrawal speed of 10 mm min −1 and evaporation led to deposition of different numbers of layers of the YAG:Eu 3+ film onto the glass substrate from a YAG:Eu 3+ powder suspension containing ethanol, water, and tetraethylorthosilicate. Photoluminescence, X-ray diffraction, scanning electron microscopy, and transparency measurements aided film characterization. The emission spectra revealed that the number of layers influenced film properties. - Highlights: • The spray pyrolysis was used to obtain luminescent YAG:Eu 3+ . • The matrix was deposited as transparent films. • The YAG:Eu 3+ was deposited by sol–gel process onto glass substrate.

Properties of glass-bonded zeolite monoliths

International Nuclear Information System (INIS)

Lewis, M.A.; Fischer, D.F.; Murphy, C.D.

1994-01-01

It has been shown that mineral waste forms can be used to immobilize waste salt generated during the pyrochemical processing of spent fuel from the Integral Fast Reactor (IFR). Solid, leach resistant monoliths were formed by hot-pressing mixtures of salt-occluded zeolite A powders and glass frit at 990 K and 28 MPa. Additional samples have now been fabricated and tested. Normalized release rates for all elements, including iodide and chloride, were less than 1 g/m 2 d in 28-day tests in deionized water and in brine at 363 K (90 degrees C). Preliminary results indicate that these rates fall with time with both leachants and that the zeolite phase in the glass-bonded zeolite does not function as an ion exchanger. Some material properties were measured. The Poisson ratio and Young's modulus were slightly smaller in glass-bonded zeolite than in borosilicate glass. Density depended on zeolite fraction. The glass-bonded zeolite represents a promising mineral waste form for IFR salt

A Glass-Ceramic Waste Forms for the Immobilization of Rare Earth Oxides from the Pyroprocessing Waste salt

International Nuclear Information System (INIS)

Ahn, Byung-Gil; Park, Hwan-Seo; Kim, Hwan-Young; Kim, In-Tae

2008-01-01

The fission product of rare earth (RE) oxide wastes are generates during the pyroprocess . Borosilicate glass or some ceramic materials such as monazite, apatite or sodium zirconium phosphate (NZP) have been a prospective host matrix through lots of experimental results. Silicate glasses have long been the preferred waste form for the immobilization of HLW. In immobilization of the RE oxides, the developed process on an industrial scale involves their incorporation into a glass matrix, by melting under 1200 ∼ 1300 .deg. C. Instead of the melting process, glass powder sintering is lower temperature (∼ 900 .deg. C) required for the process which implies less demanding conditions for the equipment and a less evaporation of volatile radionuclides. This study reports the behaviors, direct vitrification of RE oxides with glass frit, glass powder sintering of REceramic with glass frit, formation of RE-apatite (or REmonazite) ceramic according to reaction temperature, and the leach resistance of the solidified waste forms

Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

Energy Technology Data Exchange (ETDEWEB)

Bellucci, Devis, E-mail: devis.bellucci@unimore.it [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Sola, Antonella [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy); Cacciotti, Ilaria [University of Rome " Niccolò Cusano" , UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy); Bartoli, Cristina; Gazzarri, Matteo [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Bianco, Alessandra [Department of Enterprise Engineering, INSTM RU “Rome-Tor Vergata”, Via del Politecnico 1, 00133 Roma (Italy); Chiellini, Federica [Department of Chemistry and Industrial Chemistry, University of Pisa, UdR INSTM — Pisa, Via Risorgimento 35, 56127 Pisa (Italy); Cannillo, Valeria [Department of Engineering “E. Ferrari”, University of Modena and Reggio Emilia, Via Vignolese 905, 41125 Modena (Italy)

2014-09-01

Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG{sub C}a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG{sub C}a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg{sup 2+} and Sr{sup 2+} ions.

Mg- and/or Sr-doped tricalcium phosphate/bioactive glass composites: Synthesis, microstructure and biological responsiveness

International Nuclear Information System (INIS)

Bellucci, Devis; Sola, Antonella; Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" data-affiliation=" (University of Rome Niccolò Cusano, UdR INSTM, Via Don Carlo Gnocchi 3, 00166, Rome (Italy))" >Cacciotti, Ilaria; Bartoli, Cristina; Gazzarri, Matteo; Bianco, Alessandra; Chiellini, Federica; Cannillo, Valeria

2014-01-01

Presently, there is an increasing interest towards the composites of calcium phosphates, especially β-tricalcium phosphate (TCP), and bioactive glasses. In the present contribution, the recently developed BG C a/Mix glass has been used because its low tendency to crystallize allows to sinter the composites at relatively low temperature (i.e. 850 °C), thus minimizing the glass devitrification and the interaction with TCP. A further improvement is the introduction of lab-produced TCP powders doped with specific ions instead of non-doped commercial powders, since the biological properties of materials for bone replacement can be modulated by doping them with certain metallic ions, such as Mg and Sr. Therefore, novel binary composites have been produced by sintering the BG C a/Mix glass with the addition of pure, Mg-substituted, Sr-substituted or Mg/Sr bisubstituted TCP powders. After an accurate characterization of the starting TCP powders and of the obtained samples, the composites have been used as three-dimensional supports for the culture of mouse calvaria-derived pre-osteoblastic cells. The samples supported cell adhesion and proliferation and induced promising mechanisms of differentiation towards an osteoblastic phenotype. In particular, the Mg/Sr bi-doped samples seemed to better promote the differentiation process thus suggesting a combined stimulatory effect of Mg 2+ and Sr 2+ ions

The radiological monitoring protocol for metallic products and cleared scrap management

International Nuclear Information System (INIS)

Gil Lopez, E.

2003-01-01

Event though the use of nuclear and radiological techniques is subject to strict controls in most countries, the presence of radioactive material in batches of metallic scrap has been detected with relative frequency in the last few years. This circumstance has motivated the implementation of a series of national and international initiatives aimed at detecting and preventing this type of events, whether they be intentional or involuntary. The Spanish iron and steel industry is one of the country's most important industrial sectors, and to a great extent it depends on the importation of a very significant amount of metallic scrap that it uses as raw material. Experience has shown that countries that import large amounts of scrap, apart from supporting the mentioned international initiatives, should complement them with other national initiatives to reduce the risks resulting from the presence of radioactive material in scrap. In this context, the Spanish authorities, together with trade unions and entrepreneurial associations in the metal reclamations and smelting sectors and ENRESA, have signed a voluntary Protocol that defines and implements a national radiological monitoring and control system for scrap materials and their byproducts. The Protocol defines the obligations and rights of the signatories, and it describes the monitoring and control system and its legal bases, the operation of both specific and other general-purpose radiological monitoring equipment that existed prior to this initiative, the development of radiological training and dissemination plans for professionals in the metal reclamation and smelting sectors, the establishment of effective systems for the safe management of any radioactive materials detected, and the general improvement of the national response system in the event of radiological emergencies. Since the Protocol took effect in November 1999, more than 100 enterprises from the metallurgical (steel, copper, lead and aluminum

Efficient recovery of gold and other noble metals from electronic and other scraps

Energy Technology Data Exchange (ETDEWEB)

Baba, Hidetoshi

1987-01-01

Pure gold is extracted from crude gold by the solvent extraction method in the recovery and refining process for Noble metals recovered from electronic and other scraps. This solvent extraction method is advantageous in that it facilitates rapid processing, thereby reducing the interest burden of gold staying too long in the unit. Therefore, the method is also used in the refining of platinum and palladium. Technological innovation has created more complex and diversified types of scraps, and efforts are being made to accommodate ourselves to such a trend.

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)

Spectroscopy of Yb-doped tungsten-tellurite glass and assessment of its lasing properties

Science.gov (United States)

Merzliakov, M. A.; Kouhar, V. V.; Malashkevich, G. E.; Pestryakov, E. V.

2018-01-01

Glasses of the TeO2-WO3-Yb2O3 system are synthesized for wide range of Yb3+ concentrations of up to 6.0 × 1021 ions/cm3. The spectral-luminescent properties of lightly doped samples are investigated at room temperature and at the boiling point of liquid nitrogen. The energies of the Stark levels of the ground and excited states of Yb3+ ions incorporated into tungsten-tellurite glass are determined by analyzing the low-temperature spectra. The absorption, emission, and gain cross section spectra are obtained. The excess of the measured fluorescence decay time over the radiative lifetime ∼0.3 ms derived from the absorption spectra is attributed to the reabsorption effect in bulk samples. Measurements of lightly doped glass powder in the immersion liquid are made to reduce the effect of reabsorption. The fluorescence decay time of the powder is very close to the calculated radiative lifetime. Compared with phosphate, silicate, and other Yb3+-doped glasses, the tungsten-tellurite glass has a promising potential as a gain medium for lasers and amplifiers.

MoO3 incorporation in magnesium aluminosilicate glasses

International Nuclear Information System (INIS)

Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

2015-01-01

Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO 3 ) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO 3 can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO 3 increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO 4 2− units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO 4

Development of an integrated MOX-scrap recycling flow-sheet by dry and wet routes using microwave heating techniques

Energy Technology Data Exchange (ETDEWEB)

Mallik, G K; Malav, R K; Karande, A P; Bhargava, V K; Kamath, H S [Advanced Fuel Fabrication Facility, Bhabha Atomic Research Centre, Tarapur (India)

1999-01-01

A simple, short and efficient scrap, recycling flow-sheet, which is exclusively based on microwave heating techniques and, includes both dry and wet routes, for (U,Pu)O{sub 2} fuel scrap recycling has been developed and evaluated. (author) 6 refs., 1 tab.

Preliminary study in development of glass-ceramic based on SiO{sub 2}-LiO{sub 2} system, starting of different SiO{sub 2} starting powders; Um estudo preliminar do desenvolvimento de materiais vitroceramicos do sistema SiO{sub 2}-LiO{sub 2} obtidos a partir de diferentes fontes de silica

Energy Technology Data Exchange (ETDEWEB)

Daguano, J.K.M.F.; Santos, F.A.; Santos, C.; Marton, L.F.M.; Conte, R.A.; Rodrigues Junior, D. [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Escola de Engenharia de Lorena. Dept. de Materiais; Melo, F.C.L. [Centro Tecnico Aeroespacial (AMR/CTA/IAE), Sao Jose dos Campos, SP (Brazil). Instituto de Aeronautica e Espaco. Div. de Materiais

2009-07-01

In this work, lithium disilicate glass-ceramics were developed starting of the rice ash- SiO{sub 2} and Li{sub 2}CO{sub 3} powders. The results were compared with glass ceramics based on the lithium disilicate obtained by commercial SiO{sub 2} powders. Glass were melted at 1580 deg C, and annealed at 850 deg C. X-Ray diffraction and scanning electron microscopy were used for characterization of the materials, and hardness and fracture toughness were evaluated using Vickers indentation method. Glasses with amorphous structure were obtained in both materials. After annealing, 'rice-ash' samples presented Li{sub 2}SiO{sub 3} and residual SiO{sub 2} as crystalline phases. On the other side, commercial SiO{sub 2}- Samples presented only Li{sub 2}Si{sub 2}O{sub 5} as crystalline phases and the better results of hardness and fracture toughness. (author)

Detecting the presence of abnormal radioactivity in scrap using the statistical method

International Nuclear Information System (INIS)

Baillet, G.

1999-01-01

The radiological protection criteria recommended for recycling of metals (as in the paper 'Radiation protection 89') cannot be used when scrap is checked on arrival at steel plants. In the event of an incident, neither the nature of the radioelements that may be present in the scrap, nor their level of activity, nor their physical form, are known. In practice abnormal radioactivity in scrap is detected by comparison with ambient radioactivity. However, ambient radioactivity cannot be regarded as a threshold of acceptability which applies to all products . Its level varies substantially from one place to another. All products display natural radioactivity: its level varies greatly, but in some cases it significantly supplements ambient radioactivity, though this does not mean that the products must be considered dangerous (the classic example is that of some granites and some refractory materials). In our arrival checks on scrap-carrying vehicles (lorries and wagons) using gantries, we focus on changes in the measured ambient radioactivity, expressed in impulses per second, which arise from the presence of the vehicle between the sensor and the ambient radioactivity. For each vehicle, this shielding effect is expressed in terms of the ratio between the level measured in the presence of the vehicle and the level measured immediately before its arrival. The result is therefore a dimensionless number. We carried out a statistical analysis of the results of lorry checks at three sites where the checking equipment is identical, but the natural ambient radioactivity levels very different. We observed that the distributions of the values of this ratio were identical for all the sites, and relate very well to a Gaussian distribution with a mean value of 0.71 and a standard deviation of 0.06. Hence these values are characteristic of the dispersion of the shielding effect of the population of 'scrap-carrying lorries checked with a specific type of checking equipment

Recovering heavy rare earth metals from magnet scrap

Science.gov (United States)

Ott, Ryan T.; McCallum, Ralph W.; Jones, Lawrence L.

2017-08-08

A method of treating rare earth metal-bearing permanent magnet scrap, waste or other material in a manner to recover the heavy rare earth metal content separately from the light rare earth metal content. The heavy rare earth metal content can be recovered either as a heavy rare earth metal-enriched iron based alloy or as a heavy rare earth metal based alloy.

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)

Innovative technologies for recycling contaminated concrete and scrap metal

International Nuclear Information System (INIS)

Bossart, S.J.; Moore, J.

1993-01-01

Decontamination and decommissioning of US DOE's surplus facilities will generate enormous quantities of concrete and scrap metal. A solicitation was issued, seeking innovative technologies for recycling and reusing these materials. Eight proposals were selected for award. If successfully developed, these technologies will enable DOE to clean its facilities by 2019

Bioactive Glass Nanopowder for theTreatment of Oral Bone Defects

Directory of Open Access Journals (Sweden)

MH. Fathi

2007-09-01

Full Text Available Objective: Osseous defects around dental implants are often seen when implants are placed in areas with inadequate alveolar bone, or around failing implants. Bone regenera-tion in these areas using bone grafts or its substitutes may improve dental implants prog-nosis. The aim of this study was to prepare and characterize the bioactive glass nanopow-der and development of its coating for treatment of oral bone defects.Materials and Methods: Bioactive bioglass coating was made on stainless steel plates by sol-gel technique. The powder shape and size was evaluated by transmission electron mi-cropscopy, and thermal properties studied using differential thermal analysis (DTA. Structural characterization techniques (XRD were used to analyze and study the structure and phase present in the prepared bioactive glass nanopowder. This nanopowder was immersed in the simulated body fluid (SBF solution. Fourier transform infrared spec-troscopy (FTIR was utilized to recognize and confirm the formation of apatite layer on prepared bioactive glass nanopowder.Results: The bioglass powder size was less than 100 nanometers which was necessary for better bioactivity, and preparing a homogeneous coating. The formation of apatite layer confirmed the bioactivity of the bioglass nanopowder. Crack-free and homogeneous bioglass coatings were achieved with no observable defects.Conclusion: It was concluded that the prepared bioactive glass nanopowder could be more effective as a bone replacement material than conventional bioactive glass to pro-mote bone formation in osseous defects. The prepared bioactive glass nanopowder could be more useful for treatment of oral bone defects compare to conventional hydroxyapatite or bioactive glass.

Processing and characterization of new oxysulfide glasses in the Ge-Ga-As-S-O system

International Nuclear Information System (INIS)

Maurel, C.; Petit, L.; Dussauze, M.; Kamitsos, E.I.; Couzi, M.; Cardinal, T.; Miller, A.C.; Jain, H.; Richardson, K.

2008-01-01

New oxysulfide glasses have been prepared in the Ge-Ga-As system employing a two-step melting process which involves the processing of the chalcogenide glass (ChG) and its subsequent melting with amorphous GeO 2 powder. Optical characterization of the synthesized oxysulfide glasses has shown that the cut-off wavelength decreases with increasing oxygen content, and this has been correlated to results of Raman and infrared (IR) spectroscopies which show the formation of new oxysulfide structural units. X-ray photoelectron spectroscopy (XPS) analysis to probe the bonding environment of oxygen atoms in the oxysulfide glass network, has revealed the preferred formation of Ga-O and Ge-O bonds in comparison to As-O bonds. This work has demonstrated that melting a ChG glass with GeO 2 leads to the formation of new oxysulfide glassy materials. - Graphical abstract: In this paper, we explain how new oxysulfide glasses are prepared in the Ge-Ga-As system employing a two-step process: (1) the processing of the chalcogenide glass (ChG) and (2) the re-melting of the ChG with GeO 2 powder. Raman, infrared and XPS spectroscopies show the formation of new oxysulfide structural units

The characterization of ceramic alumina prepared by using additive glass beads

Science.gov (United States)

Suprapedi; Muljadi; Sardjono, Priyo

2018-01-01

The ceramic alumina has been made by using additive glass bead (5 and 10 % wt.). There are two kinds of materials, such as : gamma Alumina and glass bead. Synthesis of alumina was done by ball milling for 24 hours, then the mixed powder was dried in drying oven at 100 °C for 6 hours. Furthermore, the dried powder was mixed by using 2 % of PVA and continued with compacted to form a pellet with pressure of 50 MPA. The next step is sintering process with variation temperature of 1150, 1200, 1250, 1300 and 1400 °C and holding time for 2 hours. The characterization conducted are consist of test density, hardness, shrinkage, and microstructure. The results show that ceramic alumina with addition of 10 % wt. glass bead has the higher value of density, hardness and shrinkage than addition of 5% wt. glass bead. The highest characterization of ceramic alumina with addition 10 % glass bead was achieved at sintering temperature of 1400 °C with density 3.68 g/cm3, hardness vickers 780.40 Hv and shrinkage 15.23 %. The XRD results show that it was founds a corrundum (alpha Alumina) as dominant phase and mullite as minor phase.

Multifunctionality in epoxy/glass fibers composites with graphene interphase

OpenAIRE

Mahmood, Haroon

2017-01-01

In this project, the synergetic effect of a graphene interphase in epoxy/glass fibers composites was investigated by coating glass fibers (GF) with graphene oxide (GO) and reduced graphene oxide (rGO) nanosheets by an electrophoretic deposition (EPD) technique. Graphite oxide was prepared using modified Hummers method in which raw graphite powder was oxidized using potassium permanganate (KMnO4) in acidic solution. Using ultrasonic technique, the graphite oxide was dispersed homogenously in w...

Glass formulation development and offgas analysis of microwave melter powder samples

International Nuclear Information System (INIS)

Semones, G.B.; Hoffman, C.R.; Phillips, J.A.

1994-04-01

Production of nuclear materials for defense applications has resulted in the accumulation of vast amounts of nuclear waste. This contaminated waste is in a variety of forms that require subsequent reprocessing to isolate and encapsulate the nuclear (e.g., uranium, plutonium, strontium, cesium, and americium) and toxic (e.g., lead, chromium, and cadmium) constituents. The encapsulating material must possess good chemical and mechanical durability to resist leaching of the nuclear and toxic constituents into the environment during permanent storage at a waste repository. Glass is an ideal encapsulating material because its open structure allows the introduction of different waste forms and the final vitreous product possesses a high degree of chemical stability. Microwave heating and melting is a relatively new advancement in glass processing which uses microwave radiation to heat the glass formers to adequate temperatures for sintering or melting. An advantage to this technique is that it enables more rapid heating than traditional heating mechanisms. This decrease in cycle time may help to limit exposure to workers encapsulating radioactive and/or toxic waste

Problems with radioactivity scrap in the iron and steel industry of the Czech and Slovak Republics

International Nuclear Information System (INIS)

Raab, J.; Toman, V.

1999-01-01

During the recent restructuring process, the Czech steel industry has undergone a drastic reduction in the steel production by around 40%. Under such situation, previously exported volumes have been diverted into domestic markets. For the export, the Czech steel industry had to make its efforts in enhancing the quality of products and in improving the technologies in accordance with ISO standards (ISO 9000 and also ISO 14000). Among the various new quality demands in the export market, the radioactive contamination of steel products has received a very high attention. The Czech Iron and Steel Federation has organized a working team specialized in solving the problems arising from radioactive contaminated metallurgical scrap and steel products. The working team is made up of specialists from steel producers and scrap handling firms of the Czech Republic and the Slovak Republic, of experts from the State Office for Nuclear Safety, the Ministry of Industry and Trade and the Metrological Institute. Members of the Inspectorate for Ionizing Radiation and the General Directory for Customs are also included. This working team takes part in the elaboration of the legislative norms in that area. This paper deals with all the detailed functions of the working team. At present, all the major Czech steel producers have installed stationary radiation monitoring systems for detecting the possible radioactivity in all materials entering into factories. Under an agreement arranged between the producers of the Czech Iron and Steel Federation, the tolerable range of radionuclide contents in steel scrap and steel products has been set at the maximum of 100 Bq/kg in ( scrap and steel products. In this respect, the large firms collecting and treating scrap have also installed stationary radiation monitoring systems. In such monitoring systems, the detector will measure and check the values of radioactivity above 10 - 15% higher than the natural background level. In the case that

Soil and groundwater contamination with heavy metals at two scrap iron and metal recycling facilities

DEFF Research Database (Denmark)

Jensen, Dorthe Lærke; Holm, P. E.; Christensen, Thomas Højlund

2000-01-01

Field studies were performed at two actual scrap iron and metal recycling facilities in order to evaluate the extent of heavy metal migration into subsoil and groundwater caused by more than 25 years of handling scrap directly on the ground without any measures to prevent leaching. Surface soil...... samples, called `scrap dirt', representing the different activities on the two recycling facilities, all showed very high concentrations of lead (Pb), copper (Cu) and zinc (Zn), high concentrations of cadmium (Cd) , chromium (Cr) and nickel (Ni) and somewhat elevated concentrations of many other metals....... In particular high concentrations were found for Pb at the car-battery salvage locations (13 to 26 g Pb kg±1) and Cu at the cable burning location (22 g Cu kg±1) at one site. The migration of metals below the surface in general (except at the car-battery salvage locations) was very limited even after...

Commercial alkaline earth boroaluminosilicate glasses for sealing solid oxide cell stacks. Part I: Development of glass-ceramic microstructure and thermomechanical properties

DEFF Research Database (Denmark)

Agersted, Karsten; Balic-Zunic, Tonci

2018-01-01

Sealing performance in solid oxide cell (SOC) stacks and the devitrification process of commercially available alkaline earth boroaluminosilicate glasses containing 48‐61 mol% SiO2, 18‐28 mol% CaO, 1‐7 mol% MgO, 7‐10 mol% Al2O3, 1‐11 mol% B2O3 plus minor amounts of Na2O, K2O, FeO, and TiO2 were...... investigated and quantified through analysis of phase assemblages as function of heat treatments above the glass transition temperatures using the electron microprobe and powder X‐ray diffraction. For two of these glasses devitrification behavior was compared to the devitrification behavior of similar glasses...... produced in the laboratory. Glasses were characterized after annealing in air at 800°C and 850°C for up to 6 weeks. Even though the glasses lie within a relatively narrow compositional range, sealing performance and the resulting microstructures differed significantly. Best thermomechanical properties...

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Science.gov (United States)

Sushama, D.

2014-10-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er2O3 doped TeO2-WO3-La2O3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING

Directory of Open Access Journals (Sweden)

Mônica Marques Caetano de Lima

2013-06-01

Full Text Available Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat these scraps to remove zinc layer using a thermal treatment process. The samples were fed to a rotative furnace in an inert ambient. It was tested the hot dip galvanized and eletrogalvanized scraps, varying the zinc coating weight between 20g/m2 and 150g/m2, temperature between 700°C and 900°C and time between 3 minutes and 10 minutes. Considering these conditions, it is verified that more than 70% of the zinc layer is removed at 700°C, in 10 minutes. Dust captured is about 60% of metallic zinc and 40% as zinc oxide. Based on these results, the recycling of BOF sludge can be feasible to the ironmaking process.

Optimization of fuel recovery through the stepwise co-pyrolysis of palm shell and scrap tire

International Nuclear Information System (INIS)

Abnisa, Faisal; Wan Daud, Wan Mohd Ashri

2015-01-01

Highlights: • The co-pyrolysis of palm shell and scrap tire was studied. • The effect of stepwise co-pyrolysis temperature was investigated. • Co-pyrolysis successfully improved the quantity and quality of product yields. • Stepwise co-pyrolysis slightly increased oil and gas, and decreased char. • The co-pyrolysis of 50% biomass and 50% scrap tire is recommended. - Abstract: This study optimized the use of biomass waste to generate fuel through co-pyrolysis. In this paper, the effects of stepwise co-pyrolysis temperature and different ratios between palm shells and scrap tires in feedstock were studied to observe any improvements in the quantity and quality of the liquid yield and its byproduct. The ratio of palm shells and scrap tires varied at 100:0, 75:25, 50:50, 25:75, and 0:100. The experiment was conducted in a fixed-bed reactor. The study was divided into two scenarios. The first scenario was performed at the optimum temperature of 500 °C with a reaction time of 60 min. In the second scenario, the temperature was set at 500 °C for 60 min before the temperature was increased to 800 °C with a high heating rate. After the temperature reached 800 °C, the condition was maintained for approximately 45 min. Results showed that an increase in the liquid and gas yields was achieved when the temperature increased after optimum conditions. Increased yield was also obtained when the proportion of scrap tire was increased in the feedstock. Several other important findings are discussed in this paper, including the phases of pyrolysis oil, features of the liquid product, and characteristics of the byproducts. All products from both scenarios were analyzed by various methods to understand their fuel characteristics

Bioleaching of metals from electronic scrap by moderately thermophilic acidophilic bacteria

NARCIS (Netherlands)

Ilyas, Sadia; Anwar, Munir A.; Niazi, Shahida B.; Ghauri, M. Afzal

The present work was aimed at studying the bioleachability of metals from electronic scrap by the selected moderately thermophilic strains of acidophilic chemolithotrophic and acidophilic heterotrophic bacteria. These included Sulfobacillus thermosulfidooxidans and an unidentified acidophilic

Phosphate glass fibre scaffolds: Tailoring of the properties and enhancement of the bioactivity through mesoporous glass particles.

Science.gov (United States)

Novajra, G; Boetti, N G; Lousteau, J; Fiorilli, S; Milanese, D; Vitale-Brovarone, C

2016-10-01

Novel bone glass fibre scaffolds were developed by thermally bonding phosphate glass fibres belonging to the P2O5-CaO-Na2O-SiO2-MgO-K2O-TiO2 system (TiPS2.5 glass). Scaffolds with fibres of 85 or 110μm diameter were fabricated, showing compressive strength in the range of 2-3.5MPa, comparable to that of the trabecular bone. The effect of different thermal treatments and fibre diameters and length on the final scaffold structure was investigated by means of micro-CT analysis. The change of the sintering time from 30 to 60min led to a decrease in the scaffold overall porosity from 58 to 21vol.% for the 85μm fibre scaffold and from 50 to 40vol.% when increasing the sintering temperature from 490 to 500°C for the 110μm fibre scaffold. The 85μm fibres resulted in an increase of the scaffold overall porosity, increased pore size and lower trabecular thickness; the use of different fibre diameters allowed the fabrication of a scaffold showing a porosity gradient. In order to impart bioactive properties to the scaffold, for the first time in the literature the introduction in these fibre scaffolds of a bioactive phase, a melt-derived bioactive glass (CEL2) powder or spray-dried mesoporous bioactive glass particles (SD-MBG) was investigated. The scaffold bioactivity was assessed through soaking in simulated body fluid. CEL2/glass fibre scaffold did not show promising results due to particle detachment from the fibres during soaking in simulated body fluid. Instead the use of mesoporous bioactive powders showed to be an effective way to impart bioactivity to the scaffold and could be further exploited in the future through the ability of mesoporous particles to act as systems for the controlled release of drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

29 CFR 570.63 - Occupations involved in the operation of paper-products machines, scrap paper balers, and paper...

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Occupations involved in the operation of paper-products machines, scrap paper balers, and paper box compactors (Order 12). 570.63 Section 570.63 Labor Regulations... involved in the operation of paper-products machines, scrap paper balers, and paper box compactors (Order...

Lithium Carbonate Recovery from Cathode Scrap of Spent Lithium-Ion Battery: A Closed-Loop Process.

Science.gov (United States)

Gao, Wenfang; Zhang, Xihua; Zheng, Xiaohong; Lin, Xiao; Cao, Hongbin; Zhang, Yi; Sun, Zhi

2017-02-07

A closed-loop process to recover lithium carbonate from cathode scrap of lithium-ion battery (LIB) is developed. Lithium could be selectively leached into solution using formic acid while aluminum remained as the metallic form, and most of the other metals from the cathode scrap could be precipitated out. This phenomenon clearly demonstrates that formic acid can be used for lithium recovery from cathode scrap, as both leaching and separation reagent. By investigating the effects of different parameters including temperature, formic acid concentration, H 2 O 2 amount, and solid to liquid ratio, the leaching rate of Li can reach 99.93% with minor Al loss into the solution. Subsequently, the leaching kinetics was evaluated and the controlling step as well as the apparent activation energy could be determined. After further separation of the remaining Ni, Co, and Mn from the leachate, Li 2 CO 3 with the purity of 99.90% could be obtained. The final solution after lithium carbonate extraction can be further processed for sodium formate preparation, and Ni, Co, and Mn precipitates are ready for precursor preparation for cathode materials. As a result, the global recovery rates of Al, Li, Ni, Co, and Mn in this process were found to be 95.46%, 98.22%, 99.96%, 99.96%, and 99.95% respectively, achieving effective resources recycling from cathode scrap of spent LIB.

Research on Zr50Al15-xNi10Cu25Yx amorphous alloys prepared by mechanical alloying with commercial pure element powders

International Nuclear Information System (INIS)

Long Woyun; Ouyang Xueqiong; Luo Zhiwei; Li Jing; Lu Anxian

2011-01-01

Amorphous Zr 50 Al 15-x Ni 10 Cu 25 Y x alloy powders were fabricated by mechanical alloying at low vacuum with commercial pure element powders. The effects on glass forming ability of Al partial substituted by Y in Zr 50 Al 15 Ni 10 Cu 25 and thermal stability of Si 3 N 4 powders addition were investigated. The as-milled powders were characterized by X-ray diffraction, scanning electron microscopy and differential scanning calorimeter. The results show that partial substitution of Al can improve the glass forming ability of Zr 50 Al 15 Ni 10 Cu 25 alloy. Minor Si 3 N 4 additions raise the crystallization activation energy of the amorphous phase and thus improve its thermal stability. -- Research Highlights: → ZrAlNiCu amorphous alloys can be synthesized by MA in low cost. → Appropriate amount of Al substituted by Y in ZrAlNiCu alloy can improve its glass forming ability. → A second phase particle addition helps to improve the thermal stability of the amorphous matrix.

Incident involving radioactive material in steel scrap

International Nuclear Information System (INIS)

Drabova, D.; Matzner, J.; Prouza, Z.

1998-01-01

In early March of 1996, a wagon with steel scrap heading from the Czech Republic to Italy was returned as a strongly contaminated material. Based on the integral dose (dose rate 650 mGy/h in front of the wagon) and spectrometric measurement and evaluation, it was concluded that an unshielded cobalt-60 source (1.6 TBq) was present. The history of the event (notification, assessment, intervention planning, intervention) is highlighted and the lesson learned from the incident is discussed. (P.A.)

Low sintering temperature glass waste forms for sequestering radioactive iodine

Science.gov (United States)

Nenoff, Tina M.; Krumhansl, James L.; Garino, Terry J.; Ockwig, Nathan W.

2012-09-11

Materials and methods of making low-sintering-temperature glass waste forms that sequester radioactive iodine in a strong and durable structure. First, the iodine is captured by an adsorbant, which forms an iodine-loaded material, e.g., AgI, AgI-zeolite, AgI-mordenite, Ag-silica aerogel, ZnI.sub.2, CuI, or Bi.sub.5O.sub.7I. Next, particles of the iodine-loaded material are mixed with powdered frits of low-sintering-temperature glasses (comprising various oxides of Si, B, Bi, Pb, and Zn), and then sintered at a relatively low temperature, ranging from 425.degree. C. to 550.degree. C. The sintering converts the mixed powders into a solid block of a glassy waste form, having low iodine leaching rates. The vitrified glassy waste form can contain as much as 60 wt % AgI. A preferred glass, having a sintering temperature of 500.degree. C. (below the silver iodide sublimation temperature of 500.degree. C.) was identified that contains oxides of boron, bismuth, and zinc, while containing essentially no lead or silicon.

Evaluation of copper for divider subassembly in MCO Mark IA and Mark IV scrap fuel baskets

International Nuclear Information System (INIS)

Graves, C.E.

1997-01-01

The K Basin Spent Nuclear Fuel (SNF) Project Multi-Canister Overpack (MCO) subprojection eludes the design and fabrication of a canister that will be used to confine, contain, and maintain fuel in a critically safe array to enable its removal from the K Basins, vacuum drying, transport, staging, hot conditioning, and interim storage (Goldinann 1997). Each MCO consists of a shell, shield plug, fuel baskets (Mark IA or Mark IV), and other incidental equipment. The Mark IA intact and scrap fuel baskets are a safety class item for criticality control and components necessary for criticality control will be constructed from 304L stainless steel. It is proposed that a copper divider subassembly be used in both Mark IA and Mark IV scrap baskets to increase the safety basis margin during cold vacuum drying. The use of copper would increase the heat conducted away from hot areas in the baskets out to the wall of the MCO by both radiative and conductive heat transfer means. Thus copper subassembly will likely be a safety significant component of the scrap fuel baskets. This report examines the structural, cost and corrosion consequences associated with using a copper subassembly in the stainless steel MCO scrap fuel baskets

Pyrolysis of a waste from the grinding of scrap tyres.

Science.gov (United States)

Fernández, A M; Barriocanal, C; Alvarez, R

2012-02-15

The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900°C) in a horizontal oven. The three products - gas, oil and char - obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N(2) adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber. Copyright © 2011 Elsevier B.V. All rights reserved.

Recycling method of rubbish glass, wasted slate and oyster shell; Gan Ca haizai wo riyosuru kenzaiyo glass kuzu oyobi senshoseki kuzu no recycle

Energy Technology Data Exchange (ETDEWEB)

Okawa, A.; Omi, M. [Tohoku University, Sendai (Japan). Institute for Advanced Materials Processing

1996-03-29

Examination was made about the method of recycling rubbish glass and Gensho-stone slate, left after the use of construction materials, and oyster shells. In the experiment, quartz powder having the highest softening temperature was used instead of rubbish glass powder, and H3PO4 was used as the additive agent. The Gensho-stone slate was ground in a ball mill into power smaller than 100 mesh. The main constituent of the oyster shell, CaCO3, was subjected to thermolysis for conversion into CaO; and calcium phosphate was used as animal bone powder. The above-said materials as the starting materials were subjected to pressure-forming, and heating was done in the air at 1173K for 7.2ks for the production of sintered pellets. The sintered bodies were left in the air for 30 days and examined for geometrical changes, and it was found that the Gensho-stone slate was the best specimen, with the oyster shell occupying the second place, and that the sintered bodies of bone powder and SiO2 absorbed moisture indicating they were short of serviceability. As for the use of sintered bodies, Gensho stone may be used as material for landscape building while CaO may be used as a Ca ion source in the sea for cultivating seashells. 5 refs., 5 figs., 3 tabs.

An assessment on the recycling opportunities of wastes emanating from scrap metal processing in Mauritius

Energy Technology Data Exchange (ETDEWEB)

Mauthoor, Sumayya, E-mail: sumayya.mauthoor@umail.uom.ac.mu [Department of Chemical and Environmental Engineering, University of Mauritius, Réduit (Mauritius); Mohee, Romeela [Professor of Chemical and Environmental Engineering, National Research Chair in Solid Waste Management, Mauritius Research Council (Mauritius); Kowlesser, Prakash [Solid Waste/Beach Management Unit, Ministry of Local Government and Outer Islands (Mauritius)

2014-10-15

Highlights: • Scrap metal processing wastes. • Areas of applications for slag, electric arc furnace dust, mill scale and wastewater sludge. • Waste generation factor of 349.3 kg per ton of steel produced. • Waste management model. - Abstract: This paper presents an assessment on the wastes namely slag, dust, mill scale and sludge resulting from scrap metal processing. The aim of this study is to demonstrate that there are various ways via which scrap metal processing wastes can be reused or recycled in other applications instead of simply diverting them to the landfill. These wastes are briefly described and an overview on the different areas of applications is presented. Based on the results obtained, the waste generation factor developed was 349.3 kg per ton of steel produced and it was reported that slag represents 72% of the total wastes emanating from the iron and steel industry in Mauritius. Finally the suitability of the different treatment and valorisation options in the context of Mauritius is examined.

Effects of hydrolysis on solid-state relaxation and stickiness behavior of sodium caseinate-lactose powders.

Science.gov (United States)

Mounsey, J S; Hogan, S A; Murray, B A; O'Callaghan, D J

2012-05-01

Hydrolyzed or nonhydrolyzed sodium caseinate-lactose dispersions were spray dried, at a protein: lactose ratio of 0.5, to examine the effects of protein hydrolysis on relaxation behavior and stickiness of model powders. Sodium caseinate (NC) used included a nonhydrolyzed control (DH 0) and 2 hydrolyzed variants (DH 8.3 and DH 15), where DH = degree of hydrolysis (%). Prior to spray drying, apparent viscosities of liquid feeds (at 70°C) at a shear rate of 20/s were 37.6, 3.14, and 3.19 mPa·s, respectively, for DH 0, DH 8, and DH 15 dispersions. Powders containing hydrolyzed casein were more susceptible to sticking than those containing intact NC. The former had also lower bulk densities and powder particle sizes. Scanning electron microscopy showed that hydrolyzed powders had thinner particle walls and were more friable than powders containing intact NC. Secondary structure of caseinates, determined by Fourier transform infrared spectroscopy, was affected by the relative humidity of storage and the presence of lactose as co-solvent rather than its physical state. Glass transition temperatures and lactose crystallization temperatures, determined by differential scanning calorimetry were not affected by caseinate hydrolysis, although the effects of protein hydrolysis on glass-rubber transitions (T(gr)) could be determined by thermo-mechanical analysis. Powders containing hydrolyzed NC had lower T(gr) values (~30°C) following storage at a higher subcrystallization relative humidity (33%) compared with powder with nonhydrolyzed NC (T(gr) value of ~40°C), an effect that reflects more extensive plasticization of powder matrices by moisture. Results support that sodium caseinate-lactose interactions were weak but that relaxation behavior, as determined by the susceptibility of powder to sticking, was affected by hydrolysis of sodium caseinate. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Recycling of contaminated scrap by melting 10 years of experience in Germany

International Nuclear Information System (INIS)

Hamm, M.; Kreh, R.; Quade, U.

2000-01-01

Recycling of slightly radioactively contaminated steel scrap from nuclear installations has been developed in Germany since the early 80's. 14,000 t of steel scrap were melted in the single purpose melting plant CARLA at Siempelkamp, Krefeld, up to now. As much material as possible is used for recycling to cast iron containers, shieldings or to replace iron ore in heavy concrete shieldings by iron granules. By this well developed recycling technique within the nuclear cycle radiation exposure of the general public could be avoided. Due to the max. achievable volume reduction, 80 % of final disposal volume have been saved so far. To manage the upcoming metallic waste from decommissioning of nuclear power plants, this recycling path will play an important role in the future. (authors)

Phase equilibrium of the system Ag-Fe-Nd, and Nd extraction from magnet scraps using molten silver

International Nuclear Information System (INIS)

Takeda, O.; Okabe, T.H.; Umetsu, Y.

2004-01-01

To develop a new recycling process, we examined the direct extraction of neodymium (Nd) metal from Nd-Fe-B magnet scraps using molten silver (Ag) as an extraction medium. Prior to the extraction experiment, the phase equilibrium of the system Ag-Fe-Nd was investigated to estimate the theoretical extraction limit. It was observed that the Fe/Nd 2 Fe 17 mixture equilibrates with the molten Ag-Nd alloy containing 50-52 mol% Nd (57-59 mass% Nd) at 1363 K. The experimental results were in good agreement with the thermodynamic calculation based on literature values. By reacting Nd-Fe-B magnet scraps with molten silver at 1273 K, more than 90% of the neodymium in the scrap was extracted, and an Ag-Nd alloy containing 40-50 mass% Nd was obtained. The neodymium in the Ag-Nd alloy was separated from silver as Nd 2 O 3 by oxidizing the obtained alloy in air. Although the wettability of Nd 2 O 3 with molten silver caused some difficulties in the separation of neodymium from silver, molten silver is shown to be an effective medium for neodymium extraction from magnet scrap

Leaching behaviour of different scrap materials at recovery and recycling companies: full-, pilot- and lab-scale investigation.

Science.gov (United States)

Blondeel, E; Chys, M; Depuydt, V; Folens, K; Du Laing, G; Verliefde, A; Van Hulle, S W H

2014-12-01

Scrap material recovery and recycling companies are confronted with waste water that has a highly fluctuating flow rate and composition. Common pollutants, such as COD, nutrients and suspended solids, potentially toxic metals, polyaromatic hydrocarbons and poly chlorinated biphenyls can exceed the discharge limits. An analysis of the leaching behaviour of different scrap materials and scrap yard sweepings was performed at full-scale, pilot-scale and lab-scale in order to find possible preventive solutions for this waste water problem. The results of these leaching tests (with concentrations that frequently exceeded the Flemish discharge limits) showed the importance of regular sweeping campaigns at the company, leak proof or covered storage of specific scrap materials and oil/water separation on particular leachates. The particulate versus dissolved fraction was also studied for the pollutants. For example, up to 98% of the polyaromatic hydrocarbons, poly chlorinated biphenyls and some metals were in the particulate form. This confirms the (potential) applicability of sedimentation and filtration techniques for the treatment of the majority of the leachates, and as such the rainwater run-off as a whole. Copyright © 2014 Elsevier Ltd. All rights reserved.

Welding of a powder metallurgy uranium alloy

International Nuclear Information System (INIS)

Holbert, R.K.; Doughty, M.W.; Alexander-Morrison, G.M.

1989-01-01

The interest at the Oak Ridge Y-12 Plant in powder metallurgy (P/M) uranium parts is due to the potential cost savings in the fabrication of the material, to achieving a more homogeneous product, and to the reduction of uranium scrap. The joining of P/M uranium-6 wt-% niobium (U-6Nb) alloys by the electron beam (EB) welding process results in weld porosity. Varying the EB welding parameters did not eliminate the porosity. Reducing the oxygen and nitrogen content in this P/M uranium material did minimize the weld porosity, but this step made the techniques of producing the material more difficult. Therefore, joining wrought and P/M U-6Nb rods with the inertia welding technique is considered. Since no gases will be evolved with the solid-state welding process and the weld area will be compacted, porosity should not be a problem in the inertia welding of uranium alloys. The welds that are evaluated are wrought-to-wrought, wrought-to-P/M, and P/M-to-P/M U-6Nb samples

Quartz crystal reinforced quartz glass by spark plasma sintering

International Nuclear Information System (INIS)

Torikai, D.; Barazani, B.; Ono, E.; Santos, M.F.M.; Suzuki, C.K.

2011-01-01

The Spark Plasma Sintering presents fast processing time when compared to conventional sintering techniques. This allows to control the grain growth during sintering as well as the diffusion rate of a multi-material compounds, and make possible obtainment of functionally graded materials and nanostructured compounds. Powders of high purity silica glass and crystalline silica were sintered in a SPS equipment at temperatures around 1350° C, i.e., above the softening temperature of silica glass and below the melting temperature of quartz crystal. As a result, glass ceramics with pure silica glass matrix reinforced with crystalline alpha-quartz grains were fabricated at almost any desired range of composition, as well as controlled size of the crystalline reinforcement. X-ray diffraction and density measurements showed the possibility to manufacture a well controlled density and crystallinity glass-ceramic materials. (author)

Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

Science.gov (United States)

Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

2015-12-01

In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

Application of the UNECE Recommendations on Monitoring and Response Procedures for Radioactive Scrap Metal: From Theory to Practice

Energy Technology Data Exchange (ETDEWEB)

Magold, M.; Mansourian-Stephenson, S., E-mail: stephanie.mansourian-stephenson@unece.org [United Nations Economic Council for Europe, Geneva (Switzerland)

2011-07-15

The work of the United Nations Economic Commission for Europe (UNECE) in addressing the issue of radioactive material appearing inadvertently in scrap metal is summarized. After hosting several meetings of national and international representatives of the scrap metal industry and radiation protection experts, the UNECE issued recommendations in 2006 on Monitoring and Response Procedures for Radioactive Scrap Metal. Since then, the UNECE has been exploring, with its Member States, the extent to which the Recommendations have been utilized - by means of a questionnaire. In this paper the results of the questionnaire are presented and, on the basis of the results of the questionnaire, conclusions are drawn and recommendations made for international action in this field for the future. (author)

Thermal conductivity model for powdered materials under vacuum based on experimental studies

Directory of Open Access Journals (Sweden)

N. Sakatani

2017-01-01

Full Text Available The thermal conductivity of powdered media is characteristically very low in vacuum, and is effectively dependent on many parameters of their constituent particles and packing structure. Understanding of the heat transfer mechanism within powder layers in vacuum and theoretical modeling of their thermal conductivity are of great importance for several scientific and engineering problems. In this paper, we report the results of systematic thermal conductivity measurements of powdered media of varied particle size, porosity, and temperature under vacuum using glass beads as a model material. Based on the obtained experimental data, we investigated the heat transfer mechanism in powdered media in detail, and constructed a new theoretical thermal conductivity model for the vacuum condition. This model enables an absolute thermal conductivity to be calculated for a powder with the input of a set of powder parameters including particle size, porosity, temperature, and compressional stress or gravity, and vice versa. Our model is expected to be a competent tool for several scientific and engineering fields of study related to powders, such as the thermal infrared observation of air-less planetary bodies, thermal evolution of planetesimals, and performance of thermal insulators and heat storage powders.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Energy Technology Data Exchange (ETDEWEB)

Sushama, D., E-mail: sushasukumar@gmail.com [Research Awardee, LAMP, Dept. of Physics, Nit, Calicut, India and Dept. of Physics, M.S.M. College, Kayamkulam, Kerala (India)

2014-10-15

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er{sub 2}O{sub 3} doped TeO{sub 2}‐WO{sub 3}‐La{sub 2}O{sub 3} Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

International Nuclear Information System (INIS)

Sushama, D.

2014-01-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er 2 O 3 doped TeO 2 ‐WO 3 ‐La 2 O 3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption

Radiation accident at Mayapuri scrap market, Delhi, 2010

International Nuclear Information System (INIS)

Dey, A. B.; Mohanan, S.; Damodaran, D.; Soneja, M.; Jain, N.; Mohan, A.; Vikram, N. K.; Sood, R.

2012-01-01

This article reports the accidental public radiation exposure in a scrap market in Delhi (India)), on March 2010. The source, a gamma unit containing Cobalt-60 pencils, was improperly disposed of by a research institution in violation of national regulations for radiation protection and safety of radioactive sources. The unit was sold off to unsuspecting scrap dealers who dismantled the equipment. This event subsequently caused the most severe radiation accident reported in India to date, resulting in seven radiation injuries and one death. The clinical course of five of the patients treated at the All India Inst. of Medical Sciences hospital, New Delhi, is summarised in this report. All five patients suffered from the haematological form of the acute radiation syndrome and local cutaneous radiation injury as well. While four patients exposed to doses between 0.6 and 2.8 Gy survived with intensive or supportive treatment, the patient with the highest exposure of 3.1 Gy died due to acute respiratory distress syndrome and multi-organ failure on Day 16 after hospitalisation. The incident highlights the current gaps in the knowledge, infrastructure and legislation in handling radioactive materials. Medical institutions need to formulate individualised triage and management guidelines to immediately respond to future public radiological accidents. (authors)

Recycling of rare earths from Hg-containing fluorescent lamp scraps by solid state chlorination

International Nuclear Information System (INIS)

Lorenz, Tom; Froehlich, Peter; Bertau, Martin; Golon, Katja

2015-01-01

Solid state chlorination with NH 4 Cl comprises a method for rare earth recycling apart from pyro- or hydrometallurgical strategies. The examined partially Hg-containing fluorescent lamp scraps are rich in rare earths like La, Ce, Tb and Gd, but especially in Y and Eu. By mixing with NH 4 Cl and heating up to NH 4 Cl decomposition temperature in a sublimation reactor, Y and Eu could be transferred selectively into their respective metal chlorides with high yields. The yield and selectivity depend on temperature and the ratio of NH 4 Cl to fluorescent lamp scraps, which were varied systematically.

Crystallization of Pd40CU30Ni10P20 bulk metallic glass with and without pressure

DEFF Research Database (Denmark)

Yang, B.; Jiang, Jianzhong; Zhuang, Yanxin

2007-01-01

The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD). The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high...

Development of an eco-friendly material recycling process for spent lead glass using a mechanochemical process and Na2EDTA reagent.

Science.gov (United States)

Sasai, Ryo; Kubo, Hisashi; Kamiya, Masahiro; Itoh, Hideaki

2008-06-01

To develop a novel nonheating method with lower energy consumption and higher efficiency for recovering both lead and SiO2 glass matrix from spent lead-glass powder, we attempted to treat the spent lead glass by the mechanochemical method using the metal chelate reagent, sodium ethylenediaminetetraacetate (Na2EDTA). As a result of the wet ball-milling treatment of spent lead-glass powder sealed in a polypropylene bottle with zirconia balls, Na2EDTA, and water at room temperature, we found that more than 99 mass % of lead contained in the spentlead-glass powder was extracted as a lead-EDTA species from the solid silica glass network matrix. This separation phenomenon was accelerated by the enlargement of the solid-liquid interface area due to ball-milling atomization and by the high stability constant of lead-EDTA. High extraction yield suggests that Pb-O-Pb bonds in lead glass are weakened or are broken down by the wet ball-milling treatment, i.e., the strong mechanical energy such as the potential and/ or friction energy provided by ball-milling may be high enough to elute lead ions from silica matrix. Moreover, we succeeded in recovering both lead ions as lead sulfate, which is the main compound of anglesite, and the EDTA as sodium-EDTA, which is reusable as the metal chelate reagent in wet chemical process using the ferric sulfate.

Determination of alpha dose rate profile at the HLW nuclear glass/water interface

Energy Technology Data Exchange (ETDEWEB)

Mougnaud, S., E-mail: sarah.mougnaud@cea.fr [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Tribet, M.; Rolland, S. [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France); Renault, J.-P. [CEA Saclay, NIMBE UMR 3685 CEA/CNRS, 91191 Gif-sur-Yvette cedex (France); Jégou, C. [CEA Marcoule, DEN/DTCD/SECM, BP 17171, 30207 Bagnols-sur-Cèze cedex (France)

2015-07-15

Highlights: • The nuclear glass/water interface is studied. • The way the energy of alpha particles is deposited is modeled using MCNPX code. • A model giving dose rate profiles at the interface using intrinsic data is proposed. • Bulk dose rate is a majoring estimation in alteration layer and in surrounding water. • Dose rate is high in small cracks; in larger ones irradiated volume is negligible. - Abstract: Alpha irradiation and radiolysis can affect the alteration behavior of High Level Waste (HLW) nuclear glasses. In this study, the way the energy of alpha particles, emitted by a typical HLW glass, is deposited in water at the glass/water interface is investigated, with the aim of better characterizing the dose deposition at the glass/water interface during water-induced leaching mechanisms. A simplified chemical composition was considered for the nuclear glass under study, wherein the dose rate is about 140 Gy/h. The MCNPX calculation code was used to calculate alpha dose rate and alpha particle flux profiles at the glass/water interface in different systems: a single glass grain in water, a glass powder in water and a water-filled ideal crack in a glass package. Dose rate decreases within glass and in water as distance to the center of the grain increases. A general model has been proposed to fit a dose rate profile in water and in glass from values for dose rate in glass bulk, alpha range in water and linear energy transfer considerations. The glass powder simulation showed that there was systematic overlapping of radiation fields for neighboring glass grains, but the water dose rate always remained lower than the bulk value. Finally, for typical ideal cracks in a glass matrix, an overlapping of irradiation fields was observed while the crack aperture was lower than twice the alpha range in water. This led to significant values for the alpha dose rate within the crack volume, as long as the aperture remained lower than 60 μm.

Caltrans use of scrap tires in asphalt rubber products: a comprehensive review

Directory of Open Access Journals (Sweden)

Haiping Zhou

2014-02-01

Full Text Available The California Department of Transportation (Caltrans has been using scrap tire rubber in asphalt pavements since the 1970s in chip seals and the 1980s in rubberized hot mix asphalt(RHMA. Both the wet (field blend and dry processes were used in early trials. Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility, a terminal blend wet process. Since the beginning of this century, Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound, cost effective, and environmentally friendly strategies for using scrap tire rubber in roadway applications. By the end of year 2010, approximately 31%of all hot mix asphalt (HMA placed by Caltrans was rubberized HMA, roughly 1.2 million tons. Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development. These included the construction of two full-scale field experiments, five warranty projects, and an accelerated pavement study using a heavy vehicle simulator. Additionally, terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis. This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products. Current practices and future outlook are also discussed.

The Spanish system for the radiological surveillance and control of scrap and the products resulting from its processing

International Nuclear Information System (INIS)

Gil, E.

2001-01-01

Despite the fact that the use of radiation technologies has always been subjected to strict controls in most countries, the presence of radioactive materials in scrap has been detected relatively often in recent years. This has led to the implementation of a series of international initiatives aimed at detecting and preventing illicit international trafficking with radioactive material, intentional or otherwise. The Spanish iron and steel industry is one of the most important industrial sectors in the country, and depends to a large extent on the importing of a significant proportion of the scrap its uses as raw material. Experience has shown that that countries that import large quantities of scrap should complement the aforementioned international initiatives with others of national scope, in order to reduce the risks arising from the presence of radioactive material in scrap. In this context, the Spanish radiological protection authorities, along with the business associations involved in the metal recovery and smelting industry, have established a national system for the radiological surveillance and control of scrap and of the products resulting from its processing. The system consists of a set of legal bases, the installation of specific radiological surveillance equipment and the enhancement of other general purpose equipment that existed prior to these initiatives, the development of radiological training and information plans for the professionals involved in the metal recovery and smelting sectors and improvement to the national radiological emergency response system. (author)

Crystallization in Y-Si-Al-O-N glasses

Energy Technology Data Exchange (ETDEWEB)

Leng-Ward, G; Lewis, M H

1985-05-01

The development of crystallization in oxynitride glasses has been characterized using transmission electron microscopy and scanning electron microscopy, X-ray (energy-dispersive) microanalysis, and powder X-ray diffraction techniques. A series of glasses was prepared while maintaining the ratio of yttrium-to-silicon-to-aluminium, but replacing oxygen with nitrogen up to the nitrogen solubility limit. On annealing at 1250 C, the oxide glass fully crystallized into yttrium disilicate (Y2Si2O7). Al2O3 and mullite (Al6Si2O13) while, with increasing nitrogen content, the disilicate phase was progressively replaced by yttrium aluminium garnet (Y3Al5O12) and nitrogen was mainly incorporated into Si2N2O. Annealing of the nitrogen glasses at 1100 C produced partial crystallization involving an intermediate phase related to nitrogen-wollastonite. Phase separation in an as-quenched SiO2-rich Y-Si-Al-O composition glass is illustrated. 9 references.

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

Scrap metals' role in circular economy in Ghana, using Sunyani as a ...

African Journals Online (AJOL)

EJIRO

quantity and economic value of scrap metals as essential part of resource ... Therefore, proper education, policy and regulatory measures are key recommendations to ... The methodology of this research includes the description of the.

Development of dense glass-ceramic from recycled soda-lime-silicate glass and fly ash for tiling

Science.gov (United States)

Mustaffar, Mohd Idham; Mahmud, Mohamad Haniza; Hassan, Mahadi Abu

2017-12-01

Dense glass-ceramics were prepared by sinter-crystallization process from a combination of soda-lime-silicate glass waste and fly ash. Bentonite clay that acted as a binder was also added in a prepared formulation. The powder mixture of soda-lime glass, fly ash and bentonite clay were compacted by using uniaxial hydraulic press machine and sintered at six (6) various temperatures namely 750, 800, 850, 900, 950 and 1000 °C. The heating rate and sintering time were set at 5 °C/min and 30 minutes respectively. The results revealed that modulus of rupture (MOR), density and linear shrinkage increase first from 750 to 800 °C but decrease later after 800 to 1000 °C. In the meantime, water absorption was showing completely an opposite trend. The glass-ceramic sintered at 800 °C was found to have the best combination of physical-mechanical properties and has the potential to be applied in the construction industry particularly as floor and wall tiles because of the simple manufacturing process at low temperature.

Kinetics of the Thermal Degradation of Granulated Scrap Tyres: a Model-free Analysis

Directory of Open Access Journals (Sweden)

Félix A. LÓPEZ

2013-12-01

Full Text Available Pyrolysis is a technology with a promising future in the recycling of scrap tyres. This paper determines the thermal decomposition behaviour and kinetics of granulated scrap tyres (GST by examining the thermogravimetric/derivative thermogravimetric (TGA/DTG data obtained during their pyrolysis in an inert atmosphere at different heating rates. The model-free methods of Friedman, Flynn-Wall-Ozawa and Coats-Redfern were used to determine the reaction kinetics from the DTG data. The apparent activation energy and pre-exponential factor for the degradation of GST were calculated. A comparison with the results obtained by other authors was made.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2947

The Effectof Underwater Explosion on the Kinetics of Alkaline Leaching of Roasted Tungsten Carbide Scraps for Recycling

OpenAIRE

BAIK, Seung Woo; SHIBAYAMA, Atsushi; MURATA, Kenji; FUJITA, Toyohisa

2004-01-01

Wasted tungsten scraps are important resources for recycling, however, the mechanical recycle process of tungsten has a difficulty for recycling due to its mechanical strength. Underwater explosion fracturing technique was designed for solving this problem. The kinetics for alkaline leaching of roasted tungsten alloy scraps with different size distribution prepared by two ways of crushing technique has been investigated to evaluate the effect of the underwater explosion-crushing. The merit of...

A novel approach to determine the thermal transition of gum powder/hydro-gels using dynamic mechanical analysis

Science.gov (United States)

Nagamadhu, M.; Jeyaraj, P.; Kumar, G. C. Mohan

2018-04-01

The dynamic characterization of materials plays a major role in the present area. The many researchers are worked on solid materials and its characterization, it can be tested using dynamic mechanical analyzer (DMA), however, no such work on powder a semiliquid samples. The powder and liquid samples can also easily characterization as like solid samples using DMA. These powder samples are analyzed with a material pocket method which can be used to accurately determine very low levels of variation in powder properties, due to the high sensitivity of DMA to glass transitions. No such DMA studies on hydrogel and Gum powders. The gum powders are used in various applications start from food industries, pharmacy, natural gums paste, biomedical applications etc. among all this applications gum Ghatti is one of the powders using for varies applications. Around 50 milligrams of Ghatti powders are placed inside material pocket and analyzed storage modulus (G'), loss modulus (G″) and tan delta (δ). Also, understand the curing and glass transition effect using water, glycerin and superplastic from room temperature to 200°C. The result shows that storage modulus decreases with increase in temperature in pure Ghatti powder. The surprising improvement in storage modulus was found with an increase in temperature with addition of water, glycerin, and superplastic. However, loss modulus and tan delta are also having very significant influence and also shows a clear peak of the tan delta. The loss modulus results were found to be improved by adding solidifying agents, along with this water and superplastic better influence. But glycerine found to be hydrogel in nature and thermodynamic properties are much influenced by frequency.

Scrap Tyre Management Pathways and Their Use as a Fuel—A Review

Directory of Open Access Journals (Sweden)

Amir Rowhani

2016-10-01

Full Text Available This article provides a review of different methods for managing waste tyres. Around 1.5 billion scrap tyres make their way into the environmental cycle each year, so there is an extreme demand to manage and mitigate the environmental impact which occurs from landfilling and burning. Numerous approaches are targeted to recycle and reuse the tyre rubber in various applications. Among them, one of the most important methods for sustainable environmental stewardship is converting tyre rubber components into bio-oil. In this study, scrap tyre management techniques including landfill, retreading, recycling, combustion, and conversion to liquid fuels was reviewed (including gasification, hydrothermal liquefaction, and pyrolysis. The effects of parameters such as reactor types, pyrolysis temperature, and catalyst on the oil, gas and solid products in pyrolysis process were investigated.

Hot isostatic pressing of glass-zeolite composites

International Nuclear Information System (INIS)

Hash, M.C.; Pereira, C.; Lewis, M.A.

1996-01-01

Glass-zeolite waste forms are being developed for immobilizing the chloride waste salt generated from the electrometallurgical treatment of spent fuel. Glass-zeolite composites with high densities were made using hot isostatic pressing (HIP) techniques. Processing parameters were investigated to yield desirable structural ceramic properties such as mechanical, chemical, and thermal stability. Limits for these parameters were determined by differential thermal and thermogravimetric analysis. The resulting ceramic properties such as bulk density, open or apparent porosity, and leach resistance were determined. In addition, phase equilibria and particle-size distribution were observed by optical light and electron microscopy. Pre-HIP processing techniques were also studied to ensure intimate mixing of the glass and zeolite powders. Particle size distributions resulting from dry blending procedure are appropriate for needed flow and packing characteristics

MoO{sub 3} incorporation in magnesium aluminosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

2015-03-15

Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO{sub 3}) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO{sub 3} can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO{sub 3} increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO{sub 4}{sup 2−} units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO{sub 4}.

Economic feasibility of radioactive scrap steel recycling

International Nuclear Information System (INIS)

Balhiser, R.; Rosholt, D.; Nichols, F.

1995-01-01

The goal of MSE's Radioactive Scrap Steel (RSS) Recycle Program is to develop practical methods for recycling RSS into useful product. This paper provides interim information about ongoing feasibility investigations that are scheduled for completion by September 1995. The project approach, major issues, and cost projections are outlined. Current information indicates that a cost effective RSS Recycling Facility can be designed, built, and in operation by 1999. The RSS team believes that high quality steel plate can be made from RSS at a conversion cost of $1500 per ton or less

Optimization of the contents of hollow glass microsphere and sodium hexametaphosphate for glass fiber vacuum insulation panel

Science.gov (United States)

Li, C. D.; Chen, Z. F.; Zhou, J. M.

2016-07-01

In this paper, various additive amounts of hollow glass microspheres (HGMs) and sodium hexametaphosphate (SHMP) powders were blended with flame attenuated glass wool (FAGW) to form hybrid core materials (HCMs) through the wet method. Among them, the SHMP was dissolved in the glass fiber suspension and coated on the surface of glass fibers while the HGMs were insoluble in the glass fiber suspension and filled in the fiber-fiber pores. The average pore diameter of the FAGW/HGM HCMs was 8-11 μm which was near the same as that of flame attenuated glass fiber mats (FAGMs, i.e., 10.5 µm). The tensile strength of the SHMP coated FAGMs was enhanced from 160 N/m to 370 N/m when SHMP content increased from 0 wt.% to 0.2 wt.%. By contrast, the tensile strength of the FAGW/HGM HCMs decreased from 160 N/m to 40 N/m when HGM content increased from 0 wt.% to 50 wt.%. Both the FAGW/HGM HCMs and SHMP coated FAGMs were vacuumed completely to form vacuum insulation panels (VIPs). The results showed that both the addition of SHMP and HGM led a slight increase in the thermal conductivity of the corresponding VIPs. To obtain a high-quality VIP, the optimal SHMP content and HGM content in glass fiber suspension was 0.12-0.2 wt.% and 0 wt.%.

Wastes from plutonium conversion and scrap recovery operations

Energy Technology Data Exchange (ETDEWEB)

Christensen, D.C.; Bowersox, D.F.; McKerley, B.J.; Nance, R.L.

1988-03-01

This report deals with the handling of defense-related wastes associated with plutonium processing. It first defines the different waste categories along with the techniques used to assess waste content. It then discusses the various treatment approaches used in recovering plutonium from scrap. Next, it addresses the various waste management approaches necessary to handle all wastes. Finally, there is a discussion of some future areas for processing with emphasis on waste reduction. 91 refs., 25 figs., 4 tabs.

Wastes from plutonium conversion and scrap recovery operations

International Nuclear Information System (INIS)

Christensen, D.C.; Bowersox, D.F.; McKerley, B.J.; Nance, R.L.

1988-03-01

This report deals with the handling of defense-related wastes associated with plutonium processing. It first defines the different waste categories along with the techniques used to assess waste content. It then discusses the various treatment approaches used in recovering plutonium from scrap. Next, it addresses the various waste management approaches necessary to handle all wastes. Finally, there is a discussion of some future areas for processing with emphasis on waste reduction. 91 refs., 25 figs., 4 tabs

CRITICAL ASPECTS IN SCRAPS OF COLD SMOKED SALMON PROCESSING

Directory of Open Access Journals (Sweden)

C. Bernardi

2011-01-01

Full Text Available The aim of the paper was to summarize the critical aspects in the processing of smoked salmon scraps as resulted from seven different lots of samples through microbiological and chemical-physical analysis. Results demonstrate that this product has very variable salt content, high microbial counts influencing the shelf-life, rancidity problems depending on the raw material and is heavily contaminated by Listeria monocytogenes.

Structure of the AZ91 alloy pressure castings fabricated of home scrap containing charge

Directory of Open Access Journals (Sweden)

Z. Konopka

2011-04-01

Full Text Available The influence of the AZ91 alloy home scrap addition to the metal charge on both the structure and the selected mechanical propertiesof pressure castings was examined in this article. Two heats were made using different components, the first with only pure AZ91 alloyingots in the charge, and the second containing 30 wt % of home scrap. The hot chamber 3 MN machine was used for casting. Thestructures of the castings and their Brinell hardness were examined for both cases. A strong refinement of crystals was observed in castings made with the contribution of the recycled material. Any significant differences in castings hardness were not observed.

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.

Mathematical Modeling and Algebraic Technique for Resolving a Single-Producer Multi-Retailer Integrated Inventory System with Scrap

OpenAIRE

Yuan-Shyi Peter Chiu; Chien-Hua Lee; Nong Pan; Singa Wang Chiu

2013-01-01

This study uses mathematical modeling along with an algebraic technique to resolve the production-distribution policy for a single-producer multi-retailer integrated inventory system with scrap in production. We assume that a product is manufactured through an imperfect production process where all nonconforming items will be picked up and scrapped in each production cycle. After the entire lot is quality assured, multiple shipments will be delivered synchronously to m different retailers in ...

Glass-ceramic coating material for the CO2 laser based sintering of thin films as caries and erosion protection.

Science.gov (United States)

Bilandžić, Marin Dean; Wollgarten, Susanne; Stollenwerk, Jochen; Poprawe, Reinhart; Esteves-Oliveira, Marcella; Fischer, Horst

2017-09-01

The established method of fissure-sealing using polymeric coating materials exhibits limitations on the long-term. Here, we present a novel technique with the potential to protect susceptible teeth against caries and erosion. We hypothesized that a tailored glass-ceramic material could be sprayed onto enamel-like substrates to create superior adhesion properties after sintering by a CO 2 laser beam. A powdered dental glass-ceramic material from the system SiO 2 -Na 2 O-K 2 O-CaO-Al 2 O 3 -MgO was adjusted with individual properties suitable for a spray coating process. The material was characterized using X-ray fluorescence analysis (XRF), heating microscopy, dilatometry, scanning electron microscopy (SEM), grain size analysis, biaxial flexural strength measurements, fourier transform infrared spectroscopy (FTIR), and gas pycnometry. Three different groups of samples (each n=10) where prepared: Group A, powder pressed glass-ceramic coating material; Group B, sintered hydroxyapatite specimens; and Group C, enamel specimens (prepared from bovine teeth). Group B and C where spray coated with glass-ceramic powder. All specimens were heat treated using a CO 2 laser beam process. Cross-sections of the laser-sintered specimens were analyzed using laser scanning microscopy (LSM), energy dispersive X-ray analysis (EDX), and SEM. The developed glass-ceramic material (grain size d50=13.1mm, coefficient of thermal expansion (CTE)=13.310 -6 /K) could be spray coated on all tested substrates (mean thickness=160μm). FTIR analysis confirmed an absorption of the laser energy up to 95%. The powdered glass-ceramic material was successfully densely sintered in all sample groups. The coating interface investigation by SEM and EDX proved atomic diffusion and adhesion of the glass-ceramic material to hydroxyapatite and to dental enamel. A glass-ceramic material with suitable absorption properties was successfully sprayed and laser-sintered in thin films on hydroxyapatite as well as on

Activities and Issues in Monitoring Scrap Metal Against Radioactive Sources

Energy Technology Data Exchange (ETDEWEB)

Chen, S.Y., E-mail: sychen@anl.gov [Argonne National Laboratory, Argonne, IL (United States)

2011-07-15

Over the past few decades, the global scrap metal industry has grown increasingly vigilant regarding radioactive contamination. Accidental melts of radioactive sources in some smelting facilities, in particular, have caused considerable damage and required recovery efforts costing tens of millions of dollars. In response, the industry has developed and deployed countermeasures. Increasingly expensive and sophisticated radiation monitoring devices have been implemented at key scrap entry points - ports and scrapyards. Recognition of the importance of such endeavors has led to a series of activities aimed at establishing organized and coordinated efforts among the interested parties. Recent concerns over the potential use of radioactive sources for radiological devices in terrorist acts have substantially heightened the need for national and international authorities to further control, intercept, and secure the sources that have escaped the regulatory domain. Enhanced collaboration by the government and industry could substantially improve the effectiveness of efforts at control; the 'Spanish Protocol' as developed by the Spanish metal industry and government regulators is a good example of such collaboration. (author)

Laser cladding of bioactive glass coatings.

Science.gov (United States)

Comesaña, R; Quintero, F; Lusquiños, F; Pascual, M J; Boutinguiza, M; Durán, A; Pou, J

2010-03-01

Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass were demonstrated to exhibit a gradual wetting angle-temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle-temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Preparation of glass-forming materials from granulated blast furnace slag

Science.gov (United States)

Alonso, M.; Sáinz, E.; Lopez, F. A.

1996-10-01

Glass precursor materials, to be used for the vitrification of hazardous wastes, have been prepared from blast furnace slag powder through a sol-gel route. The slag is initially reacted with a mixture of alcohol (ethanol or methanol) and mineral acid (HNO3 or H2SO4) to give a sol principally consisting of Si, Ca, Al, and Mg alkoxides. Gelation is carried out with variable amounts of either ammonia or water. The gelation rate can be made as fast as desired by adding excess hydrolizing agent or else by distilling the excess alcohol out of the alkoxide solution. The resulting gel is first dried at low temperature and ground. The powder thus obtained is then heat treated at several temperatures. The intermediate and final materials are characterized by thermal analysis, infrared (IR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and chemical analysis. From the results, the operating conditions yielding a variety of glass precursors differing in their composition are established. The method, in comparison with direct vitrification of slag, presents a number of advantages: (1) the glass precursor obtained devitrifies at higher temperatures; (2) it enables the adjustment, to a certain extent, of the chemical composition of the glass precursor; and (3) it permits recovering marketable materials at different stages of the process.

Crystallization of high-strength nano-scale leucite glass-ceramics.

Science.gov (United States)

Theocharopoulos, A; Chen, X; Wilson, R M; Hill, R; Cattell, M J

2013-11-01

Fine-grained, high strength, translucent leucite dental glass-ceramics are synthesized via controlled crystallization of finely milled glass powders. The objectives of this study were to utilize high speed planetary milling of an aluminosilicate glass for controlled surface crystallization of nano-scale leucite glass-ceramics and to test the biaxial flexural strength. An aluminosilicate glass was synthesized, attritor or planetary milled and heat-treated. Glasses and glass-ceramics were characterized using particle size analysis, X-ray diffraction and scanning electron microscopy. Experimental (fine and nanoscale) and commercial (Ceramco-3, IPS Empress Esthetic) leucite glass-ceramics were tested using the biaxial flexural strength (BFS) test. Gaussian and Weibull statistics were applied. Experimental planetary milled glass-ceramics showed an increased leucite crystal number and nano-scale median crystal sizes (0.048-0.055 μm(2)) as a result of glass particle size reduction and heat treatments. Experimental materials had significantly (p0.05) strength difference. All other groups' mean BFS and characteristic strengths were found to be significantly different (pglass-ceramics with high flexural strength. These materials may help to reduce problems associated with brittle fracture of all-ceramic restorations and give reduced enamel wear. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Use of limestone powder during incorporation of Pb-containing cathode ray tube waste in self-compacting concrete.

Science.gov (United States)

Sua-iam, Gritsada; Makul, Natt

2013-10-15

For several decades, cathode ray tubes (CRTs) were the primary display component of televisions and computers. The CRT glass envelope contains sufficient levels of lead oxide (PbO) to be considered hazardous, and there is a need for effective methods of permanently encapsulating this material during waste disposal. We examined the effect of adding limestone powder (LS) on the fresh and cured properties of self-compacting concrete (SCC) mixtures containing waste CRT glass. The SCC mixtures were prepared using Type 1 Portland cement at a constant cement content of 600 kg/m(3) and a water-to-cement ratio (w/c) of 0.38. CRT glass waste cullet was blended with river sand in proportions of 20 or 40% by weight. To suppress potential viscosity effects limestone powder was added at levels of 5, 10, or 15% by weight. The slump flow time, slump flow diameter, V-funnel flow time, Marsh cone flow time, and setting time of the fresh concrete were tested, as well as the compressive strength and ultrasonic pulse velocity of the hardened concrete. Addition of limestone powder improved the fresh and hardened properties. Pb leaching levels from the cured concrete were within US EPA allowable limits. Copyright © 2013 Elsevier Ltd. All rights reserved.

Leaching kinetics of cobalt from the scraps of spent aerospace magnetic materials.

Science.gov (United States)

Zhou, Xuejiao; Chen, Yongli; Yin, Jianguo; Xia, Wentang; Yuan, Xiaoli; Xiang, Xiaoyan

2018-06-01

Based on physicochemical properties of the scraps of spent aerospace magnetic materials, a roasting - magnetic separation followed by sulfuric acid leaching process was proposed to extract cobalt. Roasting was performed at 500 °C to remove organic impurity. Non-magnetic impurities were reduced by magnetic separation and then the raw material was sieved into desired particle sizes. Acid leaching was carried out to extract cobalt from the scraps and experimental parameters included agitation speed, particle size, initial concentration of sulfuric acid and temperature. Agitation speed higher than 300 r/min had a relatively small impact on the cobalt extraction. As the particle size reduced, the content of cobalt in the raw material decreases and the extraction of cobalt by acid leaching increased at first and decreased afterwards. Raising the initial concentration of sulfuric acid and temperature contributed to improve the cobalt extraction and the influence of temperature was more remarkable. SEM image revealed that the spent aerospace magnetic materials mainly existed in the sliced strip flake with a loose surface and porous structure. Under the experimental condition, the leaching rate of cobalt from the scraps in sulfuric acid solution could be expressed as ln(-ln(1 - α)) = lnk + nlnt. The apparent activation energy was found to be 38.33 kJ/mol and it was mainly controlled by the surface chemical reaction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Upconversion studies of Er3+/Yb3+ doped SrO.TiO2 borosilicate glass ceramic system

International Nuclear Information System (INIS)

Maheshwari, Aditya; Om Prakash; Kumar, Devendra; Rai, S.B.

2011-01-01

Upconversion behaviour has been studied in various matrices and fine powders of SrTiO 3 by previous workers. In present work, Er 3+ /Yb 3+ were doped in appropriate ratio in SrO.TiO 2 borosilicate glass ceramic system to study the upconversion phenomenon. Dielectric properties of this class of glass ceramic system have been extensively investigated by Thakur et al. It has been observed that both upconversion efficiency and dielectric constant increases with transformation of glass into glass ceramic. Therefore, present investigation is based upon the study of optical as well as the electrical properties of same glass ceramic system. In order to prepare different crystalline matrices, two different Er 3+ /Yb 3+ :SrO.TiO 2 borosilicate glasses with same amount of Er 2 O 3 and Yb 2 O 3 were prepared by melt quench method. Glasses were transparent with light-wine colour. Glass ceramics were prepared from the glasses by heat treatment based on DTA (Differential thermal analysis) results. Glass ceramics were fully opaque with brownish-cream colour. Powder X-ray diffraction (XRD) patterns confirmed that two different crystalline matrices, Sr 3 Ti 2 O 7 , Ti 10 O 19 and SrTiO 3 , TiO 2 were present in two glass ceramic samples respectively. Luminescence properties of glass and glass ceramic samples with 976nm laser irradiation showed that the intensities of the green and red emission increased multiple times in glass ceramic than that of the glass. Possible mechanisms responsible for upconversion eg. Energy Transfer (ET) and Excited State Absorption (ESA), were studied through laser pumping power log dependence

Lead scrap use and trade patterns in the United States, 1995-2012

Science.gov (United States)

Wilburn, David R.

2015-09-22

Since 1995, domestic production of lead has increasingly shifted from primary mining and smelting to the recovery of lead-bearing scrap by the secondary lead industry, which accounted for 91 percent of U.S. lead production in 2012. Increasingly stringent environmental regulations for lead emissions in the United States have contributed to the closure of primary lead refineries and the consolidation of the secondary lead industry. Domestic production of lead from the primary and secondary sectors in 2012 is essentially unchanged from the amount produced in 1995. The U.S. secondary industry produced an estimated 145,000 metric tons more refined lead in 2012 than it did in 1995, primarily by recovering lead from battery scrap, allowing the U.S. to maintain production at a level sufficient to supply much of the domestic demand for lead.

The prospect for recycle of radioactive scrap metals to products for restricted and unrestricted use

International Nuclear Information System (INIS)

Liby, A.L.

1995-01-01

Large quantities of radioactive scrap metals will arise from decontamination and decommissioning of nuclear power plants and DOE facilities. Much of this metal can be easily decontaminated and released to the existing secondary metals industry for recycling. For metal that can not be readily released, recycle into restricted-use end products is an economically attractive alternative to burial as low level radioactive waste. This paper will examine sources and types of scrap metal, technical approaches, potential products, and economics of metals recycle. Construction, licensing, environmental compliance, and possible reuse of existing nuclear facilities for metals recycling will be discussed. (author)

Reuse of waste water from high pressure water jet decontamination for reactor decommissioning scrap metal

International Nuclear Information System (INIS)

Deng Junxian; Li Xin; Hou Huijuan

2011-01-01

For recycle and reuse of reactor decommissioning scrap metal by high pressure water jet decontamination, large quantity of radioactive waste water will be generated. To save the cost of radioactive waste water treatment and to reduce the cost of the scrap decontamination, this part of radioactive waste water should be reused. Most of the radioactivities in the decontamination waste water come from the solid particle in the water. Thus to reuse the waste water, the solid particle in the waster should be removed. Different possible treatment technologies have been investigated. By cost benefit analysis the centrifugal separation technology is selected. (authors)

Study on Modified Water Glass Used in High Temperature Protective Glass Coating for Ti-6Al-4V Titanium Alloy

Directory of Open Access Journals (Sweden)

Shuang Yang

2018-04-01

Full Text Available Sodium silicate water glass was modified with sodium polyacrylate as the binder, the composite slurry used for high-temperature oxidation-resistant coating was prepared by mixing glass powder with good lubrication properties in the binder. The properties of the modified binder and high-temperature oxidation resistance of Ti-6Al-4V titanium alloy coated with composite glass coating were studied by XRD, SEM, EDS, TG-DSC and so on. Results showed that sodium polyacrylate modified water glass could obviously improve the suspension stability of the binder, the pyrolytic carbon in the binder at high temperature could increase the surface tension in the molten glass system, and the composite glass coating could be smooth and dense after heating. Pyrolytic carbon diffused and combined with oxygen in the coating under the heating process to protect the titanium alloy from oxidation. The thickness of the oxide layer was reduced 51% after applying the high-temperature oxidation-resistant coating. The coating also showed a nearly 30% reduction in friction coefficient due to the boundary lubricant regime. During cooling, the coating could be peeled off easily because of the mismatched CTE between the coating and substrate.

Characterization of Incorporation the Glass Waste in Adhesive Mortar

Science.gov (United States)

Santos, D. P.; Azevedo, A. R. G.; Hespanhol, R. L.; Alexandre, J.

Ehe search for reuse generated waste in urban centers, intending to preserve natural resources, has remained fairly constant, both in context of preventing exploitation of resources as the emplacement of waste on the environment. Glass waste glass created a serious environmental problem, mainly because of inconsistency of its flows. Ehe use of this product as a mineral additive, finely ground, cement replacement and aggregate is a promising direction for recycling. This work aims to study the influence of glass waste from cutting process in adhesive mortar, replacing part of cement. Ehe glass powder is used replacing Portland cement at 10, 15 and 20% by mass. Ehe produced mortars will be evaluated its performance in fresh and hardened states through tests performed in laboratory. Ehe selected feature is indicated by producers of additive and researchers to present good results when used as adhesive mortar.

PREPARATION AND CHARACTERIZATION OF POROUS WALLED HOLLOW GLASS MICROSPHERES

Energy Technology Data Exchange (ETDEWEB)

Raszewski, F; Erich Hansen, E; Ray Schumacher, R; David Peeler, D

2008-04-21

Porous-walled hollow glass microspheres (PWHGMs) of a modified alkali borosilicate composition have been successfully fabricated by combining the technology of producing hollow glass microspheres (HGMs) with the knowledge associated with porous glasses. HGMs are first formed by a powder glass--flame process, which are then transformed to PWHGMs by heat treatment and subsequent treatment in acid. Pore diameter and pore volume are most influenced by heat treatment temperature. Pore diameter is increased by a factor of 10 when samples are heat treated prior to acid leaching; 100 {angstrom} in non-heat treated samples to 1000 {angstrom} in samples heat treated at 600 C for 8 hours. As heat treatment time is increased from 8 hours to 24 hours there is a slight shift increase in pore diameter and little or no change in pore volume.

Liquid metal extraction of Nd from NdFeB magnet scrap

Energy Technology Data Exchange (ETDEWEB)

Xu, Yanchen [Iowa State Univ., Ames, IA (United States)

1999-12-10

This research involves using molten magnesium (Mg) to remove neodymium (Nd) from NdFeB magnet scrap by diffusion. The results show that liquid metal extraction of Nd may be a viable and inexpensive method for recovering the expensive rare earth element Nd for use in Mg castings.

Alteration of borosilicate glass under water saturated condition

International Nuclear Information System (INIS)

Tsukimura, K.; Matsuhisa, Y.; Kanai, Y.; Hirai, H.

1991-01-01

In the long term of the high-level nuclear waste disposal, the dissolving rates of radionuclides from the waste will be controlled by crystalline phases secondarily formed in the borosilicate glass by reaction with ground water. We have determined the crystalline phases formed from borosilicate glass in a hydrothermal experiment. Borosilicate glass powder (50 mg, Si 40 B 20 Al 4 Li 12 Na 14 K 3 Ca 2 Fe 5 O 140 ) and 200 ml of water were reacted at 300degC and 300 bars for 2 weeks with a cold-seal type hydrothermal high pressure apparatus. After the reaction the liquid phase was analyzed with atomic absorption spectroscopy and the solid phases with x-ray powder diffraction and analytical electron microscopy. The liquid phase contains 58 % of Na, 14 % of Li and 11 % of K but less than 1 % of Ca and Fe. The solid phases were found to be zeolite and smectite. The zeolite is isostructural with analcime Na 2 Al 2 (SiO 3 ) 4 · 2H 2 O or wairakite CaAl 2 (SiO 3 ) 4 · 2H 2 O and contains Ca and Si as major constituents but does not contain Al. Although no direct analytical evidence is available, logical induction of the experimental results indicates that the chemical composition of the zeolite is CaB 2 (SiO 3 ) 4 . The remaining x-ray powder diffraction peaks are same as those of smectite Na 06.7 (Al 3.33 Mg 0.67 )Si 8 O 20 (OH) 4 . However, since our starting material was free of Mg, and Na was not detected by AEM, the smectite may contain Fe instead of Mg, and Li instead of Na. (author)

Spray Drying of High Sugar Content Foods: Improving of Product Yield and Powder Properties

OpenAIRE

Mehmet Koç; Figen Kaymak-Ertekin

2016-01-01

Spray drying is the most preferred drying method to produce powdered food in the food industry and it is also widely used to convert sugar-rich liquid foods to a powder form. During and/or after spray drying process of sugar-rich products, undesirable situation was appeared such as stickiness, high moisture affinity (hygroscopicity) and low solubility due to low molecular weight monosaccharides that found naturally in the structure. The basis of these problems was formed by low glass transiti...

Potential of scrap tire rubber as lightweight aggregate in flowable fill.

Science.gov (United States)

Pierce, C E; Blackwell, M C

2003-01-01

Flowable fill is a self-leveling and self-compacting material that is rapidly gaining acceptance and application in construction, particularly in transportation and utility earthworks. When mixed with concrete sand, standard flowable fill produces a mass density ranging from 1.8 to 2.3 g/cm(3) (115-145 pcf). Scrap tires can be granulated to produce crumb rubber, which has a granular texture and ranges in size from very fine powder to coarse sand-sized particles. Due to its low specific gravity, crumb rubber can be considered a lightweight aggregate. This paper describes an experimental study on replacing sand with crumb rubber in flowable fill to produce a lightweight material. To assess the technical feasibility of using crumb rubber, the fluid- and hardened-state properties of nine flowable fill mixtures were measured. Mixture proportions were varied to investigate the effects of water-to-cement ratio and crumb rubber content on fill properties. Experimental results indicate that crumb rubber can be successfully used to produce a lightweight flowable fill (1.2-1.6 g/cm(3) [73-98 pcf]) with excavatable 28-day compressive strengths ranging from 269 to 1194 kPa (39-173 psi). Using a lightweight fill reduces the applied stress on underlying soils, thereby reducing the potential for bearing capacity failure and minimizing soil settlement. Based on these results, a crumb rubber-based flowable fill can be used in a substantial number of construction applications, such as bridge abutment fills, trench fills, and foundation support fills.

Development of novel strontium containing bioactive glass based calcium phosphate cement.

Science.gov (United States)

D'Onofrio, A; Kent, N W; Shahdad, S A; Hill, R G

2016-06-01

The aim of this study was to investigate the effect on properties of increasing strontium substitution for calcium in bioactive glasses used as precursors for novel calcium phosphate cements. Glasses were produced by progressively substituting strontium for calcium. Cements were prepared by mixing the glass powder with Ca(H2PO4)2 powder with a 2.5% solution of Na2HPO4. Setting times and compressive strength were measured after 1h, 1 day, 7 days and 28 days immersion in Tris buffer solution. X-ray diffraction (XRD), Fourier transform infrared spectroscopy and radiopacity were measured and crystal morphology was assessed using scanning electron microscopy. A correlation between the phases formed, morphology of the crystallites, setting time and compressive strength were analyzed. Setting time increased proportionally with strontium substitution in the glass up to 25%, whereas for higher substitutions it decreased. Compressive strength showed a maximum value of 12.5MPa and was strongly influenced by the interlocking of the crystals and their morphology. XRD showed that the presence of strontium influenced the crystal phases formed. Octacalcium phosphate (Ca8H2(PO4)6·5H2O, OCP) was the main phase present after 1h and 1 day whereas after 28 days OCP was completely transformed to strontium-containing hydroxyapatite (SrxCa(10-x)(PO4)6(OH)2, SrHA). Radiopacity increased proportionally to strontium substitution in the glass. A novel method to develop a bone substitute forming in vitro SrHA as a final product by using a bioactive glass as a precursor was shown. These novel injectable bioactive glass cements are promising materials for dental and orthopedic applications. Further in vivo characterizations are being conducted. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Development of a composite based on hydroxyapatite and magnesium and zinc‐containing sol–gel-derived bioactive glass for bone substitute applications

International Nuclear Information System (INIS)

Ashuri, Maziar; Moztarzadeh, Fathollah; Nezafati, Nader; Ansari Hamedani, Ali; Tahriri, Mohammadreza

2012-01-01

In the present study, a bioceramic-based composite was prepared by sintering compacts made up of mixtures of hydroxyapatite (HA) and sol–gel-derived bioactive glass (64SiO 2 -26CaO-5MgO-5ZnO) (based on mol%) powders. HA powder was mixed with different concentrations of the glass powders up to 30 wt.%. The effect of adding bioactive glass powder to HA matrix, on the mechanical properties of the composite was assessed by compression test. The specimen with the highest compressive strength was chosen to be immersed in simulated body fluid (SBF) to study apatite forming ability and dissolution behavior. It was found that compressive strength of the specimen was decreased 65% after maintaining in the SBF for 14 days. X-ray diffraction (XRD) showed prevalence of HA and β-TCP related peaks. Also, the surface morphology of the composite was observed using scanning electron microscopy (SEM). The study of degradation behavior revealed Si release capability of this composite. Biological evaluations in vitro confirmed the composite studied could induce osteoblast-like cells' activities. - Highlights: ► A novel composite based on HA/bioactive glass for bone substitutes was developed. ► Evaluations in vitro confirmed the composites induce bone-like cells' activities. ► A successful compromise of bioactivity and cytocompatibility was observed.

The slag from ELCOGAS IGCC thermal power plant as raw material for the synthesis of glass-ceramic materials. Part 2: Synthesis and characterization of the glass-ceramic materials

Energy Technology Data Exchange (ETDEWEB)

Aineto, M.; Acosta, A.; Rincon, J.M.A.; Romero, M. [University of Castilla La Mancha, Ciudad Real (Spain)

2006-01-15

There are here reported the result of the second phase of the investigation on the melting behavior of the slag and the process followed to synthesize glass-ceramic materials using this slag as raw component. Starting from a vitrifying mixture based on slag, glass cullet and precipitated calcium carbonate coming from sugar refining, we have obtained the parent glass named ECSCP, which exhibit a surface tendency of crystallization. Pressed specimens of 40 mm diameter and 7 mm height were conformed with the powdered ECSCP glass. The specimens were heat treated for crystalline phases development at temperatures between 800 and 1100{sup o}C during time intervals from 5 to 60 minutes. A series of wollastonite-anorthite-gehlenite glass-ceramics has been synthesized of different characteristics depending on the time and temperature of devitrification.

Alkali-free bioactive glasses for bone regeneration =

Science.gov (United States)

Kapoor, Saurabh

Bioactive glasses and glass-ceramics are a class of third generation biomaterials which elicit a special response on their surface when in contact with biological fluids, leading to strong bonding to living tissues. The purpose of the present study was to develop diopside based alkali-free bioactive glasses in order to achieve good sintering behaviour, high bioactivity, and a dissolution/ degradation rates compatible with the target applications in bone regeneration and tissue engineering. Another aim was to understand the structure-property relationships in the investigated bioactive glasses. In this quest, various glass compositions within the Diopside (CaMgSi2O6) - Fluorapatite (Ca5(PO4)3F) - Tricalcium phosphate (3CaO•P2O5) system have been investigated. All the glasses were prepared by melt-quenching technique and characterized by a wide array of complementary characterization techniques. The glass-ceramics were produced by sintering of glass powders compacts followed by a suitable heat treatment to promote the nucleation and crystallization phenomena. Furthermore, selected parent glass compositions were doped with several functional ions and an attempt to understand their effects on the glass structure, sintering ability and on the in vitro bio-degradation and biomineralization behaviours of the glasses was made. The effects of the same variables on the devitrification (nucleation and crystallization) behaviour of glasses to form bioactive glass-ceramics were also investigated. Some of the glasses exhibited high bio-mineralization rates, expressed by the formation of a surface hydroxyapatite layer within 1-12 h of immersion in a simulated body fluid (SBF) solution. All the glasses showed relatively lower degradation rates in comparison to that of 45S5 Bioglass. Some of the glasses showed very good in vitro behaviour and the glasses co-doped with zinc and strontium showed an in vitro dose dependent behaviour. The as-designed bioactive glasses and glass

Plutonium scrap waste processing based on aqueous nitrate and chloride media

International Nuclear Information System (INIS)

Navratil, J.D.

1985-01-01

A brief review of plutonium scrap aqueous waste processing technology at Rocky Flats is given. Nitric acid unit operations include dissolution and leaching, anion exchange purification and precipitation. Chloride waste processing consists of cation exchange and carbonate precipitation. Ferrite and carrier precipitation waste treatment processes are also described. 3 figs

Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

Science.gov (United States)

Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

2017-02-21

Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

Bactericidal strontium-releasing injectable bone cements based on bioactive glasses

OpenAIRE

Brauer, Delia S.; Karpukhina, Natalia; Kedia, Gopal; Bhat, Aditya; Law, Robert V.; Radecka, Izabela; Hill, Robert G.

2013-01-01

Strontium-releasing injectable bone cements may have the potential to prevent implant-related infections through the bactericidal action of strontium, while enhancing bone formation in patients suffering from osteoporosis. A melt-derived bioactive glass (BG) series (SiO2–CaO–CaF2–MgO) with 0–50% of calcium substituted with strontium on a molar base were produced. By mixing glass powder, poly(acrylic acid) and water, cements were obtained which can be delivered by injection and set in situ, gi...

Demonstration test on manufacturing 200 l drum inner shielding material for recycling of reactor operating metal scrap

International Nuclear Information System (INIS)

Umemura, A.; Kimura, K.; Ueno, H.

1993-01-01

Low-level reactor wastes should be safely recycled considering those resource values, the reduction of waste disposal volume and environmental effects. The reasonable recycling system of reactor operating metal scrap has been studied and it was concluded that the 200 liter drum inner shielding material is a very promising product for recycling within the nuclear industry. The drum inner shielding material does not require high quality and so it is expected to be easily manufactured by melting and casting from roughly sorted scrap metals. This means that the economical scrap metal recycling system can be achieved by introducing it. Furthermore its use will ensure safety because of being contained in a drum. In order to realize this recycling system with the drum inner shielding material, the demonstration test program is being conducted. The construction of the test facility, which consists of a melting and refining furnace, a casting apparatus, a machining apparatus etc., was finishing in September, 1992

Synthesis of high purity tungsten nanoparticles from tungsten heavy alloy scrap by selective precipitation and reduction route

International Nuclear Information System (INIS)

Kamal, S.S. Kalyan; Sahoo, P.K.; Vimala, J.; Shanker, B.; Ghosal, P.; Durai, L.

2016-01-01

In this paper we report synthesis of tungsten nanoparticles of high purity >99.7 wt% from heavy alloy scrap using a novel chemical route of selective precipitation and reduction. The effect of Poly(vinylpyrrolidone) polymer on controlling the particle size is established through FTIR spectra and corroborated with TEM images, wherein the average size decreased form 210 to 45 nm with increasing PVP content from zero to 2 g under different experimental conditions. This process is economical as raw material is a scrap and the efficiency of the reaction is >95%. - Highlights: • Tungsten nanoparticles were synthesized from tungsten heavy alloy scrap. • A novel chemical route of precipitation and reduction with Poly(vinylpyrrolidone) polymer as stabilizer is reported. • The average size decreased form 210 to 45 nm with increasing PVP content from zero to 2 g. • High pure tungsten nanoparticles of >99.7% purity could be synthesized using this route. • Efficiency of the reaction is >95%.

Exclusion, Exemption and Clearance in the Frame of the Control and Management of Inadvertent Radioactive Material in Scrap Metal

International Nuclear Information System (INIS)

Gonzalez, Abel J.

2011-01-01

Radioactive substances are incorporated into materials, goods, merchandises, products and in scrap and, as scrap would recycle into new produce, the process of introduction of radioactive susbtanaces into commodities will continue. The situation is unstoppable and requires straightforward solutions. The problem is global and therefore the solution(s) should be global. A clear intergovernmental agreement is needed establishing to what extent commodities should be regulated

Microwave melt and offgas analysis results from a Ferro Corporation reg-sign glass frit

International Nuclear Information System (INIS)

Phillips, J.A.; Hoffman, C.R.; Knutson, P.T.

1995-03-01

In support of the Residue Treatment Technology (RTT) Microwave Solidification project, Waste Projects and Surface Water personnel conducted a series of experiments to determine the feasibility of encapsulating a surrogate sludge waste using the microwave melter. The surrogate waste was prepared by RTT and melted with five varying compositions of low melting glass frit supplied by the Ferro Corporation. Samples were melted using a 50% waste/50% glass frit and a 47.5% waste/47.5% glass frit/5% carbon powder. This was done to evaluate the effectiveness of carbon at reducing a sulfate-based surface scale which has been observed in previous experiments and in full-scale testing. These vitrified samples were subsequently submitted to Environmental Technology for toxicity characteristic leaching procedure (TCLP) testing. Two of the five frits tested in this experiment merit further evaluation as raw materials for the microwave melter. Ferro frit 3110 with and without carbon powder produced a crystalline product which passed TCLP testing. The quality of the melt product could be improved by increasing the melting temperature from 900 degrees C to approximately 1150-1200 degrees C. Ferro frit 3249 produced the optimal quality of glass based on visual observations, but failed TCLP testing for silver when melted without carbon powder. This frit requires a slightly higher melting temperature (≥ 1200 degrees C) compared to frit 3110 and produces a superior product. In conjunction with this work, Surface Water personnel conducted offgas analyses using a Thermal Desorption Mass Spectrometer (TDMS) on selected formulations. The offgas analyses identified and quantified water vapor (H 2 O), oxygen (O 2 ) and carbon oxides (CO and CO 2 ), sulfur (S) and sulfur oxides (SO and SO 2 ), and nitrogen (N 2 ) and nitrogen oxides (NO and NO 2 ) that volatilized during glass formation

Assessment of recycling or disposal alternatives for radioactive scrap metal

International Nuclear Information System (INIS)

Murphie, W.E.; Lilly, M.J. III

1993-01-01

The US Department of Energy, Office of Environmental Restoration and Waste Management, is participating with the Organization for Economic Cooperation and Development (OECD) is an evaluation of management alternatives for radioactive scarp metals. For this purpose, Argonne National Laboratory is assessing alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and/or disposal process alternatives (with metal replacement). Findings will be presented in a report from the OECD Task Group. This paper focuses on the radiological risk assessment and dose estimate sensitivity analysis. A ''tiered'' concept for release categories, with and without use restrictions, is being developed. Within the tiers, different release limits may be indicated for specific groupings of radionuclides. Depending on the spectrum of radionuclides that are present and the level of residual activity after decontamination and/or smelting, the scrap may be released for unrestricted public use or for specified public uses, or it may be recycled within the nuclear industry. The conversatism of baseline dose estimates is examined, and both more realistic parameter values and protective measures for workers are suggested

Preparation of nano-iron oxide red pigment powders by use of cyanided tailings

International Nuclear Information System (INIS)

Li Dengxin; Gao Guolong; Meng Fanling; Ji Chong

2008-01-01

On one hand, cyanided tailings are one kind of pollutants. On the other hand, they contain a lot of valuable elements. So utilization of them can bring social and environmental benefits. In this paper, cyanided tailings were used to prepare nano-iron oxide red pigment powders by an ammonia process with urea as precipitant. At first, cyanided tailings were oxidized by nitric acid. Then, the oxidizing mixture was separated into solid and liquid parts. The liquid mixture was reduced by scrap iron and the impurity of it was removed by use of NH 3 .H 2 O. Then, the seed crystal of γ-FeOOH was obtained, when the pure liquid reacted with ammonia liquid at the selected experimental conditions. At last, nano-iron oxide red pigment powders were prepared. The structure, morphology and size distribution of seed crystal and iron oxide red were characterized systematically by means of X-ray diffraction (XRD), transmission electron microscope (TEM) and laser particle size analyzer (LPSA). The results revealed that typical iron oxide nanoparticles were α-Fe 2 O 3 with particle size of 50-70 nm. Furthermore, the factors that affected the hue and quality of the seed crystal and iron oxide red pigment were also discussed

Direct vitrification of plutonium-containing materials (PCM`s) with the glass material oxidation and dissolution system (GMODS)

Energy Technology Data Exchange (ETDEWEB)

Forsberg, C.W. Beahm, E.C.; Parker, G.W.; Rudolph, J.C.; Haas, P.A.; Malling, G.F.; Elam, K.; Ott, L.

1995-10-30

The end of the cold war has resulted in excess PCMs from nuclear weapons and associated production facilities. Consequently, the US government has undertaken studies to determine how best to manage and dispose of this excess material. The issues include (a) ensurance of domestic health, environment, and safety in handling, storage, and disposition, (b) international arms control agreements with Russia and other countries, and (c) economics. One major set of options is to convert the PCMs into glass for storage or disposal. The chemically inert characteristics of glasses make them a desirable chemical form for storage or disposal of radioactive materials. A glass may contain only plutonium, or it may contain plutonium along with other radioactive materials and nonradioactive materials. GMODS is a new process for the direct conversion of PCMs (i.e., plutonium metal, scrap, and residues) to glass. The plutonium content of these materials varies from a fraction of a percent to pure plutonium. GMODS has the capability to also convert other metals, ceramics, and amorphous solids to glass, destroy organics, and convert chloride-containing materials into a low-chloride glass and a secondary clean chloride salt strewn. This report is the initial study of GMODS for vitrification of PCMs as input to ongoing studies of plutonium management options. Several tasks were completed: initial analysis of process thermodynamics, initial flowsheet analysis, identification of equipment options, proof-of-principle experiments, and identification of uncertainties.

The detection and assessment of radioactive parts in scrap - a technical and legal challenge

International Nuclear Information System (INIS)

Rieck, W.

1999-01-01

According to the requirements of the European steel industry, delivery of radioactive contaminated metallurgical scrap in excess of natural level has to be excluded. Therefore, in Germany alone, more than 100 high-sensitive gate monitors were installed during the last few years at steel mills and scrap handling facilities. This has resulted in not only tighter protection from an erroneous melting of radioactive sources but also in a great increase in number of reported findings than before. Aside from a small number of sealed sources, the majority of detections concern natural radioactive scale and contamination, mostly from fission and activation products as well as traces of nuclear fuel. Practical and legal problems regarding the application of the regulations on radioactivity protection are demonstrated and discussed. (author)

History and trends of bioactive glass-ceramics.

Science.gov (United States)

Montazerian, Maziar; Dutra Zanotto, Edgar

2016-05-01

The interest around bioactive glass-ceramics (GCs) has grown significantly over the last two decades due to their appropriate biochemical and mechanical properties. The intense research effort in this field has led to some new commercial products for biomedical applications. This review article begins with the basic concepts of GC processing and development via controlled heat treatments of monolithic pieces or sinter-crystallization of powdered glasses. We then go on to describe the processing, properties, and applications of some commercial bioactive GCs and discuss selected valuable reported researches on several promising types of bioactive GCs. The article finishes with a section on open relevant research directions for bioactive GC development. © 2016 Wiley Periodicals, Inc.

Considerations in recycling contaminated scrap metal and rubble

International Nuclear Information System (INIS)

Kluk, A.F.; Hocking, E.K.

1992-01-01

Management options for the Department of Energy's increasing amounts of contaminated scrap metal and rubble include reuse as is, disposal, and recycling. Recycling, with its promise of resource recovery, virgin materials conservation, and land disposal minimization, emerges as a preferred management technique. Implementing a cost effective recycling program requires resolution of several issues including: establishing release limits for contaminants, controlling use of recycled materials creating effective public communication programs; developing economical, reliable assay technologies; managing secondary waste streams, expanding availability of unrestricted markets; and solving conflicting legal considerations

Structure, phases, and mechanical response of Ti-alloy bioactive glass composite coatings

Energy Technology Data Exchange (ETDEWEB)

Nelson, G.M.; Nychka, J.A. [Department of Chemical and Materials Engineering, University of Alberta, 7th Floor, Electrical and Computer Engineering Research Facility, Edmonton, Alberta T6G 2V4 (Canada); McDonald, A.G., E-mail: andre2@ualberta.ca [Department of Mechanical Engineering, University of Alberta, 4-9 Mechanical Engineering Building, Edmonton, Alberta T6G 2G8 (Canada)

2014-03-01

Porous titanium alloy-bioactive glass composite coatings were manufactured via the flame spray deposition process. The porous coatings, targeted for orthodontic and bone-fixation applications, were made from bioactive glass (45S5) powder blended with either commercially pure titanium (Cp-Ti) or Ti-6Al-4V alloy powder. Two sets of spray conditions, two metallic particle size distributions, and two glass particle size distributions were used for this study. Negative control coatings consisting of pure Ti-6Al-4V alloy or Cp-Ti were sprayed under both conditions. The as-sprayed coatings were characterized through quantitative optical cross-sectional metallography, X-ray diffraction (XRD), and ASTM Standard C633 tensile adhesion testing. Determination of the porosity and glassy phase distribution was achieved by using image analysis in accordance with ASTM Standard E2109. Theoretical thermodynamic and heat transfer modeling was conducted to explain experimental observations. Thermodynamic modeling was performed to estimate the flame temperature and chemical environment for each spray condition and a lumped capacitance heat transfer model was developed to estimate the temperatures attained by each particle. These models were used to establish trends among the choice of alloy, spray condition, and particle size distribution. The deposition parameters, alloy composition, and alteration of the feedstock powder size distribution had a significant effect on the coating microstructure, porosity, phases present, mechanical response, and theoretical particle temperatures that were attained. The most promising coatings were the Ti-6Al-4V-based composite coatings, which had bond strength of 20 ± 2 MPa (n = 5) and received reinforcement and strengthening from the inclusion of a glassy phase. It was shown that the use of the Ti-6Al-4V-bioactive glass composite coatings may be a superior choice due to the possible osteoproductivity from the bioactive glass, the potential ability to

Designing porous metallic glass compact enclosed with surface iron oxides

Energy Technology Data Exchange (ETDEWEB)

Cho, Jae Young; Park, Hae Jin; Hong, Sung Hwan; Kim, Jeong Tae; Kim, Young Seok; Park, Jun-Young; Lee, Naesung [Hybrid Materials Center (HMC), Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 143-747 (Korea, Republic of); Seo, Yongho [Graphene Research Institute (GRI) & HMC, Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 143-747 (Korea, Republic of); Park, Jin Man, E-mail: jinman_park@hotmail.com [Global Technology Center, Samsung Electronics Co., Ltd, 129 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-742 (Korea, Republic of); Kim, Ki Buem, E-mail: kbkim@sejong.ac.kr [Hybrid Materials Center (HMC), Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 143-747 (Korea, Republic of)

2015-06-25

Highlights: • Porous metallic glass compact was developed using electro-discharge sintering process. • Uniform PMGC can only be achieved when low electrical input energy was applied. • Functional iron-oxides were formed on the surface of PMGCs by hydrothermal technique. - Abstract: Porous metallic glass compact (PMGC) using electro-discharge sintering (EDS) process of gas atomized Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} metallic glass powder was developed. The formation of uniform PMGC can only be achieved when low electrical input energy was applied. Functional iron-oxides were formed on the surface of PMGCs by hydrothermal technique. This finding suggests that PMGC can be applied in the new area such as catalyst via hydrothermal technique and offer a promising guideline for using the metallic glasses as a potential functional application.

Advanced technologies for decontamination and conversion of scrap metal

International Nuclear Information System (INIS)

Muth, T.R.; Shasteen, K.E.; Liby, A.L.

1995-01-01

The Department of Energy (DOE) accumulated large quantities of radioactive scrap metal (RSM) through historic maintenance activities. The Decontamination and Decommissioning (D ampersand D) of major sites formerly engaged in production of nuclear materials and manufacture of nuclear weapons will generate additional quantities of RSM, as much as 3 million tons of such metal according to a recent study. The recycling of RSM is quickly becoming appreciated as a key strategy in DOE's cleanup of contaminated sites and facilities

Synthesis, characterization, bioactivity and antibacterial studies of silver doped calcium borosilicate glass-ceramics

Science.gov (United States)

Kumar, Alesh; Mariappan, C. R.

2018-04-01

Bioactive glass-ceramics 45.8 mol% SiO- 45.8 CaO - 8.4 B2O3 doped with Ag2O were synthesized by sol-gel method. The glass-ceramic nature of samples was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Fourier transform infrared (FT-IR) spectra reveal the probable stretching and bending vibration modes of silicate and borate groups. UV-Visible spectra reveal the presence of Ag+ ions and metallic Ag in the glass matrix for Ag2O doped ceramic sample. Biocompatibility of the glass nature of samples was studied by soaking of samples in Dulbecco's Modified Eagle's Medium (DMEM) with subsequent XRD studies. It was found that bone-like apatite formation on the glasses after soaked in DMEM. Antibacterial studies of glass ceramics powder against gram positive and negative microorganisms were carried out.

Current status of scrap metal recycling and reuse in USA and European countries

International Nuclear Information System (INIS)

Matsumoto, Akira

1997-01-01

Recycling and reuse of natural resources has become a global issue to be pursued, but less effective without voluntary efforts from the every industries and of the individuals. In Japan, recycling and reuse of the scrap metal from dismantling of the nuclear facilities are currently noticed as a promising option and the responsible government organizations just started activities to develope the system for enabling and encouraging the nuclear facility owners to recycle their waste. Coincidently, there have been many reports published recently, which inform successful results of the method and the activities of the international organizations for the same intention. Taking this opportunity, current trends of scrap metal recycling and reuse in the experienced countries are reviewed and the proposals from IAEA, EC and OECD/NEA on the relating issues are summarized and compared in this paper. (author)

Efficient One-Step Electrolytic Recycling of Low-Grade and Post-Consumer Magnesium Scrap

Energy Technology Data Exchange (ETDEWEB)

Adam C. Powell, IV

2012-07-19

Metal Oxygen Separation Technologies, Inc. (abbreviated MOxST, pronounced most) and Boston University (BU) have developed a new low-cost process for recycling post-consumer co-mingled and heavily-oxidized magnesium scrap, and discovered a new chemical mechanism for magnesium separations in the process. The new process, designated MagReGenTM, is very effective in laboratory experiments, and on scale-up promises to be the lowest-cost lowest-energy lowest-impact method for separating magnesium metal from aluminum while recovering oxidized magnesium. MagReGenTM uses as little as one-eighth as much energy as today's methods for recycling magnesium metal from comingled scrap. As such, this technology could play a vital role in recycling automotive non-ferrous metals, particularly as motor vehicle magnesium/aluminum ratios increase in order to reduce vehicle weight and increase efficiency.

Application of ceramic and glass materials in nuclear power plants

International Nuclear Information System (INIS)

Hamnabard, Z.

2008-01-01

Ceramic and glass are high temperature materials that can be used in many fields of application in nuclear industries. First, it is known that nuclear fuel UO 2 is a ceramic material. Also, ability to absorb neutrons without forming long lived radio-nuclides make the non-oxide ceramics attractive as an absorbent for neutron radiation arising in nuclear power plants. Glass-ceramic materials are a new type of ceramic that produced by the controlled nucleation and crystallization of glass, and have several advantages such as very low or null porosity, uniformity of microstructure, high chemical resistance etc. over conventional powder processed ceramics. These ceramic materials are synthesized in different systems based on their properties and applications. In nuclear industries, those are resistant to leaching and radiation damage for thousands of years, Such as glass-ceramics designed for radioactive waste immobilization and machinable glass-ceramics are used. This article introduces requirements of different glass and ceramic materials used in nuclear power plants and have been focused on developments in properties and application of them

Sol-gel synthesis and densification of aluminoborosilicate powders. Part 2: Densification

Science.gov (United States)

Bull, Jeffrey; Selvaduray, Guna; Leiser, Daniel

1992-01-01

Aluminoborosilicate (ABS) powders, high in alumina content, were synthesized by the sol-gel process utilizing four different methods of synthesis. The effect of these methods on the densification behavior of ABS powder compacts was studied. Five regions of shrinkage in the temperature range 25-1184 C were identified. In these regions, the greatest shrinkage occurred between the gel-to-glass transition temperature (T sub g approximately equal to 835 C) and the crystallization transformation temperature (T sub t approximately equal 900 C). The dominant mechanism of densification in this range was found to be viscous sintering. ABS powders were amorphous to x-rays up to T sub t at which a multiphasic structure crystallized. No 2Al2O3.B2O3 was found in these powders as predicted in the phase diagram. Above T sub t, densification was the result of competing mechanisms including grain growth and boria fluxed viscous sintering. Apparent activation energies for densification in each region varied according to the method of synthesis.

Antibacterial effect of bioactive glasses on clinically important anaerobic bacteria in vitro.

Science.gov (United States)

Leppäranta, Outi; Vaahtio, Minna; Peltola, Timo; Zhang, Di; Hupa, Leena; Hupa, Mikko; Ylänen, Heimo; Salonen, Jukka I; Viljanen, Matti K; Eerola, Erkki

2008-02-01

Bioactive glasses (BAGs) of different compositions have been studied for decades for clinical use and they have found many dental and orthopaedic applications. Particulate BAGs have also been shown to have antibacterial properties. This large-scale study shows that two bioactive glass powders (S53P4 and 13-93) and a sol-gel derived material (CaPSiO II) have an antibacterial effect on 17 clinically important anaerobic bacterial species. All the materials tested demonstrated growth inhibition, although the concentration and time needed for the effect varied depending on the BAG. Glass S53P4 had a strong growth-inhibitory effect on all pathogens tested. Glass 13-93 and sol-gel derived material CaPSiO II showed moderate antibacterial properties.

Decolorization of dyeing wastewater in continuous photoreactors using tio2 coated glass tube media

Directory of Open Access Journals (Sweden)

Jutaporn Chanathaworn

2014-02-01

Full Text Available The present study deals with a decolorization development of malachite green (MG dyeing wastewater using TiO2 thin films coated glass tube media in photoreactor. The TiO2 photocatalyst was synthesized by three methods: TTIP sol-gel, TiO2 powder-modified sol, and TiO2 powder suspension coating on raschig ring glass tube media and was investigated crystallinity phase by SEM, XRD, and AFM. Degradation kinetics of the dyeing wastewater by photocatalytic was carried out under UV light irradiation. The Langmuir first-order model provided the best fit to the experimental data. The catalyst prepared by powder suspension technique and coated on glass tube had given the highest of decolorization kinetics and efficiency. Continuous photoreactor packed with the TiO2 coating media was designed and proven to be the high effectiveness for MG dyeing degradation and stable throughout the recyclability test. The light intensity, dye solution flow rate, and TiO2 loading were the most important parameters that response to decolorization efficiency. The optimum condition of photo decolorization of MG dye solution can be obtained from RSM model. Effectiveness of the synthesized TiO2 thin films using suspension technique and the continuous photoreactor design were obtained with a great potential to be proven for wastewater treatment at industrial scale.

Bioactive glasses and glass-ceramics

Directory of Open Access Journals (Sweden)

de Aza, P. N.

2007-04-01

Full Text Available Since the late 1960´s, a great interest in the use of bioceramic materials for biomedical applications has been developed. In a previous paper, the authors reviewed crystalline bioceramic materials “sensus stricto”, it is to say, those ceramic materials, constituted for non-metallic inorganic compounds, crystallines and consolidates by thermal treatment of powders at high temperature. In the present review, the authors deal with those called bioactive glasses and glassceramics. Although all of them are also obtained by thermal treatment at high temperature, the first are amorphous and the second are obtained by devitrification of a glass, although the vitreous phase normally prevails on the crystalline phases. After an introduction to the concept of bioactive materials, a short historical review of the bioactive glasses development is made. Its preparation, reactivity in physiological media, mechanism of bonding to living tissues and mechanical strength of the bone-implant interface is also reported. Next, the concept of glass-ceramic and the way of its preparation are exposed. The composition, physicochemical properties and biological behaviour of the principal types of bioactive glasses and glass-ceramic materials: Bioglass®, Ceravital®, Cerabone®, Ilmaplant® and Bioverit® are also reviewed. Finally, a short review on the bioactive-glass coatings and bioactive-composites and most common uses of bioactive-glasses and glass-ceramics are carried out too.

Desde finales de los años sesenta, se ha despertado un gran interés por el uso de los materiales biocerámicos para aplicaciones biomédicas. En un trabajo previo, los autores hicieron una revisión de los denominados materiales biocerámicos cristalinos en sentido estricto, es decir, de aquellos materiales, constituidos por compuestos inorgánicos no metálicos, cristalinos y consolidados mediante tratamientos térmicos a altas temperaturas. En el presente trabajo, los autores

X-ray spectrometric determination of glass content of melts incorporating radioactive waste: a feasibility study

International Nuclear Information System (INIS)

Slates, R.V.

1978-09-01

X-ray fluorescence spectrometry was evaluated for the determination of glass content and homogeneity of glass incorporating high-level radioactive waste. Accuracy and precision were determined for analyses of Al 2 O 3 , SiO 2 , CaO, TiO 2 , MnO, Fe 2 O 3 , and NiO in specimens of known composition. These specimens were prepared by fusing powdered glass with nonradioactive synthetic waste. Matrix effects of sodium on these analyses were specifically evaluated. X-ray fluorescence spectrometry was shown to be applicable to the proposed determinations by comparing the known glass contents of 14 glass waste compositions with those calculated from experimentally determined concentrations of SiO or TiO 2

Synthesis of calcium phosphate hydrogel from waste incineration fly ash and bone powder

International Nuclear Information System (INIS)

Fukui, Kunihiro; Arimitsu, Naoki; Kidoguchi, Satoshi; Yamamoto, Tetsuya; Yoshida, Hideto

2009-01-01

Waste incineration fly ash and bone powder could be successfully recycled into calcium phosphate hydrogel, a type of fast proton conductor. Various properties of the intermediate and calcium phosphate hydrogel from them were characterized and compared with that from calcium carbonate reagent. It was found that the intermediate from the incineration fly ash and calcium phosphate glass was more brittle than that from bone powder and calcium carbonate reagent. The electric conductivity of crystallized hydrogel obtained from all raw materials increases exponentially with temperature. However, the crystallized hydrogel from incineration fly ash has lower electric conductivity and lower crystallinity than that from bone powder and the reagent. Moreover, the difference in electric conductivity between these crystallized hydrogels decreases with temperature. Compared with using the reagent as a raw material, bone powder provides a 25% reduction in the usage of H 3 PO 4 to acquire the crystallized hydrogel which has the highest conductivity. These experimental results suggest that the incineration fly ash and bone powder are useful calcium sources for the synthesis of calcium phosphate hydrogel

Factors influencing the preparation of silver-coated glass frit with polyvinyl-pyrrolidone

Science.gov (United States)

Xiang, Feng; Gan, Weiping

2018-01-01

In this work, a new electroless silver plating method for the synthesis of silver-coated glass frit composite powders with good morphology has been proposed and the polyvinyl-pyrrolidone (PVP) was used the activating agent. It was found that the weight ratio of PVP to glass frit affected the distribution and number of silver nanoparticles. Moreover, the loading capacity of the glass frit, the pH value and reaction temperature could influence the size of the silver nanoparticles and morphology of silver on the surface of glass frit. The as-prepared silver-coated glass frit was used to prepare a silver paste using an optimized process to form silver nanoparticles with uniform size and high density. The silver paste with silver-coated glass frit increased the photovoltaic conversion efficiency of silicon solar cells by 0.271% compared with the silver paste prepared with pure glass frit. The silver nanoparticles can promoted the precipitation of Ag crystallites on the silicon wafer. Therefore, the silver-coated glass frit can further optimize and enhance the electrical performance of solar cells.

The Scrap Collection per Industry Sector and the Circulation Times of Steel in the U.S. between 1900 and 2016, Calculated Based on the Volume Correlation Model

Directory of Open Access Journals (Sweden)

Alicia Gauffin

2018-05-01

Full Text Available On the basis of the Volume Correlation Model (VCM as well as data on steel consumption and scrap collection per industry sector (construction, automotive, industrial goods, and consumer goods, it was possible to estimate service lifetimes of steel in the United States between 1900 and 2016. Input data on scrap collection per industry sector was based on a scrap survey conducted by the World Steel Association for a static year in 2014 in the United States. The lifetimes of steel calculated with the VCM method were within the range of previously reported measured lifetimes of products and applications for all industry sectors. Scrapped (and apparent lifetimes of steel compared with measured lifetimes were calculated to be as follows: a scrapped lifetime of 29 years for the construction sector (apparent lifetime: 52 years compared with 44 years measured in 2014. Industrial goods: 16 (27 years compared with 19 years measured in 2010. Consumer goods: 12 (14 years compared with 13 years measured in 2014. Automotive sector: 14 (19 years compared with 17 years measured in 2011. Results show that the VCM can estimate reasonable values of scrap collection and availability per industry sector over time.

Continuous micro-feeding of fine cohesive powders actuated by pulse inertia force and acoustic radiation force in ultrasonic standing wave field.

Science.gov (United States)

Wang, Hongcheng; Wu, Liqun; Zhang, Ting; Chen, Rangrang; Zhang, Linan

2018-07-10

Stable continuous micro-feeding of fine cohesive powders has recently gained importance in many fields. However, it remains a great challenge in practice because of the powder aggregate caused by interparticle cohesive forces in small capillaries. This paper describes a novel method of feeding fine cohesive powder actuated by a pulse inertia force and acoustic radiation force simultaneously in an ultrasonic standing wave field using a tapered glass nozzle. Nozzles with different outlet diameters are fabricated using glass via a heating process. A pulse inertia force is excited to drive powder movement to the outlet section of the nozzle in a consolidated columnar rod mode. An acoustic radiation force is generated to suspend the particles and make the rod break into large quantities of small agglomerates which impact each other randomly. So the aggregation phenomenon in the fluidization of cohesive powders can be eliminated. The suspended powder is discharged continuously from the nozzle orifice owing to the self-gravities and collisions between the inner particles. The micro-feeding rates can be controlled accurately and the minimum values for RespitoseSV003 and Granulac230 are 0.4 mg/s and 0.5 mg/s respectively. The relative standard deviations of all data points are below 0.12, which is considerably smaller than those of existing vibration feeders with small capillaries. Copyright © 2018 Elsevier B.V. All rights reserved.

Surface analysis of Borkron glass for neutron optics applications

International Nuclear Information System (INIS)

Farnoux, B.; Maaza, M.; Maaza, M.; Samuel, F.; Sella, C.

1991-01-01

Grazing Angle Neutron Reflectometry, Optical and Mechanical Roughness Profilometry techniques have been used to study the effects of the polishing operations on the surface of Borkron Schott glass (special borosilicate glass for neutron optics applications) as the polishing tool pressure P and the mean grain size of the polishing powder Φ. The neutron reflectivity investigations have shown that there is formation of a layer at the surface glass substrate. This layer is less dense than the bulk substrate and its thickness is around 60A. The optical and mechanical profilometry measurements have shown that both roughness and waviness decrease with P and Φ. All the experimental results show a good correlation between the neutron refractive index, the thickness and the roughness of the surface layer and the waviness of the glass surface with the two mechanical polishing parameters. The previous techniques have been completed by Secondary Ion Mass Spectroscopy and Atomic Force Microscopy measurements

Challenges in the Management of Potentially Contaminated Scrap Metal

Energy Technology Data Exchange (ETDEWEB)

Meehan, R.W., E-mail: meehanrw@em.doe.gov [US Department of Energy, National Nuclear Security Administration, Washington, DC (United States)

2011-07-15

This paper describes the background and current status of the management of potentially contaminated metals and materials at the US Department of Energy (DOE) sites across the USA. The current DOE policy prohibiting the release of metal scrap for recycling from radiation areas is explained. Finally, a potential path forward to competently assess, characterize and clear material from radiological control is proposed that uses a combination of administrative processes and empirical techniques that are valid irrespective of the standard used for clearance. (author)

Glass microspheres for medical applications

Science.gov (United States)

Conzone, Samuel David

Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass

Glassy slag: A complementary waste form to homogeneous glass for the implementation of MAWS in treating DOE low level/mixed wastes

International Nuclear Information System (INIS)

Feng, X.; Ordaz, G.; Krumrine, P.

1994-01-01

Glassy slag waste forms are being developed to complement glass waste forms in implementing the Minimum Additive Waste Stabilization (MAWS) Program for supporting DOE's environmental restoration efforts. These glassy slags are composed of various metal oxide crystalline phases embedded in an alumino-silicate glass phase. The slags are appropriate final waste forms for waste streams that contain large amounts of scrap metals and elements with low solubilities in glass, and that have low-flux contents. Homogeneous glass waste forms are appropriate for wastes with sufficient fluxes and low metal contents. Therefore, utilization of both glass and glassy slag waste forms will make vitrification technology applicable to the treatment of a much larger range of radioactive and mixed wastes. The MAWS approach was a plied to glassy slags by blending multiple waste streams to produce the final waste form, minimizing overall waste form volume and reducing costs. The crystalline oxide phases formed in the glassy slags can be specially formulated so that they are very durable and contain hazardous and radioactive elements in their lattice structures. The Structural Bond Strength (SBS) Model was used to predict the chemical durability of the product from the slag composition so that optimized slag compositions could be obtain with a limited number of crucible melts and testing

Study of the mechanical stability and bioactivity of Bioglass(®) based glass-ceramic scaffolds produced via powder metallurgy-inspired technology.

Science.gov (United States)

Boccardi, Elena; Melli, Virginia; Catignoli, Gabriele; Altomare, Lina; Jahromi, Maryam Tavafoghi; Cerruti, Marta; Lefebvre, Louis-Philippe; De Nardo, Luigi

2016-02-02

Large bone defects are challenging to heal, and often require an osteoconductive and stable support to help the repair of damaged tissue. Bioglass-based scaffolds are particularly promising for this purpose due to their ability to stimulate bone regeneration. However, processing technologies adopted so far do not allow for the synthesis of scaffolds with suitable mechanical properties. Also, conventional sintering processes result in glass de-vitrification, which generates concerns about bioactivity. In this work, we studied the bioactivity and the mechanical properties of Bioglass(®) based scaffolds, produced via a powder technology inspired process. The scaffolds showed compressive strengths in the range of 5-40 MPa, i.e. in the upper range of values reported so far for these materials, had tunable porosity, in the range between 55 and 77%, and pore sizes that are optimal for bone tissue regeneration (100-500 μm). We immersed the scaffolds in simulated body fluid (SBF) for 28 d and analyzed the evolution of the scaffold mechanical properties and microstructure. Even if, after sintering, partial de-vitrification occurred, immersion in SBF caused ion release and the formation of a Ca-P coating within 2 d, which reached a thickness of 10-15 μm after 28 d. This coating contained both hydroxyapatite and an amorphous background, indicating microstructural amorphization of the base material. Scaffolds retained a good compressive strength and structural integrity also after 28 d of immersion (6 MPa compressive strength). The decrease in mechanical properties was mainly related to the increase in porosity, caused by its dissolution, rather than to the amorphization process and the formation of a Ca-P coating. These results suggest that Bioglass(®) based scaffolds produced via powder metallurgy-inspired technique are excellent candidates for bone regeneration applications.

Mixing of zeolite powders and molten salt

International Nuclear Information System (INIS)

Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

1996-01-01

Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product

Consolidated waste forms: glass marbles and ceramic pellets

International Nuclear Information System (INIS)

Treat, R.L.; Rusin, J.M.

1982-05-01

Glass marbles and ceramic pellets have been developed at Pacific Northwest Laboratory as part of the multibarrier concept for immobilizing high-level radioactive waste. These consolidated waste forms served as substrates for the application of various inert coatings and as ideal-sized particles for encapsulation in protective matrices. Marble and pellet formulations were based on existing defense wastes at Savannah River Plant and proposed commercial wastes. To produce marbles, glass is poured from a melter in a continuous stream into a marble-making device. Marbles were produced at PNL on a vibratory marble machine at rates as high as 60 kg/h. Other marble-making concepts were also investigated. The marble process, including a lead-encapsulation step, was judged as one of the more feasible processes for immobilizing high-level wastes. To produce ceramic pellets, a series of processing steps are required, which include: spray calcining - to dry liquid wastes to a powder; disc pelletizing - to convert waste powders to spherical pellets; sintering - to densify pellets and cause desired crystal formation. These processing steps are quite complex, and thereby render the ceramic pellet process as one of the least feasible processes for immobilizing high-level wastes

Role of glass structure in defining the chemical dissolution behavior, bioactivity and antioxidant properties of zinc and strontium co-doped alkali-free phosphosilicate glasses.

Science.gov (United States)

Kapoor, Saurabh; Goel, Ashutosh; Tilocca, Antonio; Dhuna, Vikram; Bhatia, Gaurav; Dhuna, Kshitija; Ferreira, José M F

2014-07-01

We investigated the structure-property relationships in a series of alkali-free phosphosilicate glass compositions co-doped with Zn(2+) and Sr(2+). The emphasis was laid on understanding the structural role of Sr(2+) and Zn(2+) co-doping on the chemical dissolution behavior of glasses and its impact on their in vitro bioactivity. The structure of glasses was studied using molecular dynamics simulations in combination with solid state nuclear magnetic resonance spectroscopy. The relevant structural properties are then linked to the observed degradation behavior, in vitro bioactivity, osteoblast proliferation and oxidative stress levels. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy and scanning electron microscopy-energy-dispersive spectroscopy after immersion of glass powders/bulk in simulated body fluid (SBF) for time durations varying between 1h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the glasses exhibit hydroxyapatite formation on their surface within 1-3h of their immersion in SBF. The cellular responses were observed in vitro on bulk glass samples using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of zinc and strontium released from the glasses is also discussed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Obtaining a glass-ceramic material from a steel slag mixed with glass cullet; Obtencion de un material vitroceramico a partir de una escoria de aceria mezclada con vidrio de desecho

Energy Technology Data Exchange (ETDEWEB)

Oziel Mendez Guerrero, D.; Alicia Vazquez Mendez, B.; Alvarez Mendez, A.

2011-07-01

In this paper, the qualitative, quantitative and thermal characterization of a steel slag and glass cullet of high generation rate in northern Mexico were made in order to use these wastes as raw materials in the production of glass ceramics. The particle size was controlled at sizes = 75 micrometers and the major components of the slag were located in a phase equilibrium diagram for proposing a reaction temperature that leaded to the starting glass. Later, heat treatments were performed to obtain the glass ceramics. The materials were characterized by powder X-ray diffraction (XRD), differential thermal analysis coupled with thermal gravimetric analysis (DTA-TGA), reflected light optical microscopy (RLOM) and scanning electron microscopy (SEM). Subsequently, Vickers microhardness and chemical resistance tests were performed, which enabled us to propose an application of the glass ceramics. (Author) 18 refs.

Scrap automotive electronics: A mini-review of current management practices.

Science.gov (United States)

Cucchiella, Federica; D'Adamo, Idiano; Rosa, Paolo; Terzi, Sergio

2016-01-01

End-of-life vehicles, together with waste from electric and electronic equipment, are known as an important source of secondary raw materials. For many years, their recovery has allowed the restoring of great amounts of metals for new cars production. This article provides a comprehensive mini-review on the end-of-life vehicles recycling topic between 2000 and 2014, with a particular focus on automotive electronics recycling. In fact, in the last years, experts focused their attention on a better exploitation of automotive shredder residue fraction, but not sufficiently on eventual electronic scraps embedded in it. Hence, studies assessing the value embedded in these scraps are rarely available in literature, causing an important gap in both recycling policies and research. The fact that, at present, the management of electronic control units (the most valuable component among automotive electronic equipment) is, as yet, off the radar in both end-of-life vehicles and waste from electric and electronic equipment Directives demonstrates the theory. Of course, their recycling would not contribute in a relevant way to reach the weighted-based recycling and recovery targets characterising current regulations, but would be very important under a critical raw materials recovery view. Results coming from the literature analysis confirm these assumptions. © The Author(s) 2015.

a comparison of bond perform with reinforcements from son of bond ...

African Journals Online (AJOL)

User

steel that are manufactured from metal scraps (re- ... metal scraps from re-cycle obsolete vehicle and machine ..... (PAC) Reinforced With Glass-Fibre-Reinforced. Polymer ... 99 – 113. [8] Abrishami H. H. and Mitchell D. (1992) “Simulation of.

Gained experiences concerning the treatment of radioactive metal scrap from German NPP'S in Studsvik - Gained experience concerning the treatment of radioactive metal scrap from German nuclear power plants

International Nuclear Information System (INIS)

Westerwinter, Boris; Buckanie, Niemma

2014-01-01

The company Gesellschaft fuer Nuklear-Service mbH, Essen/Germany (GNS), operates on behalf of the utilities E.ON, RWE, EnBW and VENE since the nineteen-nineties - amongst its other duties - on the waste management of metal scrap which originates from German nuclear power plants. The main objective within this responsibility is to maximize the value of recyclable fractions for re-use while minimizing the resulting radioactive waste. To achieve the aforementioned objective, melting of metallic scrap proved to be an outstanding choice. The use of this technique combined with all accompanying processes and regulations is accepted by the competent authorities and independent experts as a qualified treatment method over the entire time period. The motivation of this paper is to reflect on the experiences gained concerning the planning, implementation and results, acquired by GNS by using the Studsvik service. The focus will be on characteristics within processing of such campaigns. (authors)

Kinetics of dissolution of a biocide soda-lime glass powder containing silver nanoparticles

International Nuclear Information System (INIS)

Esteban-Tejeda, L.; Silva, A. C. da; Mello-Castanho, S. R.; Pacharroman, C.; Moya, J. S.

2013-01-01

In the present study we have studied the lixiviation kinetics of silver nanoparticles, as well as the solubility of a particulate system ( 2 lixiviation followed a Jander model (α 2 /4 ≈ Kt). It has been proven that nanostructured soda-lime glass/nAg composed by particles <30 μm with a 20 wt% of silver are a strong biocide versus Gram-positive, Gram-negative bacteria and yeasts. This soda-lime glass/nAg acts as a perfect dispenser of silver nanoparticles to the liquid media, avoiding the fast increasing of its concentration over the toxicity limit for human cells and for the environment.

X-ray irradiation induced reduction and nanoclustering of lead in borosilicate glass

NARCIS (Netherlands)

Stanley, H.B.; Banerjee, D.; Breemen, van L.C.A.; Ciston, J.; Liebscher, C.H.; Martis, V.; Merino, D.H.; Longo, A.; Pattison, P.; Peters, G.W.M.; Portale, G.; Sen, Sabyasachi; Bras, W.

2014-01-01

We have studied the formation of nanoparticles in lead sulfide (PbS)-doped borosilicate glass subjected to a two-step nucleation and growth heat treatment using in situ small-angle X-ray scattering (SAXS). The microstructure produced was subsequently characterized using X-ray powder diffraction

USING THE SCRAP TIRES TO PRODUCE A FLEXIBLE COUPLER

OpenAIRE

Tahsean A. Hussain

2018-01-01

The scrap tires considered a problematic source of waste, the old rubber tires causes a big environmental problem that is need much money and effort to disposes it safely. In Iraq there are more than two million used tires disposed to the environment annually. one of the tire’s recycling methods is the use of tire layers to produce a new rubber parts used in the engineering and industrial purposes as the bridges and machines dampers, this trend of recycling doesn’t take a sufficient care comp...

Secure Automated Fabrication: a system design description (SDD), section 1

International Nuclear Information System (INIS)

Konze, G.M.; Thompson, M.L.; Wadekamper, D.C.; Zimmer, J.J.

Information is presented concerning the conversion system to convert purified mixed nitrate solution to MO/sub x/ powder; powder preparation and pellet fabrication; sintering and pin loading; assembly fabrication; and scrap recovery

Porous glass matrix method for encapsulating high-level nuclear wastes

International Nuclear Information System (INIS)

Macedo, P.B.; Tran, D.C.; Simmons, J.H.; Saleh, M.; Barkatt, A.; Simmons, C.J.; Lagakos, N.; DeWitt, E.

1979-01-01

A novel process which uses solidified porous high-silica glass powder to fixate radioactive high-level wastes is described. The process yields cylinders consisting of a core of high-silica glass containing the waste elements in its structure and a protective layer also of high-silica glass completely free of waste elements. The process can be applied to waste streams containing 0 to 100% solids. The core region exhibits a higher coefficient of thermal expansion and a lower glass transition temperature than the outer protective layer. This leads to mechanical strengthening of the glass and good resistance to stress corrosion by the development of a high residual compressive stress on the surface of the sample. Both the core and the protective layer exhibit extremely high chemical durability and offer an effective fixation of the radioactive waste elements, including 239 Pu and 99 Tc which have long half-lives, for calculated periods of more than 1 million years, when temperatures are not allowed to rise above 100 0 C

Fuzzy chance constrained linear programming model for scrap charge optimization in steel production

DEFF Research Database (Denmark)

Rong, Aiying; Lahdelma, Risto

2008-01-01

the uncertainty based on fuzzy set theory and constrain the failure risk based on a possibility measure. Consequently, the scrap charge optimization problem is modeled as a fuzzy chance constrained linear programming problem. Since the constraints of the model mainly address the specification of the product...

United States copper metal and scrap use and trade patterns, 1995‒2014

Science.gov (United States)

Goonan, Thomas G.

2016-06-17

In 1995, China accounted for 10 percent of world copper consumption. By 2014, China accounted for about 49 percent of world copper consumption. This change has affected global copper and copper scrap prices, the sources of copper supply, and U.S. trade of copper-containing materials.

Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

Energy Technology Data Exchange (ETDEWEB)

Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C. [Colorado State University, Department of Civil and Environmental Engineering, Fort Collins, CO (United States)

2008-08-15

Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

International Nuclear Information System (INIS)

Van de Lindt, J.W.; Carraro, J.A.H.; Heyliger, P.R.; Choi, C.

2008-01-01

Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

Photoluminescence and lasing in whispering gallery mode glass microspherical resonators

Energy Technology Data Exchange (ETDEWEB)

Ristić, D. [Ruđer Bošković Institute, Division of Materials Physics, Laboratory for Molecular Physics, Bijenička c. 54, Zagreb (Croatia); Center of Excellence for Advanced Materials and Sensing Devices, Research unit New Functional Materials, Bijenička c. 54, Zagreb (Croatia); Berneschi, S.; Camerini, M. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Farnesi, D.; Pelli, S. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Trono, C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Chiappini, A.; Chiasera, A.; Ferrari, M. [CSMFO Group, Istituto di Fotonica e Nanotecnologie, IFN-CNR, Via alla Cascata 56/C, 38050 Povo-Trento (Italy); Lukowiak, A. [Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, Wroclaw 50-950 (Poland); Dumeige, Y.; Féron, P. [Laboratoire d' Optronique, (CNRS-UMR 6082-Foton), ENSSAT, 6 rue de Kérampont, 22300 Lannion (France); Righini, G.C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Soria, S., E-mail: s.soria@ifac.cnr.it [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Conti, G. Nunzi [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy)

2016-02-15

We report experimental results regarding the development of Er{sup 3+}-doped glass microspherical cavities for the fabrication of compact sources at 1.55 μm. We investigate several different approaches in order to fabricate the microspheres including direct melting of Er{sup 3+}-doped glass powders, synthesis of Er{sup 3+}-doped monolithic microspheres by drawing Er{sup 3+}-doped glass, and coating of silica microspheres with an Er{sup 3+}-doped sol–gel layer. Details of the different fabrication processes are presented together with the photoluminescence characterization in free space configuration of the microspheres and of the glass precursor. We have analyzed the photoluminescence spectra of the whispering gallery modes of the microspheres excited using evanescent coupling and we demonstrate tunable laser action in a wide range of wavelengths around 1.55 μm. As much as 90 μW of laser output power was measured in Er{sup 3+}-doped glass microspheres. - Highlights: • Different approaches in microsphere fabrication and various types of post-processing. • Trimming of photorefractive glass microsphere lasers with UV light. • Peak power record of 90 μW by pumping at 1480 nm.

The regulatory action in the problem of radioactive sources processed as scrap

International Nuclear Information System (INIS)