Thermal decomposition of calcium aluminium phosphate of Thies. [Vaporization of uranium and phosphorus pentoxide

Energy Technology Data Exchange (ETDEWEB)

Allaf, K; Rouanet, A

1984-01-01

This study is related to the work on beneficiation of raw phosphates by thermal processing (selective vaporization). More precisely it deals with the ability of a calcium-aluminium phosphate (ores from Thies) to vaporize selectively as phosphorus pentoxide and uranium contents. Experiments are performed on liquid samples at Tsub(f)

Human exposure to aluminium.

Science.gov (United States)

Exley, Christopher

2013-10-01

Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium.

Determination of Aluminium Content in Aluminium Hydroxide Formulation by FT-NIR Transmittance Spectroscopy

DEFF Research Database (Denmark)

Lai, Xuxin; Zheng, Yiwu; Søndergaard, Ib

2007-01-01

A method for determining the aluminium content of an aluminium hydroxide suspension using near infrared (NIR) transmittance spectroscopy has been developed. Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) was used as reference method. The factors influencing the NIR analysis...... aluminium content in aluminium hydroxide suspension. (c) 2007 Elsevier Ltd. All rights reserved....

Effect of Bio char on Plant Growth and Aluminium Form of Soil under Aluminium Stress

Science.gov (United States)

Qian, Lianwen; Li, Qingbiao; Sun, Jingwei; Feng, Ying

2018-01-01

Aluminium-enriched acid red soils in South China easily cause aluminium toxicity to plants, but biochip can improve soils and eliminate soil contaminations. In this project, biochip was used in potted plant control test to study the effect of biochip on plant growth in soil under acid aluminium stress and the migration and conversion of aluminium in plant-soil system. The fin dings show that the application of biochip increases the pH value of soil under aluminium stress significantly, changes the existing form of aluminium ion in soil, reduces the plants’ absorption of aluminium, and alleviates the aluminium toxicity to plants, but too much biochip may inhibit the growth of plants. In this case, further study should be carried out as regards the volume and way of biochip input in practical applications as well as the timeliness of aluminium toxicity removal.

Confined recrystallization of high-purity aluminium during accumulative roll bonding of aluminium laminates

International Nuclear Information System (INIS)

Chekhonin, Paul; Beausir, Benoît; Scharnweber, Juliane; Oertel, Carl-Georg; Hausöl, Tina; Höppel, Heinz Werner; Brokmeier, Heinz-Günter; Skrotzki, Werner

2012-01-01

Aluminium laminates consisting of high-purity aluminium and commercially pure aluminium have been produced by accumulative roll bonding (ARB) at ambient temperature for up to 10 cycles. To study the microstructure and texture development of the high-purity aluminium layers with regard to the shrinking layer thickness during ARB, microstructure and texture investigations were carried out by electron backscatter diffraction and neutron and X-ray diffraction, respectively. While the commercially pure aluminium layers develop an ultrafine-grained microstructure, partial discontinuous recrystallization occurs in the high-purity layers. The texture of the high-purity layers mainly consists of Cube and “Tilted Cube” (tilted with respect to the transverse direction) components. The experimental results are discussed with respect to confined recrystallization in the ARB aluminium laminates.

Alloys of uranium and aluminium with low aluminium content

International Nuclear Information System (INIS)

Cabane, G.; Englander, M.; Lehmann, J.

1955-01-01

Uranium, as obtained after spinning in phase γ, presents an heterogeneous structure with large size grains. The anisotropic structure of the metal leads to an important buckling and surface distortion of the fuel slug which is incompatible with its tubular cladding for nuclear fuel uses. Different treatments have been made to obtain an isotropic structure presenting high thermal stability (laminating, hammering and spinning in phase α) without success. Alloys of uranium and aluminium with low aluminium content present important advantage in respect of non allied uranium. The introduction of aluminium in the form of intermetallic compound (UAl 2 ) gives a better resistance to thermal fatigue. Alloys obtained from raw casting present an improved buckling and surface distortion in respect of pure uranium. This improvement is obtained with uranium containing between 0,15 and 0,5 % of aluminium. An even more improvement in thermal stability is obtained by thermal treatments of these alloys. These new characteristics are explained by the fine dispersion of the UAl 2 particles in uranium. The results after treatments obtained from an alloy slug containing 0,4 % of aluminium show no buckling or surface distortion and no elongation. (M.P.)

Phase transformation of aluminium hydroxide to aα- alumina prepared from different aluminium salts

International Nuclear Information System (INIS)

Masliana Muslimin; Meor Yusoff Meor Sulaiman

2006-01-01

The study intends to look at the most suitable aluminium salt to produce a single-phase a-alumina by the hydrothermal method. In the process to produce alumina from the calcination of aluminium hydroxide (Al(OH) 3 ), three different aluminium salts namely aluminium sulfate (Al 2 (SO 4) 2), aluminium nitrate (A(NO 3 ) 3 ) and aluminium chloride (AlCl 3 ) were tried. The process involved the used of NH 4 OH as the precipitating medium. Aluminium hydroxide produced from each of these salts were characterised by x-ray diffraction (XRD) technique to identity the crystalline phase. Aluminium hydroxide produced by all the different aluminium salts is present as boehmite or pseudo-boehmite phase. Aluminium hydroxide produced from Al 2 (SO) 2 , Al(NO) 3 and AlCl 3 shows the transformation of the boehmite phase to a α-alumina phase at 500 0 C. On further heating, the α-alumina continuously formed at 800 o C followed soon at 1000 o C. But for the Al(NO3) 3 salts a different phase transitions occurs on heating especially at 1000 o C. Here it was observed not a single alumina phase is presence but the presence of both α and γ--alumina phases. At 1300 o C, the single α-alumina phase was formed. The study concluded that aluminium sulphate is recommended in order to obtain a single-phase α-alumina with the required characteristics. (Author)

Coprecipitation of yttrium and aluminium hydroxide for preparation of yttrium aluminium garnet

NARCIS (Netherlands)

Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.

1990-01-01

Coprecipitation of yttrium and aluminium hydroxide for the preparation of pure yttrium aluminium garnet (YAG) powder with small grain size is the subject of this study. Starting materials are sulphates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3Al5O12), the pH during flocculation

Distribution of the ore elements in ore bodies of the Zapolyarnoe field (Kola Peninsula

Directory of Open Access Journals (Sweden)

D. V. Taymasov

2017-12-01

Full Text Available The author conducted studies of the chemical zonality of ore deposits of all types for the sulfide-copper-nickel deposit Zapolyarnoe. Within the deposit of sulfide-copper-nickel ores Zapolyarnoe are the following industrial types of ores: rich interspersed ores, which are interspersed mineralization in peridotites; brecciated ores formed by detrital material; poor interspersed ores characterized by vein-interspersed mineralization; solid ores in a form of massive sulphide emissions. This work is based on operational and detailed exploration data. The author sorted samples according to the types of ores. Using the results, the author derived regression lines and their formulas to rectilinear dependencies. Analysis of the graphs showed that for all types of ores the dependences of copper and cobalt content on nickel content are direct, but at that, in thick-interspersed and brecciated types they are similar, and in scattered-interspersed they differ significantly. It becomes clear that correlation of copper and nickel in ore body depends on the scattered-interspersed ores, whereas the correlation of cobalt and nickel is determined mainly by thick-interspersed and brecciated ores. Dependencies between nickel, copper and cobalt in ores change when concentration of nickel in the ore changes. The graphs also show that the ratio of Ni/Cu in breccias and scattered-interspersed ores, as well as in near-ore metaperidotites, is almost constant at different nickel concentrations, on average 2:1.5 and 1, respectively. Thick- interspersed ores show the tendency towards an increase in the ratio with an increase in nickel content. The Ni/Co ratio increases with an increase of Ni concentration in all types of ores. In rich ores, growth occurs along a stepped curve, and in breccias – rectilinearly. Thus, the analysis of distribution of ore elements in ore bodies indicates a complex heterogeneous composition of sulphide mineralizations in different types of ores

Uranium ores

International Nuclear Information System (INIS)

Poty, B.; Roux, J.

1998-01-01

The processing of uranium ores for uranium extraction and concentration is not much different than the processing of other metallic ores. However, thanks to its radioactive property, the prospecting of uranium ores can be performed using geophysical methods. Surface and sub-surface detection methods are a combination of radioactive measurement methods (radium, radon etc..) and classical mining and petroleum prospecting methods. Worldwide uranium prospecting has been more or less active during the last 50 years, but the rise of raw material and energy prices between 1970 and 1980 has incited several countries to develop their nuclear industry in order to diversify their resources and improve their energy independence. The result is a considerable increase of nuclear fuels demand between 1980 and 1990. This paper describes successively: the uranium prospecting methods (direct, indirect and methodology), the uranium deposits (economical definition, uranium ores, and deposits), the exploitation of uranium ores (use of radioactivity, radioprotection, effluents), the worldwide uranium resources (definition of the different categories and present day state of worldwide resources). (J.S.)

Toxicity of aluminium on five aquatic invertebrates; Aluminiums toksisitet paa 5 akvatiske invertebrater

Energy Technology Data Exchange (ETDEWEB)

Moe, J [Oslo Univ. (Norway)

1996-01-01

The conference paper deals with the experiments done by investigating the effects from the toxicity of aluminium on aquatic invertebrates. The aim of the experiments was to compare the toxicity of unstable aluminium compounds with stable forms of aluminium. 8 refs., 2 figs., 2 tabs.

Effect of Sintering Temperature on the Properties of Aluminium-Aluminium Oxide Composite Materials

Directory of Open Access Journals (Sweden)

Dewan Muhammad Nuruzzaman

2016-12-01

Full Text Available In this study, aluminium-aluminium oxide (Al-Al2O3 metal matrix composites of different weight percentage reinforcements of aluminium oxide were processed at different sintering temperatures. In order to prepare these composite specimens, conventional powder metallurgy (PM method was used. Three types specimens of different compositions such as 95%Al+5%Al2O3, 90%Al+10%Al2O3 and 85%Al+15%Al2O3 were prepared under 20 Ton compaction load. Then, all the specimens were sintered in a furnace at two different temperatures 550oC and 580oC. In each sintering process, two different heating cycles were used. After the sintering process, it was observed that undistorted flat specimens were successfully prepared for all the compositions. The effects of sintering temperature and weight fraction of aluminium oxide particulates on the density, hardness and microstructure of Al-Al2O3 composites were observed. It was found that density and hardness of the composite specimens were significantly influenced by sintering temperature and percentage aluminium oxide reinforcement. Furthermore, optical microscopy revealed that almost uniform distribution of aluminium oxide reinforcement within the aluminium matrix was achieved.

Dispersion strengthening of aluminium-aluminium-oxide products

DEFF Research Database (Denmark)

Hansen, Niels

1970-01-01

The true stress-true strain curves at room temperature and at 400°C were determined for various types of aluminium-aluminium-oxide products containing from 0.2 to 4.7 weight per cent of aluminium oxide. The effect of particles on the initial flow stress and the flow stress for 0.2% offset at room...... temperature and at 400°C is in agreement with Orowan's theory. The increase in flow stress at room temperature for strain values below 3 per cent was related to the plastic strain by the equation σ-σoy=k1ε 1/2, where σoy is the initial flow stress and where k1 increases for increasing volume fraction...... and decreasing particle size of the dispersed particles. A general expression for k1 was derived for the relationship between the dislocation density and the strain in dispersion-strengthened products...

The prophylactic reduction of aluminium intake.

Science.gov (United States)

Lione, A

1983-02-01

The use of modern analytical methods has demonstrated that aluminium salts can be absorbed from the gut and concentrated in various human tissues, including bone, the parathyroids and brain. The neurotoxicity of aluminium has been extensively characterized in rabbits and cats, and high concentrations of aluminium have been detected in the brain tissue of patients with Alzheimer's disease. Various reports have suggested that high aluminium intakes may be harmful to some patients with bone disease or renal impairment. Fatal aluminium-induced neuropathies have been reported in patients on renal dialysis. Since there are no demonstrable consequences of aluminium deprivation, the prophylactic reduction of aluminium intake by many patients would appear prudent. In this report, the major sources of aluminium in foods and non-prescription drugs are summarized and alternative products are described. The most common foods that contain substantial amounts of aluminium-containing additives include some processed cheeses, baking powders, cake mixes, frozen doughs, pancake mixes, self-raising flours and pickled vegetables. The aluminium-containing non-prescription drugs include some antacids, buffered aspirins, antidiarrhoeal products, douches and haemorrhoidal medications. The advisability of recommending a low aluminium diet for geriatric patients is discussed in detail.

Study on the determination of ore-formation age of primary gold ore

International Nuclear Information System (INIS)

Ying Junlong; Zhao Puyun; Guo Hong

1997-01-01

The accurate determination of gold ore-formation age and ore-source isotope composition are of important significance in the research on gold geology and prospecting. According to the summary of three year indoor and field work, the ore-formation ages and isotope compositions of some typical gold deposits were obtained: The age of gold ore of the Wuhuaaobao deposit in geo-syncline region north to the north margin of North-China paleo-land is 130-120 Ma corresponding to the Late-orogenic stage. The ore-formation age of the Saiwusu gold deposit in the southern platform region is 211 +- 15 Ma, recycling reworking of the old-land. The Hougou-Huangtuliang gold deposit located in the middle of the platform region is 243 +- 7 Ma old attributed to the regeneration ore-formation on the old-land. the age of Jiaojia-Rushan gold deposit in Eastern Shandong is 122.7 +- 3.4 Ma and 128 +- 23 Ma belonging to Yanshanian stage. The Babaoshan gold-silver deposit in Cathaysian old-land is 140 +- 5 Ma old originated from volcanic hydrothermal ore-formation

Investigation of the aluminium-aluminium oxide reversible transformation as observed by hot stage electron microscopy.

Science.gov (United States)

Grove, C. A.; Judd, G.; Ansell, G. S.

1972-01-01

Thin foils of high purity aluminium and an Al-Al2O3 SAP type of alloy were oxidised in a specially designed hot stage specimen chamber in an electron microscope. Below 450 C, amorphous aluminium oxide formed on the foil surface and was first detectable at foil edges, holes, and pits. Islands of aluminium then nucleated in this amorphous oxide. The aluminium islands displayed either a lateral growth with eventual coalescence with other islands, or a reoxidation process which caused the islands to disappear. The aluminium island formation was determined to be related to the presence of the electron beam. A mechanism based upon electron charging due to the electron beam was proposed to explain the nucleation, growth, coalescence, disappearance, and geometry of the aluminium islands.

TEM investigation of aluminium containing precipitates in high aluminium doped silicon carbide

International Nuclear Information System (INIS)

Wong-Leung, J.; FitzGerald, J.D.

2002-01-01

Full text: Silicon carbide is a promising semiconductor material for applications in high temperature and high power devices. The successful growth of good quality epilayers in this material has enhanced its potential for device applications. As a novel semiconductor material, there is a need for studying its basic physical properties and the role of dopants in this material. In this study, silicon carbide epilayers were grown on 4H-SiC wafers of (0001) orientation with a miscut angle of 8 deg at a temperature of 1550 deg C. The epilayers contained regions of high aluminium doping well above the solubility of aluminium in silicon carbide. High temperature annealing of this material resulted in the precipitation of aluminium in the wafers. The samples were analysed by secondary ion mass spectrometry and transmission electron microscopy. Selected area diffraction studies show the presence of aluminium carbide and aluminium silicon carbide phases. Copyright (2002) Australian Society for Electron Microscopy Inc

Analysis of aluminium in rat following administration of allergen immunotherapy using either aluminium or microcrystalline-tyrosine-based adjuvants.

Science.gov (United States)

McDougall, Stuart A; Heath, Matthew D; Kramer, Matthias F; Skinner, Murray A

2016-03-01

Investigation into the absorption, distribution and elimination of aluminium in rat after subcutaneous aluminium adjuvant formulation administration using ICP-MS is described. Assays were verified under the principles of a tiered approach. There was no evidence of systemic exposure of aluminium, in brain or in kidney. Extensive and persistent retention of aluminium at the dose site was observed for at least 180 days after administration. This is the first published work that has quantified aluminium adjuvant retention based on the quantity of aluminium delivered in a typical allergy immunotherapy course. The results indicate that the repeated administration of aluminium-containing adjuvants will likely contribute directly and significantly to an individual's body burden of aluminium.

TITANIUM CARBON ALUMINIUM : A NOVEL GRAIN REFINER FOR ALUMINIUM-LITHIUM ALLOYS

OpenAIRE

Birch , M.; Cowell , A.

1987-01-01

This work explores the possibility of achieving grain size control in aluminium-lithium alloys with the titanium carbon aluminium (TiCAl) master alloys invented at the Technical University of Berlin and developed by London and Scandinavian Metallurgical Co Ltd (LSM). Grain refining tests were conducted on a single batch of 8090 alloy using addition rates of 0.2wt% and 0.4wt% of TiCAl and 3/1 titanium boron aluminium (TiBAl). Other tests using 0.4wt% of binary TiAl gave poor results, showing t...

Aluminium in Infrastructures

NARCIS (Netherlands)

Maljaars, J.

2016-01-01

Aluminium alloys are used in infrastructures such as pedestrian bridges or parts of it such as handrail. This paper demonstrates that aluminium alloys are in principle also suited for heavy loaded structures, such as decks of traffic bridges and helicopter landing platforms. Recent developments in

Formation of aluminium nitride and segregation of Cu impurity atoms in aluminium implanted by high dose nitrogen ions

International Nuclear Information System (INIS)

Lin Chenglu; Hemment, P.L.F.; Li Jinhua; Zou Shichang

1994-01-01

Aluminium films with a thickness of 7000 A (containing 0.85% copper) were deposited on silicon substrates. 400 keV N 2 + or 350 keV N + ions were implanted into the aluminium films or at the interface between the aluminium and silicon, respectively. Automatic spreading resistance (ASR), Fourier transform infrared spectroscopy (FTIR) and Rutherford backscattering (RBS) and channelling were used to characterize the formation of aluminium nitride and the depth distribution of the Cu impurity in the aluminium films after ion implantation and post-annealing. The formation of a stoichiometric AlN layer with high resistance was evident from ASR, RBS analysis and FTIR measurements by the presence of the absorption band at 650 cm -1 . When the implanted nitrogen is near the interface between the aluminium and silicon, a multilayer structure can be obtained, which consists of aluminium, aluminium nitride and the silicon substrate. Cu, which is a background impurity in the deposited aluminium films, segregated into the synthesised aluminium nitride during high dose nitrogen ion implantation. This is due to irradiation-induced segregation during ion implantation. (orig.)

Ion nitriding of aluminium

International Nuclear Information System (INIS)

Fitz, T.

2002-09-01

The present study is devoted to the investigation of the mechanism of aluminium nitriding by a technique that employs implantation of low-energy nitrogen ions and diffusional transport of atoms. The nitriding of aluminium is investigated, because this is a method for surface modification of aluminium and has a potential for application in a broad spectrum of fields such as automobile, marine, aviation, space technologies, etc. However, at present nitriding of aluminium does not find any large scale industrial application, due to problems in the formation of stoichiometric aluminium nitride layers with a sufficient thickness and good quality. For the purposes of this study, ion nitriding is chosen, as an ion beam method with the advantage of good and independent control over the process parameters, which thus can be related uniquely to the physical properties of the resulting layers. Moreover, ion nitriding has a close similarity to plasma nitriding and plasma immersion ion implantation, which are methods with a potential for industrial application. (orig.)

Variation in aluminium patch test reactivity over time.

Science.gov (United States)

Siemund, Ingrid; Mowitz, Martin; Zimerson, Erik; Bruze, Magnus; Hindsén, Monica

2017-11-01

Contact allergy to aluminium has been reported more frequently in recent years. It has been pointed out that positive patch test reactions to aluminium may not be reproducible on retesting. To investigate possible variations in patch test reactivity to aluminium over time. Twenty-one adults, who had previously reacted positively to aluminium, were patch tested with equimolar dilution series in pet. of aluminium chloride hexahydrate and aluminium lactate, four times over a period of 8 months. Thirty-six of 84 (43%) serial dilution tests with aluminium chloride hexahydrate and 49 of 84 (58%) serial dilution tests with aluminium lactate gave negative results. The range of reactivity varied between a negative reaction to aluminium chloride hexahydrate at 10% and/or to aluminium lactate at 12%, and a positive reaction to aluminium chloride hexahydrate at 0.1% and/or to aluminium lactate at 0.12%. The highest individual difference in test reactivity noticed was 320-fold when the two most divergent minimal eliciting concentrations were compared. The patch test reactivity to aluminium varies over time. Aluminium-allergic individuals may have false-negative reactions. Therefore, retesting with aluminium should be considered when there is a strong suspicion of aluminium contact allergy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Recovery in aluminium

DEFF Research Database (Denmark)

Gundlach, Carsten

2006-01-01

In the present thesis the development of a unique experimental method for volume characterisation of individual embedded crystallites down to a radius of 150 nm is presented. This method is applied to in-situ studies of recovery in aluminium. The method is an extension of 3DXRD microscopy, an X...... are represented as strings. To identify the strings a combination of a 5D connected component type algorithm and multi-peak fitting was found to be superior. The first use of the method was a study of recovery of a deformed aluminium alloy (AA1050). The aluminium alloy was deformed by cold rolling to a thickness...

Energy, metals, and ores in France in 1975

Energy Technology Data Exchange (ETDEWEB)

1976-01-01

As is customary every year, this number of Annales des Mines gives a complete synopsis of the problems concerning energy (coal, hydrocarbons, gas, electricity, uranium), metals (aluminium, copper, tin, steel, nickel, lead, zinc) and ores (chrome, manganese, phosphate, potash, sulphur, fluorspar). This synopsis mainly concerns France, but the problems are viewed within a worldwide framework. The year 1975 was characterized by a severe crisis of world economy: fall of the gross national product, unemployment, and inflation. In France, industrial production decreased by 7%. For the first time since the war, the energy consumption of the ultimate users was reduced. This decrease in consumption affected only the solid mineral fuels (-21%) and petroleum products (-6.7%). On the contrary the consumption of electricity and particularly of gas increased (respectively, 0.4% and 7.9%). For the first time since 1964, French production of solid fuels did not decrease, but, on the other hand, consumption was appreciably lower. The unfavourable prospects of the oil market were responsible for the cancellation of all projects for the extension of the refineries. The growth of nuclear energy production (+26.8% compared to 1974) together with a normal coefficient of water-power electricity resulted in a peak production of primary electricity equal in actual fact to that of solid fuels. There was a 20% drop of the French steel production with a 15% lower consumption; a decrease of bauxite production, only a slight drop in aluminium production (-2.7%), a drop in the exportation of nickel to Japan (-26%), and an important decrease in the consumption of phosphates (-30%) and potash.

Ore sorting using natural gamma radiation

International Nuclear Information System (INIS)

Clark, G.J.; Dickson, B.L.; Gray, F.E.

1980-01-01

A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

Internal friction in iron-aluminium alloys having a high aluminium content

International Nuclear Information System (INIS)

Hillairet, J.; Delaplace, J.; Silvent, A.

1966-01-01

By using a torsion pendulum to measure the internal friction of iron-aluminium alloys containing between 25 and 50 atom per cent of aluminium, it has been possible to show the existence of three damping peaks due to interstitial carbon. Their evolution is followed as a function of the carbon content, of the thermal treatment and of the aluminium content. A model based on the preferential occupation of tetrahedral sites is proposed as an interpretation of the results. A study of the Zener peak in these substitution alloys shows also that a part of the short distance disorder existing at high temperatures can be preserved by quenching. (author) [fr

Studies on uranium ore processing

International Nuclear Information System (INIS)

Kim, C.H.; Park, S.W.; Lim, J.K.; Chung, M.K.

1981-01-01

Chemical and chemical engineering techniques of the uranium ore processing established by France COGEMA (Compagnie Generale des Matieres Nucleaires) have been comprehensively reviewed in preparation for successful test operation of the pilot plant to be completed by the end of 1981. It was found that the amount of sulfuric acid (75 Kg/t, ore) and sodium chlorate (2.5 Kg/t, ore) recommended by COGEMA should be increased up to 100 Kg/t, ore and 10 Kg/t, ore respectively to obtain satisfactory leach of uranium for some ore samples produced at the different pits of Goesan uranium mine. Conditions of the other processes such as solvent extraction, stripping, and precipitation of yellow cake were generally agreed with the results of intensive studies done by this laboratory

The determination of trace oxygen in aluminium and aluminium-silicon alloy by helium-3 activation analysis

International Nuclear Information System (INIS)

Vandecasteele, C.; Goethals, P.; Kieffer, R.; Hoste, J.

1975-01-01

The determination of oxygen in aluminium and aluminium-silicon alloy by helium-3 activation is studied. The 18 F formed from oxygen is separated by distillation followed by precipitation of leadfluorochloride. The chemical yield is determined by activation in an isotopic neutron source. Concentrations of resp. 27 and 64 ng.g -1 with a precision for a single determination of resp. 30 and 13% are found in 99.5% aluminium and in aluminium-silicon (3%) alloy. (author)

Roll bonding of strained aluminium

DEFF Research Database (Denmark)

Staun, Jakob M.

2003-01-01

This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

New interpretation of the dominant ore-controlling factor of the uranium ore field No. 322

International Nuclear Information System (INIS)

Liu Xiang; Yang Chongqiu

1996-01-01

The NE-trending fault structures in ore field NO. 322 are characterized by compress-shearing, left-Lateral left-slipping, having an obvious control over the Localisation of the ore field No. 322, and are the dominant ore-controlling factor of the ore field NO.322. Resulting from the sinistral displacement of the NE-trending fault, there is a pull-apart basin in the Feng Zhou area. The formation and evolution of the NE-trending fault zone and the Feng Zhou basin control the formation of uranium deposits of ore field No. 322

Aluminium in foodstuffs and diets in Sweden.

Science.gov (United States)

Jorhem, L; Haegglund, G

1992-01-01

The levels of aluminium have been determined in a number of individual foodstuffs on the Swedish market and in 24 h duplicate diets collected by women living in the Stockholm area. The results show that the levels in most foods are very low and that the level in vegetables can vary by a factor 10. Beverages from aluminium cans were found to have aluminium levels not markedly different from those in glass bottles. Based on the results of the analysis of individual foods, the average Swedish daily diet was calculated to contain about 0.6 mg aluminium, whereas the mean content of the collected duplicate diets was 13 mg. A cake made from a mix containing aluminium phosphate in the baking soda was identified as the most important contributor of aluminium to the duplicate diets. Tea and aluminium utensils were estimated to increase the aluminium content of the diets by approximately 4 and 2 mg/day, respectively. The results also indicate that a considerable amount of aluminium must be introduced from other sources.

Constructions of aluminium electrolytic cells

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter of monograph is devoted to constructions of aluminium electrolytic cells. Therefore, the general characteristic and classification of aluminium electrolytic cells was considered. The anode and cathode structure was studied. The lining of cathode casing, the process of collection of anode gases, electrolytic cell cover, and electrical insulation was studied as well. The installation and dismantling of aluminium electrolytic cells was described.

Determination of aluminium in groundwater samples by GF-AAS, ICP-AES, ICP-MS and modelling of inorganic aluminium complexes.

Science.gov (United States)

Frankowski, Marcin; Zioła-Frankowska, Anetta; Kurzyca, Iwona; Novotný, Karel; Vaculovič, Tomas; Kanický, Viktor; Siepak, Marcin; Siepak, Jerzy

2011-11-01

The paper presents the results of aluminium determinations in ground water samples of the Miocene aquifer from the area of the city of Poznań (Poland). The determined aluminium content amounted from aluminium determinations were performed using three analytical techniques: graphite furnace atomic absorption spectrometry (GF-AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS). The results of aluminium determinations in groundwater samples for particular analytical techniques were compared. The results were used to identify the ascent of ground water from the Mesozoic aquifer to the Miocene aquifer in the area of the fault graben. Using the Mineql+ program, the modelling of the occurrence of aluminium and the following aluminium complexes: hydroxy, with fluorides and sulphates was performed. The paper presents the results of aluminium determinations in ground water using different analytical techniques as well as the chemical modelling in the Mineql+ program, which was performed for the first time and which enabled the identification of aluminium complexes in the investigated samples. The study confirms the occurrence of aluminium hydroxy complexes and aluminium fluoride complexes in the analysed groundwater samples. Despite the dominance of sulphates and organic matter in the sample, major participation of the complexes with these ligands was not stated based on the modelling.

[Association between serum aluminium level and methylation of amyloid precursor protein gene in workers engaged in aluminium electrolysis].

Science.gov (United States)

Yang, X J; Yuan, Y Z; Niu, Q

2016-04-20

To investigate the association between serum aluminium level and methylation of the promoter region of amyloid precursor protein (APP)gene in workers engaged in aluminium electrolysis. In 2012, 366 electrolysis workers in an aluminium factory were enrolled as exposure group (working years >10 and age >40 years)and divided into low-exposure group and high-exposure group based on the median serum aluminium level. Meanwhile, 102 workers in a cement plant not exposed to aluminium were enrolled as control group. Graphite furnace atomic absorption spectrometry was used to measure serum aluminium level, methylation specific PCR was used to measure the methylation rate of the promoter region of APP gene, and ELI-SA was used to measure the protein expression of APP in lymphocytes in peripheral blood. The exposure group had a significantly higher serum aluminium level than the control group (45.07 μg/L vs 30.51 μg/L, P0.05). The multivariate logistic regression analysis showed that with reference to the control group, low aluminium exposure (OR=1.86, 95% CI 1.67~3.52)and high aluminium exposure (OR=2.98, 95% CI 1.97~4.15)were risk factors for a reduced methylation rate of the promoter region of APP gene. Reduced methylation of the promoter region of APP gene may be associated with increased serum aluminium level, and downregulated methylation of the promoter region of APP gene may accelerate APP gene transcription.

Bumblebee pupae contain high levels of aluminium.

Science.gov (United States)

Exley, Christopher; Rotheray, Ellen; Goulson, David

2015-01-01

The causes of declines in bees and other pollinators remains an on-going debate. While recent attention has focussed upon pesticides, other environmental pollutants have largely been ignored. Aluminium is the most significant environmental contaminant of recent times and we speculated that it could be a factor in pollinator decline. Herein we have measured the content of aluminium in bumblebee pupae taken from naturally foraging colonies in the UK. Individual pupae were acid-digested in a microwave oven and their aluminium content determined using transversely heated graphite furnace atomic absorption spectrometry. Pupae were heavily contaminated with aluminium giving values between 13.4 and 193.4 μg/g dry wt. and a mean (SD) value of 51.0 (33.0) μg/g dry wt. for the 72 pupae tested. Mean aluminium content was shown to be a significant negative predictor of average pupal weight in colonies. While no other statistically significant relationships were found relating aluminium to bee or colony health, the actual content of aluminium in pupae are extremely high and demonstrate significant exposure to aluminium. Bees rely heavily on cognitive function and aluminium is a known neurotoxin with links, for example, to Alzheimer's disease in humans. The significant contamination of bumblebee pupae by aluminium raises the intriguing spectre of cognitive dysfunction playing a role in their population decline.

Long-term effects of aluminium dust inhalation.

Science.gov (United States)

Peters, Susan; Reid, Alison; Fritschi, Lin; de Klerk, Nicholas; Musk, A W Bill

2013-12-01

During the 1950s and 1960s, aluminium dust inhalation was used as a potential prophylaxis against silicosis in underground miners, including in Australia. We investigated the association between aluminium dust inhalation and cardiovascular, cerebrovascular and Alzheimer's diseases in a cohort of Australian male underground gold miners. We additionally looked at pneumoconiosis mortality to estimate the effect of the aluminium therapy. SMRs and 95% CI were calculated to compare mortality of the cohort members with that of the Western Australian male population (1961-2009). Internal comparisons on duration of aluminium dust inhalation were examined using Cox regression. Aluminium dust inhalation was reported for 647 out of 1894 underground gold miners. During 42 780 person-years of follow-up, 1577 deaths were observed. An indication of increased mortality of Alzheimer's disease among miners ever exposed to aluminium dust was found (SMR=1.38), although it was not statistically significant (95% CI 0.69 to 2.75). Rates for cardiovascular and cerebrovascular death were above population levels, but were similar for subjects with or without a history of aluminium dust inhalation. HRs suggested an increasing risk of cardiovascular disease with duration of aluminium dust inhalation (HR=1.02, 95% CI 1.00 to 1.04, per year of exposure). No difference in the association between duration of work underground and pneumoconiosis was observed between the groups with or without aluminium dust exposure. No protective effect against silicosis was observed from aluminium dust inhalation. Conversely, exposure to aluminium dust may possibly increase the risk of cardiovascular disease and dementia of the Alzheimer's type.

Inhalation of uranium ores

International Nuclear Information System (INIS)

Stuart, B.O.; Jackson, P.O.

1975-01-01

In previous studies the biological dispositions of individual long-lived alpha members of the uranium chain ( 238 U, 234 U and 230 Th) were determined during and following repeated inhalation exposures of rats to pitchblende (26 percent U 3 O 8 ) ore. Although finely dispersed ore in secular equilibrium was inhaled, 230 Th/ 234 U radioactivity ratios in the lungs rose from 1.0 to 2.5 during 8 weeks of exposures and increased to 9.2 by four months after cessation of exposures. Marked non-equilibrium levels were also found in the tracheobronchial lymph nodes, kidneys, liver, and femur. Daily exposures of beagle dogs to high levels of this ore for 8 days resulted in lung 230 Th/ 234 U ratios of >2.0. Daily exposures of dogs to lower levels (0.1 mg/1) for 6 months, with sacrifice 15 months later, resulted in lung and thoracic lymph node 230 Th/ 234 U ratios ranging from 3.6 to 9 and nearly 7, respectively. The lungs of hamsters exposed to carnotite (4 percent U 3 O 8 ) ore in current lifespan studies show 230 Th/ 234 U ratios as high as 2.0 during daily inhalation of this ore in secular equilibrium. Beagle dogs sacrificed after several years of daily inhalations of the same carnotite ore plus radon daughters also showed marked non-equilibrium ratios of 230 Th/ 234 U, ranging from 5.6 to 7.4 in lungs and 6.2 to 9.1 in thoracic lymph nodes. This pattern of higher retention of 230 Th than 234 U in lungs, thoracic lymph nodes, and other tissues is thus consistent for two types of uranium ore among several species and suggests a reevaluation of maximum permissible air concentrations of ore, currently based only on uranium content

Design and analysis of aluminium brdiges

NARCIS (Netherlands)

Soetens, F.; Straalen, IJ.J. van

2004-01-01

Applications of aluminium have grown considerably in building and civil engineering the last decade, which is due to various aspects: light weight, durability and maintenance, use of extrusions. The paper starts with a short history of aluminium bridges and then focuses on aluminium bridges in the

Ore sorting

International Nuclear Information System (INIS)

Hawkins, A.P.; Richards, A.W.

1982-01-01

In an ore sorting apparatus, ore particles are bombarded with neutrons in a chamber and sorted by detecting radiation emitted by isotopes of elements, such as gold, forming or contained in the particles, using detectors and selectively controlling fluid jets. The isotopes can be selectively recognised by their radiation characteristics. In an alternative embodiment, shorter life isotopes are formed by neutron bombardment and detection of radiation takes place immediately adjacent the region of bombardment

Recycling of aluminium swarf by direct incorporation in aluminium melts

OpenAIRE

Puga, Hélder; Barbosa, J.; Soares, Delfim; Silva, Filipe Samuel; Ribeiro, Carlos Silva

2009-01-01

The purpose of this work was to recover a standard AlSi12Cu1 alloy from machining chips inside the foundry plant, by using an environmentally friend technique to produce cast ingots with characteristics similar to those of the commercially available 2nd melt raw material. The recyclability of aluminium swarf using different melting techniques and the influence of chips preparation in the aluminium alloy recovery rate and dross production was experimentally studied and evaluated...

Irradiation damage in aluminium single crystals produced by 50-keV aluminium and copper ions

DEFF Research Database (Denmark)

Henriksen, L.; Johansen, A.; Koch, J.

1968-01-01

Aluminium single crystals, thin enough to be examined by electron microscopy, have been irradiated with 50-keV aluminium and copper ions. The irradiation fluxes were in the range 1011–1014 cm−2 s−1 and the doses were from 6 × 1012 to 6 × 1014 cm−2. Irradiation along either a or a direction produces...... rows of dislocation loops all lying parallel to one particular direction. If the aluminium target is quenched from 600 °C and annealed at room temperature prior to irradiation with aluminium ions, the rows of loops are suppressed. The amount of damage observed is considerably less than would...

Laser welding of aluminium alloys

OpenAIRE

Forsman, Tomas

2000-01-01

This thesis treats laser welding of aluminium alloys from a practical perspective with elements of mathematical analysis. The theoretical work has in all cases been verified experimentally. The aluminium alloys studied are from the 5xxx and 6xxx groups which are common for example in the automotive industry. Aluminium has many unique physical properties. The properties which more than others have been shown to influence the welding process is its high reflection, high thermal conductivity, lo...

Processing of low-grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1975-01-01

Four types of low grade ores are studied. Low grade ores which must be extracted because they are enclosed in a normal grade deposit. Heap leaching is the processing method which is largely used. It allows to obtain solutions or preconcentrates which may be delivered at the nearest plant. Normal grade ores contained in a low amplitude deposit which can be processed using leaching as far as the operation does not need any large expensive equipment. Medium grade ores in medium amplitude deposits to which a simplified conventional process can be applied using fast heap leaching. Low grade ores in large deposits. The processing possibilities leading to use in place leaching are explained. The operating conditions of the method are studied (leaching agent, preparation of the ore deposit to obtain a good tightness with regard to the hydrological system and to have a good contact between ore and reagent) [fr

Developments in the US aluminium recycling industry

Energy Technology Data Exchange (ETDEWEB)

Bolling, R N

1983-06-01

In the USA scrap recovery of aluminium has gained in importance since the war. Today its amounts to about 32% of total supply. On the other hand primary production in the US seems to have hardly any expansion possibilities. The development of the aluminium beverage can is the clearest example for recycling growth. The increased use of aluminium in passenger cars has led to very close technical and local relations of aluminium foundries and secondary smelters. The changing nature of the aluminium business caused by the growth of recycling should be recognized and made use of.

Process for the manufacture of plates containing neutron poison from aluminium and aluminium alloys

International Nuclear Information System (INIS)

Bauer, G.; Pollmann, E.; Srostlik, P.

1985-01-01

A process for guaranteeing sub-critical arrangements of nuclear fuel in tranport and/or storage containers is described, in which a homogeneous distribution of neutron poison in the aluminium matrix is guaranteed. A homogeneous mixture of aluminium powder and neutron poison powder is produced, this is pressed into plates in several stages, dried and made into hollow aluminium profiles of rectangular cross-section. The open ends of the hollow profile are then closed and this is rolled to the required dimension at 470-500 0 C. (orig./HP) [de

Chapter 1. Economic aspects of aluminium production

International Nuclear Information System (INIS)

Yanko, E.A.; Kabirov, Sh.O.; Safiev, Kh.; Azizov, B.S.; Mirpochaev, Kh.A.

2011-01-01

This article is devoted to economic aspects of aluminium production. Therefore, the perspectives of development of aluminium production, the base components of aluminium cost and economic security of enterprise are considered in this chapter.

Aluminium and nickel in human albumin solutions

DEFF Research Database (Denmark)

Gammelgaard, Bente; Sandberg, E

1989-01-01

Five different brands of commercially available human albumin solutions for infusion were analysed for their aluminium and nickel contents by atomic absorption spectrometry. The aluminium concentrations ranged from 12 micrograms/l to 1109 micrograms/l and the nickel concentrations ranged from 17...... micrograms/l to 77 micrograms/l. Examination of the aluminium and nickel contents of the constituents for the production of one brand showed too low levels to explain the final contamination of the product. By following the aluminium and nickel concentrations of the same brand during the production...... of a batch of albumin solution, filtration was shown to contribute to contamination, although the largest increase in aluminium as well as nickel concentrations appeared during the bulk concentrating process. To avoid health risks to certain patients, regulations should be established requiring aluminium...

Physicochemical aspects of decomposition of silica-alumina ores of argillites and green clays of Chashma-Sang Deposit of the Republic of Tajikistan by hydrochloric and nitric acids

International Nuclear Information System (INIS)

Kayumov, A.M.

2018-01-01

The purpose of work is to study the processes of decomposition of silica-alumina ores of argillites and green clays of Chashma-Sang Deposit of the Republic of Tajikistan by hydrochloric and nitric acids in temperature interval 20-98 deg C with the using of methods of selective extraction of valuable materials; elaboration of rational conditions of decomposition of raw material. Physicochemical properties of initial aluminium comprising ores, intermediate and final products of processing of argillites and green clays have been studied. Kinetic parameters of processes at acidic decomposition of argillites and green clays have been studied as well. The kinetic parameters of processes of decomposition of green clays and argillites by nitric and hydrochloric acids have been calculated. The flowsheet of complex processing of green clays and argillites of Chashma-Sang Deposit has been elaborated.

Aluminium beverage can recycling

Energy Technology Data Exchange (ETDEWEB)

Lewinski, A von

1985-08-01

Canned beverages have become a controversial issue in this era of ecological sensitivity. METALL has already discussed the problem of can recycling. The present article discusses the technical aspects of aluminium can recycling. Two further articles will follow on aluminium can recycling in North America and on the results of European pilot projects.

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

Ford, H.L.; Levine, N.M.; Risdon, A.R.

1975-01-01

A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

Photochemical preparation of aluminium oxide layers via vacuum ultraviolet irradiation of a polymeric hexanoato aluminium complex

International Nuclear Information System (INIS)

Wennrich, L.; Khalil, H.; Bundesmann, C.; Decker, U.; Gerlach, J.W.; Helmstedt, U.; Manova, D.; Naumov, S.; Prager, L.

2013-01-01

By means of photochemical conversion of thin layers of a polymeric hexanoato aluminium complex as the precursor, thin aluminium oxide layers were prepared onto silicon wafers. The precursor compound was synthesized and characterized by several analytical techniques like NMR, FTIR, XPS, ICP, and found to be a polymeric aluminium-containing coordination compound which has been proposed to be a hydroxo-bridged aluminium chain with pendant hexanoyl side-chains ascertained as catena-poly[{di(κ-O,O-hexanoato)aluminium}(μ-hydroxo)] (PHAH). Thin layers deposited from a solution of PHAH in toluene onto silicon wafers were irradiated using VUV radiation from a xenon excimer lamp. The layers were characterized by XPS, XRD, XRR, and spectroscopic ellipsometry. VUV radiation with a radiant exposure of E = 36 J cm −2 led to almost carbon-free amorphous layers with a composition close to that of alumina having a density of about 2.1 g cm −3 . Thus, using the example of a polymeric aluminium complex, the potential of the photochemical conversion of metal complexes into oxides could be shown as an alternative method, in addition to sol–gel techniques, for the generation of thin plane metal-oxide layers at normal temperature and pressure. Highlights: ► A polymeric aluminium complex was synthesized and characterized by NMR, FTIR, XPS and ICP. ► Thin layers of the compound were irradiated using vacuum-UV radiation and converted to AlO x . ► Quantum-chemical calculations explain the conversion mechanism.

Aluminium-27 n.m.r. studies of aluminium fluoro complexes in dichloromethane solution: evidence for tetrafluoroaluminate anion

International Nuclear Information System (INIS)

Colton, R.; Eller, P.G.

1989-01-01

Mixed aluminium chloro/fluoro anions are formed in dichloromethane solution by the interaction of AlCl 3 and [Ph 3 PhCH 2 P] [H 2 F 3 ]. Aluminium-27 n.m.r. studies are restricted to the stoichiometric ranges F/Al from 1:1 to 3:1 and F/Al>8:1. Between these limits rapid precipitation reactions occur. In the fluoride-rich stoichiometric range there is rapid exchange on the n.m.r. time scale between the aluminium fluoro anion and free fluoride, so that a direct identification of the species by the multiplicity of the resonance is not possible. Indirect evidence strongly suggests that the aluminium species is [AlF 4 ] - . In the F/Al stoichiometry range from 1:1 to 3:1 aluminium-27 resonances were observed for all the other possible [AlCl χ F 4-χ ] - species. Studies on the aluminium iodo/fluoro system support the identification of [AlF 4 ] - , but the system is labile and the mixed iodo/fluoro species undergo rapid disproportionation. 12 refs., 1 fig

Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

Directory of Open Access Journals (Sweden)

Wenguang Du

2017-01-01

Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

Effect of hydrogen on aluminium and aluminium alloys: A review

DEFF Research Database (Denmark)

Ambat, Rajan; Dwarakadasa, E.S.

1996-01-01

Susceptibility of aluminium and its alloys towards hydrogen embrittlement has been well established. Still a lot of confusion exists on the question of transport of hydrogen and its possible role in stress corrosion cracking. This paper reviews some of the fundamental properties of hydrogen...... in aluminium and its alloys and its effect on mechanical properties. The importance of hydrogen embrittlement over anodic dissolution to explain the stress corrosion cracking mechanism of these alloys is also examined in considerable detail. The various experimental findings concerning the link between...

Raw materials for aluminium production

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter of monograph is devoted to to raw materials which used in aluminium production. Therefore, the using of alumina, and fluoride salts in aluminium production was considered. The physical properties of alumina were studied.

Sampling of ore

International Nuclear Information System (INIS)

Boehme, R.C.; Nicholas, B.L.

1987-01-01

This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

Electron beam welding of aluminium components

International Nuclear Information System (INIS)

Maajid, Ali; Vadali, S.K.; Maury, D.K.

2015-01-01

Aluminium is one of the most widely used materials in industries like transportation, shipbuilding, manufacturing, aerospace, nuclear, etc. The challenges in joining of aluminium are distortion, cleanliness and quality. Main difficulties faced during fusion welding of aluminium components are removal of surface oxide layer, weld porosity, high heat input requirement, distortion, hot cracking, etc. Physical properties of aluminium such as its high thermal conductivity, high coefficient of thermal expansion, no change in colour at high temperature, large difference in the melting points of the metal and its oxide (∼ 1400 °C) compound the difficulties faced during welding. Gas Tungsten Arc Welding (GTAW), Gas Metal Arc Welding (GMAW), Plasma Arc Welding (PAW), etc are generally used in industries for fusion welding of aluminium alloys. However in case of thicker jobs the above processes are not suitable due to requirements of elaborate edge preparation, preheating of jobs, fixturing to prevent distortion, etc. Moreover, precise control over the heat input during welding and weld bead penetration is not possible with above processes. Further, if heat sensitive parts are located near the weld joint then high energy density beam welding process like Electron Beam Welding (EBW) is the best possible choice for aluminium welding.This paper discusses EB welding of aluminium components, typical geometry of components, selection/optimization of welding parameters, problems faced during standardization of welding and process parameters and their remedies etc.

Recovery of lithium from geothermal water by amorphous hydrous aluminium oxide

International Nuclear Information System (INIS)

Wada, Hideo; Kitamura, Takao; Ooi, Kenta; Katoh, Shunsaku

1984-01-01

Effects of chemical composition, temperature, and lithium concentration of geothermal water on lithium recovery by amorphous hydrous aluminium oxide (a-HAO) were investigated in order to evaluate the feasibility of this process. The results are summarized as follows: (1) Among various chemical consituents in geothermal water, silica interfered with the lithium adsorption. The lithium uptake decreased when silica concentration exceeded 73 mg/l under 100 mg/50 ml a-HAO to solution ratio. (2) The lithium uptake decreased with an increase of adsorption temperature and was not observed above 40 deg C. At higher temperature, the crystallization of a-HAO to bayerite occurred prior to lithium adsorption. (3) The lithium uptake increased with an increase of lithium concentration. Lithium uptake comparable with lithium contents in lithium ores was obtained at the lithium concentration of 30 mg/l at 20 deg C. These results show that a-HAO is applicable to collect lithium from geothermal water if silica can be removed before lithium adsorption. (author)

Chapter 2. Theoretical aspects of aluminium production

International Nuclear Information System (INIS)

Yanko, E.A.; Kabirov, Sh.O.; Safiev, Kh.; Azizov, B.S.; Mirpochaev, Kh.A.

2011-01-01

This article is devoted to theoretical aspects of aluminium production. Thus, the electrochemistry of electrolysis process, calculation of base industrial indicators of aluminium electrolytic cell, and processes occurring on anode and cathode were considered. Factors, which increase the current output and electrolytic cell productivity were studied. The side effects, including anode effect, sodium extraction on cathode, aluminium dissolution in the electrolyte, aluminium carbide formation, and influence of admixtures in the electrolyte were studied as well.

Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

International Nuclear Information System (INIS)

Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

2011-01-01

Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

Influence of acid/ore relation in the uranium-silicate ore treatment

International Nuclear Information System (INIS)

Antaki, C.; Cipriani, M.; Bruno, J.B.

1985-01-01

The estimation of acid addition effect (Kg of H 2 SO 4 /t of ore) in uranium extraction from an uranium-silicate ore, with a view to the control of silica concentration in leach under 0,6 g/l is presented. The analysis was effected based on bench-scale tests, with different quantities of sulfuric acid addition. (Author) [pt

Processing of low grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1978-10-01

Four types of low-grade ores are studied: (1) Low-grade ores that must be extracted because they are enclosed in a normal-grade deposit. Heap leaching is the processing method which is largely used. (2) Normal-grade ores contained in low-amplitude deposits. They can be processed using in-place leaching as far as the operation does not need any large and expensive equipment. (3) Medium-grade ores in medium-amplitude deposits. A simplified conventional process can be applied using fast heap leaching. (4) Low-grade ores in large deposits. The report explains processing possibilities leading in most cases to the use of in-place leaching. The operating conditions of this method are laid out, especially the selection of the leaching agents and the preparation of the ore deposit

High-rate behaviour of iron ore pellet

Science.gov (United States)

Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

2015-09-01

Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

Studies on uranium ore processing

International Nuclear Information System (INIS)

Suh, I.S.; Chun, J.K.; Park, S.W.; Choi, S.J.; Lee, C.H.; Chung, M.K.; Lim, J.K.

1983-01-01

For the exploitation of domestic uranium ore deposit, comprehensive studies on uranium ore processing of the Geum-San pit ore are carried out. Physical and chemical characteristics of the Geum-San ore are similar to those of Goe-San ore and the physical beneficiation could not be applicable. Optimum operating conditions such as uranium leaching, solid-liquid separation, solvent extraction and precipitation of yellow cake are found out and the results are confirmed by the continous operation of the micro-plant with the capacity of 50Kg, ore/day. In order to improve the process of ore milling pilot plant installed recently, the feasibility of raffinate-recycle and the precipitation methods of yellow cake are intensively examined. It was suggested that the raffinate-recycle in the leaching of filtering stage could be reduced the environmental contamination and the peroxide precipitation technique was applicable to improve the purity of yellow cake. The mechanism and conditions the third phase formation are thoroughly studied and confirmed by chemical analysis of the third phase actually formed during the operation of pilot plant. The major constituents of the third phase are polyanions such as PMosub(12)Osub(40)sup(3-) or SiMosub(12)Osub(40)sup(4-). And the formation of these polyanions could be reduced by the control of redox potential and the addition of modifier. (Author)

Aluminium in brain tissue in familial Alzheimer's disease.

Science.gov (United States)

Mirza, Ambreen; King, Andrew; Troakes, Claire; Exley, Christopher

2017-03-01

The genetic predispositions which describe a diagnosis of familial Alzheimer's disease can be considered as cornerstones of the amyloid cascade hypothesis. Essentially they place the expression and metabolism of the amyloid precursor protein as the main tenet of disease aetiology. However, we do not know the cause of Alzheimer's disease and environmental factors may yet be shown to contribute towards its onset and progression. One such environmental factor is human exposure to aluminium and aluminium has been shown to be present in brain tissue in sporadic Alzheimer's disease. We have made the first ever measurements of aluminium in brain tissue from 12 donors diagnosed with familial Alzheimer's disease. The concentrations of aluminium were extremely high, for example, there were values in excess of 10μg/g tissue dry wt. in 5 of the 12 individuals. Overall, the concentrations were higher than all previous measurements of brain aluminium except cases of known aluminium-induced encephalopathy. We have supported our quantitative analyses using a novel method of aluminium-selective fluorescence microscopy to visualise aluminium in all lobes of every brain investigated. The unique quantitative data and the stunning images of aluminium in familial Alzheimer's disease brain tissue raise the spectre of aluminium's role in this devastating disease. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Recent developments in advanced aircraft aluminium alloys

International Nuclear Information System (INIS)

Dursun, Tolga; Soutis, Costas

2014-01-01

Highlights: • To compete with composites, performance of aluminium alloys should be increased. • Al–Li alloys have higher strength, fracture and fatigue/corrosion resistance. • Improvements of aerospace Al alloys are due to optimised solute content and ratios. • In selecting new materials, there should be no reduction in the level of safety. • The use of hybrid materials could provide additional opportunities for Al alloys. - Abstract: Aluminium alloys have been the primary material for the structural parts of aircraft for more than 80 years because of their well known performance, well established design methods, manufacturing and reliable inspection techniques. Nearly for a decade composites have started to be used more widely in large commercial jet airliners for the fuselage, wing as well as other structural components in place of aluminium alloys due their high specific properties, reduced weight, fatigue performance and corrosion resistance. Although the increased use of composite materials reduced the role of aluminium up to some extent, high strength aluminium alloys remain important in airframe construction. Aluminium is a relatively low cost, light weight metal that can be heat treated and loaded to relatively high level of stresses, and it is one of the most easily produced of the high performance materials, which results in lower manufacturing and maintenance costs. There have been important recent advances in aluminium aircraft alloys that can effectively compete with modern composite materials. This study covers latest developments in enhanced mechanical properties of aluminium alloys, and high performance joining techniques. The mechanical properties on newly developed 2000, 7000 series aluminium alloys and new generation Al–Li alloys are compared with the traditional aluminium alloys. The advantages and disadvantages of the joining methods, laser beam welding and friction stir welding, are also discussed

Toxicity of dissolved and precipitated aluminium to marine diatoms.

Science.gov (United States)

Gillmore, Megan L; Golding, Lisa A; Angel, Brad M; Adams, Merrin S; Jolley, Dianne F

2016-05-01

Localised aluminium contamination can lead to high concentrations in coastal waters, which have the potential for adverse effects on aquatic organisms. This research investigated the toxicity of 72-h exposures of aluminium to three marine diatoms (Ceratoneis closterium (formerly Nitzschia closterium), Minutocellus polymorphus and Phaeodactylum tricornutum) by measuring population growth rate inhibition and cell membrane damage (SYTOX Green) as endpoints. Toxicity was correlated to the time-averaged concentrations of different aluminium size-fractions, operationally defined as aluminium exposure varied between diatom species. C. closterium was the most sensitive species (10% inhibition of growth rate (72-h IC10) of 80 (55-100)μg Al/L (95% confidence limits)) while M. polymorphus (540 (460-600)μg Al/L) and P. tricornutum (2100 (2000-2200)μg Al/L) were less sensitive (based on measured total aluminium). Dissolved aluminium was the primary contributor to toxicity in C. closterium, while a combination of dissolved and precipitated aluminium forms contributed to toxicity in M. polymorphus. In contrast, aluminium toxicity to the most tolerant diatom P. tricornutum was due predominantly to precipitated aluminium. Preliminary investigations revealed the sensitivity of C. closterium and M. polymorphus to aluminium was influenced by initial cell density with aluminium toxicity significantly (paluminium toxicity to diatoms do not involve compromising the plasma membrane. These results indicate that marine diatoms have a broad range in sensitivity to aluminium with toxic mechanisms related to both dissolved and precipitated aluminium. Copyright © 2016 Elsevier B.V. All rights reserved.

Geochemical features of the ore-bearing medium in uranium deposits in the Khiagda ore field

Science.gov (United States)

Kochkin, B. T.; Solodov, I. N.; Ganina, N. I.; Rekun, M. L.; Tarasov, N. N.; Shugina, G. A.; Shulik, L. S.

2017-09-01

The Neogene uranium deposits of the Khiagda ore field (KOF) belong to the paleovalley variety of the hydrogene type and differ from other deposits of this genetic type in the geological and geochemical localization conditions. The contemporary hydrogeochemical setting and microbiological composition of ore-bearing medium are discussed. The redox potential of the medium (Eh is as low as-400 mV) is much lower than those established at other hydrogenic deposits, both ancient Late Mesozoic and young Late Alpine, studied with the same methods in Russia, Uzbekistan, and southern Kazakhstan. The pH of subsurface water (6.86-8.13) differs in significant fluctuations both between neighboring deposits and within individual ore lodes. Hydrogen-forming and denitrifying bacteria are predominant in microbiological populations, whereas sulfate-reducing bacteria are low-active. The consideration of these factors allowed us to describe the mechanism of uranium ore conservation as resulting from the development of the cryolithic zone, which isolates ore lodes from the effect of the external medium. Carbonated water supplied from the basement along fault zones also participates in the formation of the present-day hydrogeochemical setting. Based on the features of the ore-bearing medium, we propose a method of borehole in situ acid leaching to increase the efficiency of mining in the Khiagda ore field.

Lactobacillus plantarum CCFM639 alleviates aluminium toxicity.

Science.gov (United States)

Yu, Leilei; Zhai, Qixiao; Liu, Xiaoming; Wang, Gang; Zhang, Qiuxiang; Zhao, Jianxin; Narbad, Arjan; Zhang, Hao; Tian, Fengwei; Chen, Wei

2016-02-01

Aluminium (Al) is the most abundant metal in the earth's crust. Al exposure can cause a variety of adverse physiological effects in humans and animals. Our aim was to demonstrate that specific probiotic bacteria can play a special physiologically functional role in protection against Al toxicity in mice. Thirty strains of lactic acid bacteria (LAB) were tested for their aluminium-binding ability, aluminium tolerance, their antioxidative capacity, and their ability to survive the exposure to artificial gastrointestinal (GI) juices. Lactobacillus plantarum CCFM639 was selected for animal experiments because of its excellent performance in vitro. Forty mice were divided into four groups: control, Al only, Al plus CCFM639, and Al plus deferiprone (DFP). CCFM639 was administered at 10(9) CFU once daily for 10 days, followed by a single oral dose of aluminium chloride hexahydrate at 5.14 mg aluminium (LD50) for each mouse. The results showed that CCFM639 treatment led to a significant reduction in the mortality rates with corresponding decrease in intestinal aluminium absorption and in accumulation of aluminium in the tissues and amelioration of hepatic histopathological damage. This probiotic treatment also resulted in alleviation of hepatic, renal, and cerebral oxidative stress. The treatment of L. plantarum CCFM639 has potential as a therapeutic dietary strategy against acute aluminium toxicity.

Zeolitization at uranium ore manifestation

International Nuclear Information System (INIS)

Petrosyan, R.V.; Buntikova, A.F.

1981-01-01

The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

Ores and Climate Change - Primary Shareholders

Science.gov (United States)

Stein, Holly J.; Hannah, Judith L.

2015-04-01

Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

Structural evolution in nanoporous anodic aluminium oxide

International Nuclear Information System (INIS)

Rocca, Emmanuel; Vantelon, Delphine; Reguer, Solenn; Mirambet, François

2012-01-01

Nanoporous and self-organized layers of aluminium alloys are used in many applications as membranes, templates for nanometric objects or corrosion protection for aluminium alloys. The use of this nanometric structure widely remains empirical, especially in the case of very small pores ( 4 into AlO 6 cluster and a partial release of sulphate ions are an important chemical transformation of the amorphous structure. This structural transformation defines the chemistry (pH and surface charge) inside the nanopores, the ageing behaviour and the possible incorporation or diffusion of chemical species in the nanostructure. Highlights: ► Investigations of local chemical environment of aluminium atoms in anodic aluminium oxide. ► The oxide structure is constituted by 2/3 of aluminium in tetrahedral coordination 1/3 in octahedral coordination. ► In contact with water, AlO 4 clusters are transformed into AlO 6 cluster and the aluminium sulphate bonds are hydrolysed. ► These transformations induce a pH decrease inside the nanostructure.

Aluminium, gallium, indium and thallium

International Nuclear Information System (INIS)

Brown, Paul L.; Ekberg, Christian

2016-01-01

Aluminium can exist in a number of oxyhydroxide mineral phases including corundum, diaspore, boehmite and gibbsite. The stability constants at zero ionic strength reported for Al(OH) 3 (aq) vary linearly with respect to the inverse of absolute temperature. A full suite of thermodynamic parameters is available for all aluminium phases and hydrolysis species. Gallium hydrolyses to a greater extent than aluminium, with the onset of hydrolysis reactions occurring just above a pHof 1. In fact, even though aluminium has the smallest ionic radius of this series of metals, it has the weakest hydrolysis species and oxide/hydroxide phases.This is due to the presence of stabilising d-orbitals in the heavier metals, gallium, indium and thallium(III). There are few available data for the stability constants of indium(III) hydrolysis species. Of those that are available, the range in the proposed stability constants covers many orders of magnitude.

Ore loses and dilution of the ore vein no. 4 in the Zletovo mine, Republic of Macedonia

Directory of Open Access Journals (Sweden)

Bogatinovski Nikola L.

2017-01-01

Full Text Available Zletovo mines have a tradition of exploration and exploitation of vein lead-zinc ores for almost a century. Ore losses and dilutions have always been imperative in production since traditional old methods of mining and low-productivity mineralization are used. In conditions of classical and sub-level method excavations used, the calculated ore losses in ore vein No. 4 are 13.5%, while at the level of all excavations in the Zletovo mines dilution averages at 10%. Ore dilution is also an important technical parameter and several possible variants were calculated. When analyzing the dilution that occurs during the preparation of the sub-level corridor with parameters such: different drop angle (45-60o, constant thickness of 1.47 m as the average vein thickness in the calculated ore reserves, width of the sub-level corridor of 1.57 m or to the width of the ore vein No. 4 were added 10 cm (left and right to 5 cm as much as is taken in the calculation of the planned dilution and height of 2.5 m as suggested for this mining method, it can be noticed that the planned dilution during this method of mining ranges from 26.3% to 42.3%. In conditions of use of this underground method of excavation, parameters are selected that allow for the indicated lowering of the dilution. Namely, the thickness of the ore wire would be 1.47 m, the mining width would be 1.57 m, only 10 cm (left and right up to 5cm to the thickness of the ore vein will be added, the height difference between the consecutive levels would be 7.5 m, dip angle of 45 to 60°, and with the excavation the whole ore vein would be covered in height. On the basis of these parameters, models were prepared in which the ore vein would have a different dip angle, from which the values for the planned ore dilution ranged from 6.7 to 7.8%, which is significantly lower than the average dilution in the Zletovo Mine.

Challenges in LCA modelling of multiple loops for aluminium cans

DEFF Research Database (Denmark)

Niero, Monia; Olsen, Stig Irving

considered the case of closed-loop recycling for aluminium cans, where body and lid are different alloys, and discussed the abovementioned challenge. The Life Cycle Inventory (LCI) modelling of aluminium processes is traditionally based on a pure aluminium flow, therefore neglecting the presence of alloying...... elements. We included the effect of alloying elements on the LCA modelling of aluminium can recycling. First, we performed a mass balance of the main alloying elements (Mn, Fe, Si, Cu) in aluminium can recycling at increasing levels of recycling rate. The analysis distinguished between different aluminium...... packaging scrap sources (i.e. used beverage can and mixed aluminium packaging) to understand the limiting factors for multiple loop aluminium can recycling. Secondly, we performed a comparative LCA of aluminium can production and recycling in multiple loops considering the two aluminium packaging scrap...

Durability of bare and anodised aluminium in atmosphere of very different corrosivities I. Bare aluminium

International Nuclear Information System (INIS)

Gonzalez, J. A.; Escudero, E.; Lopez, V.; Simancas, J.; Morcillo, M.

2004-01-01

The behaviour of bare aluminium is studied in atmospheric exposure at 11 natural testing stations with salinity levels ranging between 2.1 and 684 mg Cl''- m''-2 d''-1. In atmospheres of low or moderate aggressivity aluminium behaves as a passive material, though the insignificant corrosion that is produced is sufficient to spoil its appearance. In contrast, at salinity levels of 50 mg Cl''- m''-2 ''-1 or above, aluminium is susceptible to pitting corrosion even in the first year of atmospheric exposure, or in the second year at salinities of ≤ 10 mg Cl''- m''-2 d''-1. For comparative purposes, results are included for aluminium protected with an anodic film of 28 μm thickness exposed at the same testing stations. A 28 μm anodic film, correctly sealed, prevents the risk of localised corrosion even in the most unfavourable situations. (Author) 23 refs

Fatigue test on aluminium bridges

NARCIS (Netherlands)

Maljaars, J.; Soetens, F.; Straalen, van IJ.J.

2005-01-01

Traffic bridges are subjected to variable loads and should therefore be checked on fatigue. Especially low weight materials, like aluminium, are sensitive to fatigue, because the variable load is a substantial part of the total load. This paper shows the structural design of an aluminium bridge

Fatal aluminium phosphide poisoning

Directory of Open Access Journals (Sweden)

Meena Mahesh Chand

2015-06-01

Full Text Available Aluminium phosphide (AlP is a cheap solid fumigant and a highly toxic pesticide which is commonly used for grain preservation. AlP has currently aroused interest with a rising number of cases in the past four decades due to increased use for agricultural and non-agricultural purposes. Its easy availability in the markets has increased also its misuse for committing suicide. Phosphine inhibits cellular oxygen utilization and can induce lipid peroxidation. Poisoning with AlP has often occurred in attempts to commit suicide, and that more often in adults than in teenagers. This is a case of suicidal consumption of aluminium phosphide by a 32-year-old young medical anesthetist. Toxicological analyses detected aluminium phosphide. We believe that free access of celphos tablets in grain markets should be prohibited by law.

Friction Welding of Aluminium and Aluminium Alloys with Steel

Directory of Open Access Journals (Sweden)

Andrzej Ambroziak

2014-01-01

Full Text Available The paper presents our actual knowledge and experience in joining dissimilar materials with the use of friction welding method. The joints of aluminium and aluminium alloys with the different types of steel were studied. The structural effects occurring during the welding process were described. The mechanical properties using, for example, (i microhardness measurements, (ii tensile tests, (iii bending tests, and (iv shearing tests were determined. In order to obtain high-quality joints the influence of different configurations of the process such as (i changing the geometry of bonding surface, (ii using the interlayer, or (iii heat treatment was analyzed. Finally, the issues related to the selection of optimal parameters of friction welding process were also investigated.

Aluminium cables in automotive applications : Prestudy of aluminium cable uses in Scania products&Failure analysis and evaluation

OpenAIRE

Man, Yu

2016-01-01

The increasing demand of light constructed vehicles as well as soaring price of copper metal owing to limited nature resources have been promoting the use of aluminium metal as an alternative conductor of automotive cables. This thesis work is to lay theoretical foundations for further research and development regarding the introduction of new automotive cables i.e. aluminium cables. Current application of automotive aluminium cables in automotive industry as well as failure analysis and eval...

Application of radioactivation analysis for determination of impurities in aluminium, raw materials and in samples from aluminium production process

International Nuclear Information System (INIS)

Vucina, L.J.

1977-01-01

Trace elements in aluminium, raw materials and in the samples from different stages of aluminium production were determined by nondestructive neutron radioactivation analysis. The samples were taken from the Bayer's process of alumina production (bauxite, red sludge and alumina), from the components of the reduction cell (anode, criolyte and AlF 3 ) and of the final product - aluminium (purity 99.5-99.7%). Under given set of conditions ten trace elements (V,La,Ga,Mn,Co,Cr,Sc,Sb,Zn and Fe) were determined in aluminium and followed through the production process. It was found that the main impurities in aluminium are iron (0.15%) and zinc (0.O6%). It has been concluded that the purity of produced aluminium depends mainly on the purity of used alumina. The second important source of contamination of aluminium is anode. The results obtained by radioactivation analysis for V, Mn, Cr and Fe fall within the ranges of concentrations of these elements determined by use of other methods (volumetry, spectrophotometry, atomic absorption). Higher values for zinc were obtained by radioactivation analysis, probably due to unsatisfactory irradiation and measuring conditions for this element. The possibilities of application of radioactivation analysis to these kinds of samples are also disscused

Microbial reduction of iron ore

Science.gov (United States)

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

Aluminium in allergen-specific subcutaneous immunotherapy--a German perspective.

Science.gov (United States)

Kramer, Matthias F; Heath, Matthew D

2014-07-16

We are living in an "aluminium age" with increasing bioavailability of the metal for approximately 125 years, contributing significantly to the aluminium body burden of humans. Over the course of life, aluminium accumulates and is stored predominantly in the lungs, bones, liver, kidneys and brain. The toxicity of aluminium in humans is briefly summarised, highlighting links and possible causal relationships between a high aluminium body burden and a number of neurological disorders and disease states. Aluminium salts have been used as depot-adjuvants successfully in essential prophylactic vaccinations for almost 100 years, with a convincing positive benefit-risk assessment which remains unchanged. However, allergen-specific immunotherapy commonly consists of administering a long-course programme of subcutaneous injections using preparations of relevant allergens. Regulatory authorities currently set aluminium limits for vaccines per dose, rather than per treatment course. Unlike prophylactic vaccinations, numerous injections with higher proportions of aluminium-adjuvant per injection are applied in subcutaneous immunotherapy (SCIT) and will significantly contribute to a higher cumulative life dose of aluminium. While the human body may cope robustly with a daily aluminium overload from the environment, regulatory cumulative threshold values in immunotherapy need further addressing. Based on the current literature, predisposing an individual to an unusually high level of aluminium, such as through subcutaneous immunotherapy, has the potential to form focal accumulations in the body with the propensity to exert forms of toxicity. Particularly in relation to longer-term health effects, the safety of aluminium adjuvants in immunotherapy remains unchallenged by health authorities - evoking the need for more consideration, guidance, and transparency on what is known and not known about its safety in long-course therapy and what measures can be taken to prevent or

Microbial leaching of low grade copper ores

International Nuclear Information System (INIS)

Rauf, A.; Ashfaq, M.

1991-01-01

Biotechnology is regarded as one of the most promising and revolutionary solution to various problems which are generally faced in the extraction of metals from their ores such as high energy, capital costs and environmental pollution. The paper deals with the study of low grade copper ores for their beneficiation and extraction of copper. The ores used were chalcopyrite and oxidized copper ores. Microorganisms play a vital role in the solubilization of valuable contents from ores such as copper and other metals. Studies have been conducted on the indigenous copper ores by using thiobacillus ferro oxidans and thiobacillus thio oxidans. For comparison purpose some experiments have also been conducted by chemical leaching. The results of bacterial leaching are encouraging. (author)

Spark counting technique with an aluminium oxide film

International Nuclear Information System (INIS)

Kawai, H.; Koga, T.; Morishima, H.; Niwa, T.; Nishiwaki, Y.

1980-01-01

Automatic spark counting of etch-pits on a polycarbonate film produced by nuclear fission fragments is now used for neutron monitoring in several countries. A method was developed using an aluminium oxide film instead of a polycarbonate as the neutron detector. Aluminium oxide films were prepared as follows: A cleaned aluminium plate as an anode and a nickel plate as a cathode were immersed in dilute sulfuric acid solution and electric current flowed between the electrodes at 12degC for 10-30 minutes. Electric current density was about 10 mA/cm 2 . The aluminium plate was then kept in boiling water for 10-30 minutes for sealing. The thickness of the aluminium oxide layer formed was about 1μm. The aluminium plate attached to a plate of suitable fissionable material, such as uranium or thorium, was irradiated with neutrons and set in a usual spark counter for fission track counting. One electrode was the aluminium plate and the other was an aluminized polyester sheet. Sparked pulses were counted with a usual scaler. The advantage of using spark counting with an aluminium oxide film for neutron monitoring is rapid measurement of neutron exposure, since chemical etching which is indispensable for spark counting with a polycarbonate detector film, is not needed. (H.K.)

Chlorine/chloride based processes for uranium ores

International Nuclear Information System (INIS)

1980-11-01

The CE Lummus Minerals Division was commissioned by The Department of Supply and Services to develop order-of-magnitude capital and operating cost estimates for chlorine/chloride-based processes for uranium ores. The processes are designed to remove substantially all radioactive consituents from the ores to render the waste products harmless. Two processes were selected, one for a typical low grade ore (2 lb. U 3 O 8 /ton ore) and one for a high grade ore (50 lbs U 3 O 8 /ton). For the low grade ore a hydrochloric acid leaching process was chosen. For high grade ore, a more complex process, including gaseous chlorination, was selected. Capital cost estimates were compiled from information obtained from vendors for the specified equipment. Building cost estimates and the piping, electrical and instrumentation costs were developed from the plant layout. Utility diagrams and mass balances were used for estimating utilities and consumables. Detailed descriptions of the bases for capital and operating cost estimates are given

Steam generated conversion coating on aluminium alloys

DEFF Research Database (Denmark)

Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

Aluminium and its alloys are widely used in aerospace industry owing to their high strength to weight ratio. The surface of aluminium under normal conditions has a thin oxide film (2.5-10 nm) responsible for its inherent corrosion resistance. This oxide film can further be converted or transformed...... into functional conversion coatings in order to enhance corrosion resistance and adhesion to paint systems. Chromium based conversion coatings have been extensively used on aluminium alloys to improve adhesion of subsequent paint layers and corrosion resistance. However, the use of hexavalent chromium is strictly...... regulated due to its toxic nature and suspected carcinogenicity. So, it is highly imperative to develop other alternatives for chrome conversion coatings. Treatment of aluminium with natural water at elevated temperatures results in the formation of different forms of aluminium oxide (γ-AlO(OH) , Al(OH)3...

A procedure for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores

International Nuclear Information System (INIS)

Zubcek, L.; Baloun, S.; Martinek, K.; Vebr, Z.; Krepelka, J.; Lasica, S.

1989-01-01

It is suggested that dust from the production of ferroalloys of manganese, particularly ferrosilicomanganese and ferromanganese, can be conveniently used for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores. This dust contains 30 to 40% oxides of manganese, about one-half of this is MnO 2 . Iron in the dust is present in the trivalent form, and the dust is pefectly dry. The conventional grinding of oxidants for the ore processing is eliminated, the dust being available in particle size below 0.2 mm. The dust is added in amounts of 5 to 100 kg per ton of the ore, and the suspension is typically heated at 115 degC for 3.5 hr. (P.A.)

Advances in development and application of aluminium batteries

DEFF Research Database (Denmark)

Qingfeng, Li; Zhuxian, Qiu

2001-01-01

Aluminium has long attracted attention as a potential battery anode because of its high theoretical voltage and specific energy. The protective oxide layer at aluminium surface is however detrimental to its performance to achieve its reversible potential, and also causing the delayed activation o...... aluminium batteres, especially aluminium-air batteries, and a wide range of their applications from emergency power supplies, reserve batteries field portable batteries, to batteries for electric vehicles and underwater propulsion....

Alveolar proteinosis associated with aluminium dust inhalation.

Science.gov (United States)

Chew, R; Nigam, S; Sivakumaran, P

2016-08-01

Secondary alveolar proteinosis is a rare lung disease which may be triggered by a variety of inhaled particles. The diagnosis is made by detection of anti-granulocyte-macrophage colony-stimulating factor antibodies in bronchoalveolar lavage fluid, which appears milky white and contains lamellar bodies. Aluminium has been suggested as a possible cause, but there is little evidence in the literature to support this assertion. We report the case of a 46-year-old former boilermaker and boat builder who developed secondary alveolar proteinosis following sustained heavy aluminium exposure. The presence of aluminium was confirmed both by histological examination and metallurgical analysis of a mediastinal lymph node. Despite cessation of exposure to aluminium and treatment with whole-lung lavage which normally results in improvements in both symptoms and lung function, the outcome was poor and novel therapies are now being used for this patient. It may be that the natural history in aluminium-related alveolar proteinosis is different, with the metal playing a mediating role in the disease process. Our case further supports the link between aluminium and secondary alveolar proteinosis and highlights the need for measures to prevent excessive aluminium inhalation in relevant industries. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Complexing and hydrothermal ore deposition

CERN Document Server

Helgeson, Harold C

1964-01-01

Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

International Nuclear Information System (INIS)

Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

2012-01-01

It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

Ion beam analysis of aluminium in thin layers

International Nuclear Information System (INIS)

Healy, M.J.F.; Pidduck, A.J.; Dollinger, G.; Gorgens, L.; Bergmaier, A.

2002-01-01

This work quantifies aluminium in thin surface and near surface layers. In one example, the layer overlies a thin gallium nitride layer on an aluminium oxide substrate and in a second example the aluminium exists just below the surface of an indium arsenide substrate. The technique of non-Rutherford elastic backscattering of protons was used for the samples where aluminum in the layer of interest needed to be resolved from aluminium in the sapphire substrate and the results were corroborated at the Technische Universitaet Muenchen using heavy ion elastic recoil detection analysis. In the second example, where it was unnecessary to isolate the signal of aluminium in the layer of interest (as the substrate contained no aluminium), then the 27 Al(d,p 01 ) 28 Al nuclear reaction was used. The elastic proton scattering cross section of aluminum was found to vary very rapidly over the energy range of interest

The aluminium content of infant formulas remains too high.

Science.gov (United States)

Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

2013-10-08

Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

Preparation of aluminium lakes by electrocoagulation

OpenAIRE

Prapai Pradabkham

2008-01-01

Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

Serum aluminium levels of workers in the bauxite mines.

Science.gov (United States)

de Kom, J F; Dissels, H M; van der Voet, G B; de Wolff, F A

1997-01-01

Aluminium is produced from the mineral bauxite. Occupational exposure is reported during the industrial processing of aluminium and is associated with pulmonary and neurotoxicity. However, data on exposure and toxicity of workers in the open bauxite mining industry do not exist. Therefore, a study was performed to explore aluminium exposure in employees involved in this bauxite mining process in a Surinam mine. A group of workers occupationally exposed to aluminium in an open bauxite mine were compared with a group of nonexposed wood processors. Serum aluminium was analyzed using atomic absorption spectrometry Data from the clinical chemistry of the blood and a questionnaire were used to explore determinants for aluminium exposure. No significant difference between serum aluminium in the exposed (4.4 +/- 2.0 micrograms/L, n = 27) and control group (5.1 +/- 1.5 micrograms/L, n = 27) was detected. For the serum concentration of the clinical chemical variables (calcium, citrate, and creatinine), a statistically significant difference was computed (p < or = 0.02) between the exposed and control group. All levels were slightly higher in the exposed group; no statistically significant correlations with serum aluminium were found. In this study, serum aluminium values were in the normal range, no significant difference between the groups could be detected despite long-term occupational exposure.

Argon-arc welding of heat resisting aluminium alloys

International Nuclear Information System (INIS)

Ryazantsev, V.I.; Fedoseev, V.A.

1997-01-01

Welding of aluminium heat resisting alloys of the Al-Cu-Mg system is studied. The hot-shortness of heat-resistant alloys M40, 1150 and 1151 are at the level of aluminium alloys 1201 and by 2-3 times lower as compared to the aluminium alloy AMg6. The M40, 1150 and 1151 alloys have unquestionable advantages against other know aluminium alloys only at temperatures of welded structures operation, beginning with 150-2000 deg C and especially at 250 deg C

Net shape powder processing of aluminium

International Nuclear Information System (INIS)

Schaffer, G.B.

2000-01-01

The increasing interest in light weight materials coupled to the need for cost-effective processing have combined to create a significant opportunity for aluminium powder metallurgy. Net shape processing of aluminium using the classical press-and-sinter powder metallurgy technique is a unique and important metal-forming method which is cost effective in producing complex parts at, or very close to, final dimensions. This paper provides an overview of the net shape powder processing of aluminium. Current research is critically reviewed and the future potential is briefly considered

Method of continuous pressure leaching of ores

International Nuclear Information System (INIS)

Fiala, P.; Baloun, S.; Polansky, M.

1987-01-01

Ore leaching, especially suspensions of ground ore or fine ore fractions from physical treatment was divided into two operations. The former, i.e., ore mixing with technical grade concentrated sulfuric acid proceeded in a separate mixer. The mixture was then transported into an autoclave where the actual leaching proceeded for 2 to 4 hours. The extracted mixture was discharged through the autoclave bottom. The leaching autoclave used can be without any inner structures. The separation of mixing from the actual leaching allows processing ores with high levels of clay components, increasing operating reliability of the facility, reducing consumption of special structural materials and energy, and increasing process efficiency. (E.S.)

Preparation of aluminium lakes by electrocoagulation

Directory of Open Access Journals (Sweden)

Prapai Pradabkham

2008-07-01

Full Text Available Aluminium lakes have been prepared by electrocoagulation employing aluminium as electrodes. The electrocoagulation is conducted in an aqueous alcoholic solution and is completed within one hour. The dye content in the lake ranges approximately between 4-32%.

Investigation of aluminium state in some popular food, which are cooked in aluminium vessels, using spectroscopic analysis methods

International Nuclear Information System (INIS)

Al-Shahneh, M.; Saheune, Kh.

2009-01-01

Aluminium and lead elements were determined in drinking water and salt solution from chick-pea and faba-bean cooked in aluminium vessels and others from teflon for comparison using atomic absorption spectroscopy by graphite furnace. The relationship between heating time and aluminium quantities transferred to these food solutions was investigated. The lead element was determined taking into consideration the fact that this element may enter in these vessels somehow during the manufacturing process. Results show that the highest value of aluminium quantities was recorded in salt solution ( 17.022 μg/ml) without heating , followed by chick-pea solution (9.95 μg/ml), then faba-bean solution (2.81 μg/ml) when the heated period was 120 minutes. (author)

Effect of tempering on corrosion resistance of cast aluminium bronzes

International Nuclear Information System (INIS)

Aaltonen, P.; Klemetti, K.; Haenninen, H.

1985-01-01

The subject of this study is corrosion resistance of aluminium bronzes, which are copper base alloys containing aluminium up to 12% with additions of nickel, iron and manganese. The main conclutions that can be drawn are: (1) The dealloying corrosion resistance of nickel-aluminium bronze is much better than that of aluminium bronze with iron and manganese additions, but it is not immune; (2) The dealloying corrosion resistance of aluminium bronzes can be improved by appropiate heat treatments. The best properties were obtained by temperering between 600 and 800 deg C, depending on the initial microstructure; (3) In crevice conditions, where local acidification can occur, dealloying of aluminium bronzes is a consequence of the preferential attack of aluminium-rich phases. By appropriate tempering, a uniform distribution of aluminium-rich phases is obtained and the continous path for selective corrosion is not formed

What is the risk of aluminium as a neurotoxin?

Science.gov (United States)

Exley, Christopher

2014-06-01

Aluminium is neurotoxic. Its free ion, Al(3+) (aq), is highly biologically reactive and uniquely equipped to do damage to essential cellular (neuronal) biochemistry. This unequivocal fact must be the starting point in examining the risk posed by aluminium as a neurotoxin in humans. Aluminium is present in the human brain and it accumulates with age. The most recent research demonstrates that a significant proportion of individuals older than 70 years of age have a potentially pathological accumulation of aluminium somewhere in their brain. What are the symptoms of chronic aluminium intoxication in humans? What if neurodegenerative diseases such as Alzheimer's disease are the manifestation of the risk of aluminium as a neurotoxin? How might such an (outrageous) hypothesis be tested?

Detection of aluminium in different culinary media using black ...

African Journals Online (AJOL)

Jacques Blessing

The interactions between food and aluminium local kitchen utensils can be a potential source of aluminium released which can ... need to be adopted to preserve consumers' health. ..... Corrosion behaviour of different ... Aluminium beverage.

The treatment of uranium ores

International Nuclear Information System (INIS)

Michel, P.

1979-01-01

After having described the main steps in the treatment of uranium ores, the author describes the treament activities for these ores, as they are organized in France and in the African countries having made cooperation agreements with France in this field [fr

There is (still too much aluminium in infant formulas

Directory of Open Access Journals (Sweden)

Burrell Shelle-Ann M

2010-08-01

Full Text Available Abstract Background Infant formulas are sophisticated milk-based feeds for infants which are used as a substitute for breast milk. Historically they are known to be contaminated by aluminium and in the past this has raised health concerns for exposed infants. We have measured the aluminium content of a number of widely used infant formulas to determine if their contamination by aluminium and consequent issues of child health persists. Methods Samples of ready-made milks and powders used to make milks were prepared by microwave digestion of acid/peroxide mixtures and their aluminium content determined by THGA. Results The concentration of aluminium in ready-made milks varied from ca 176 to 700 μg/L. The latter concentration was for a milk for preterm infants. The aluminium content of powders used to make milks varied from ca 2.4 to 4.3 μg/g. The latter content was for a soya-based formula and equated to a ready-to-drink milk concentration of 629 μg/L. Using the manufacturer's own guidelines of formula consumption the average daily ingestion of aluminium from infant formulas for a child of 6 months varied from ca 200 to 600 μg of aluminium. Generally ingestion was higher from powdered as compared to ready-made formulas. Conclusions The aluminium content of a range of well known brands of infant formulas remains high and particularly so for a product designed for preterm infants and a soya-based product designed for infants with cow's milk intolerances and allergies. Recent research demonstrating the vulnerability of infants to early exposure to aluminium serves to highlight an urgent need to reduce the aluminium content of infant formulas to as low a level as is practically possible.

Molybdenum solubility in aluminium nitrate solutions

Energy Technology Data Exchange (ETDEWEB)

Heres, X.; Sans, D.; Bertrand, M.; Eysseric, C. [CEA, Centre de Marcoule, Nuclear Energy Division, DRCP, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Brackx, E.; Domenger, R.; Excoffier, E. [CEA, Centre de Marcoule, Nuclear Energy Division, DTEC, BP 17171, 30207 Bagnols-sur-Ceze Cedex (France); Valery, J.F. [AREVA-NC, DOR/RDP, Paris - La Defense (France)

2016-07-01

For over 60 years, research reactors (RR or RTR for research testing reactors) have been used as neutron sources for research, radioisotope production ({sup 99}Mo/{sup 99m}Tc), nuclear medicine, materials characterization, etc... Currently, over 240 of these reactors are in operation in 56 countries. They are simpler than power reactors and operate at lower temperature (cooled to below 100 C. degrees). The fuel assemblies are typically plates or cylinders of uranium alloy and aluminium (U-Al) coated with pure aluminium. These fuels can be processed in AREVA La Hague plant after batch dissolution in concentrated nitric acid and mixing with UOX fuel streams. The aim of this study is to accurately measure the solubility of molybdenum in nitric acid solution containing high concentrations of aluminium. The higher the molybdenum solubility is, the more flexible reprocessing operations are, especially when the spent fuels contain high amounts of molybdenum. To be most representative of the dissolution process, uranium-molybdenum alloy and molybdenum metal powder were dissolved in solutions of aluminium nitrate at the nominal dissolution temperature. The experiments showed complete dissolution of metallic elements after 30 minutes long stirring, even if molybdenum metal was added in excess. After an induction period, a slow precipitation of molybdic acid occurs for about 15 hours. The data obtained show the molybdenum solubility decreases with increasing aluminium concentration. The solubility law follows an exponential relation around 40 g/L of aluminium with a high determination coefficient. Molybdenum solubility is not impacted by the presence of gadolinium, or by an increasing concentration of uranium. (authors)

Guide lines for control and supervision of dump leaching. Application to the inframarginal uranium ore of the Cellier mine

International Nuclear Information System (INIS)

Pineau, J.L.; Yvon, J.; Blazy, P.

1984-01-01

The Cellier mine processes inframarginal uranium ores by a slow dump leaching. Fragmentary information concerning the evolution of the chemical properties of the solutions (inflow-outflow) as a function of the time has been the object of an analysis of data. The latter, which was both descriptive and predictive, made it possible on the one hand to identify facts which have intervened at the time of leaching and on the other hand to pinpoint the influence of the time factor and of the associations of chemical elements (aluminium, phosphorus, etc.) on the passing into solution of the uranium. As this treatment gives only a global view of the problem, it was completed by a mineralogical analysis. The fine mineralogical analysis of the fractions, made soluble by sulphuric attack in a heap, shows that sulphated concretions isolate the uranium from the leaching liquor. A screen of sulphate is composed of a macroscopic web of gypsum (calcium sulphate) in which a microscopic web of hydrated magnesium sulphate is inserted. In the gypsum web are trapped phosphorus minerals and in the magnesium sulphate web manganese and aluminium minerals. As regards the uranium, it is either distributed in the form of fine inclusions of uranyl hydroxide, or associated to chlorinated forms, derived from the treatment aids [fr

Niobium-base grain refiner for aluminium

International Nuclear Information System (INIS)

Silva Pontes, P. da; Robert, M.H.; Cupini, N.L.

1980-01-01

A new chemical grain refiner for aluminium has been developed, using inoculation of a niobium-base compound. When a bath of molten aluminium is inoculated whith this refiner, an intermetallic aluminium-niobium compound is formed which acts as a powerful nucleant, producing extremely fine structure comparable to those obtained by means of the traditional grain refiner based on titanium and boron. It was found that the refinement of the structure depends upon the weight percentage of the new refiner inoculated as well as the time of holding the bath after inoculation and before pouring, but mainly on the inoculating temperature. (Author) [pt

IEC 61267: Feasibility of type 1100 aluminium and a copper/aluminium combination for RQA beam qualities.

Science.gov (United States)

Leong, David L; Rainford, Louise; Zhao, Wei; Brennan, Patrick C

2016-01-01

In the course of performance acceptance testing, benchmarking or quality control of X-ray imaging systems, it is sometimes necessary to harden the X-ray beam spectrum. IEC 61267 specifies materials and methods to accomplish beam hardening and, unfortunately, requires the use of 99.9% pure aluminium (Alloy 1190) for the RQA beam quality, which is expensive and difficult to obtain. Less expensive and more readily available filters, such as Alloy 1100 (99.0% pure) aluminium and copper/aluminium combinations, have been used clinically to produce RQA series without rigorous scientific investigation to support their use. In this paper, simulation and experimental methods are developed to determine the differences in beam quality using Alloy 1190 and Alloy 1100. Additional simulation investigated copper/aluminium combinations to produce RQA5 and outputs from this simulation are verified with laboratory tests using different filter samples. The results of the study demonstrate that although Alloy 1100 produces a harder beam spectrum compared to Alloy 1190, it is a reasonable substitute. A combination filter of 0.5 mm copper and 2 mm aluminium produced a spectrum closer to that of Alloy 1190 than Alloy 1100 with the added benefits of lower exposures and lower batch variability. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Remediation of phosphate-contaminated water by electrocoagulation with aluminium, aluminium alloy and mild steel anodes.

Science.gov (United States)

Vasudevan, Subramanyan; Lakshmi, Jothinathan; Jayaraj, Jeganathan; Sozhan, Ganapathy

2009-05-30

The present study provides an electrocoagulation process for the remediation of phosphate-contaminated water using aluminium, aluminium alloy and mild steel as the anodes and stainless steel as the cathode. The various parameters like effect of anode materials, effect of pH, concentration of phosphate, current density, temperature and co-existing ions, and so forth, and the adsorption capacity was evaluated using both Freundlich and Langmuir isotherm models. The adsorption of phosphate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The results showed that the maximum removal efficiency of 99% was achieved with aluminium alloy anode at a current density of 0.2 A dm(-2), at a pH of 7.0. The adsorption process follows second-order kinetics.

Human biomonitoring of aluminium after a single, controlled manual metal arc inert gas welding process of an aluminium-containing worksheet in nonwelders.

Science.gov (United States)

Bertram, Jens; Brand, Peter; Hartmann, Laura; Schettgen, Thomas; Kossack, Veronika; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

2015-10-01

Several existing field studies evaluate aluminium welding works but no thoroughly controlled exposure scenario for welding fume has been described yet. This study provides information about the uptake and elimination of aluminium from welding fumes under controlled conditions. In the Aachen Workplace Simulation Laboratory, we are able to generate welding fumes of a defined particle mass concentration. We exposed 12, until then occupationally unexposed participants with aluminium-containing welding fumes of a metal inert gas (MIG) welding process of a total dust mass concentration of 2.5 mg/m(3) for 6 h. Room air filter samples were collected, and the aluminium concentration in air derived. Urine and plasma samples were collected directly before and after the 6-h lasting exposure, as well as after 1 and 7 days. Human biomonitoring methods were used to determine the aluminium content of the samples with high-resolution continuum source atomic absorption spectrometry. Urinary aluminium concentrations showed significant changes after exposure compared to preexposure levels (mean t(1) (0 h) 13.5 µg/L; mean t(2) (6 h) 23.5 µg/L). Plasma results showed the same pattern but pre-post comparison did not reach significance. We were able to detect a significant increase of the internal aluminium burden of a single MIG aluminium welding process in urine, while plasma failed significance. Biphasic elimination kinetic can be observed. The German BAT of 60 µg/g creatinine was not exceeded, and urinary aluminium returned nearly to baseline concentrations after 7 days.

Multiply-negatively charged aluminium clusters and fullerenes

Energy Technology Data Exchange (ETDEWEB)

Walsh, Noelle

2008-07-15

Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)

Sedimentary exhalative nickel-molybdenum ores in south China

Science.gov (United States)

Lott, D.A.; Coveney, R.M.; Murowchick, J.B.; Grauch, R.I.

1999-01-01

Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

Irradiation of aluminium alloy materials with electron beam

International Nuclear Information System (INIS)

Konno, Osamu; Masumoto, Kazuyoshi

1982-01-01

It is a theme with a room for discussion to employ the stainless steel composed of longer half-life materials for the vacuum system of accelerators, from the viewpoint of radiation exposure. Therefore, it is desirable to use aluminium of shorter half-life in place of stainless steel. As a result of investigation on the above theme in the 1.2 GeV electron linac project in Tohoku University, it has been concluded that aluminium alloy vacuum chambers can reduce exposure dose by about one or two figures as compared with stainless steel ones. Of course, aluminium alloy contains trace amounts of Mg, Si, Ti, Cr, Mn, Fe, Zn, Cu and others. Therefore, four kinds of aluminium alloy considered to be usable have been examined for induced radioactivity by electron beam irradiation. Stainless steel SUS 304 has been also irradiated for comparison. Radiation energy has been 30 MeV and 200 MeV. When stainless steel and aluminium alloy were compared, aluminium alloy was very effective for reducing surface dose in low energy irradiation. In 200 MeV irradiation, the dose ratio of aluminium alloy to stainless steel became 1/30 to 1/100 after one week, though the dose difference between these two materials became smaller in 100 days or more after irradiation. If practical inspection and repair are implemented during the period from a few days to one week after shutdown, the aluminium alloy is preferable for exposure dose reduction even in high energy irradiation. (Wakatsuki, Y.)

Introduction. Aluminium production on electrolytic cells with calcined anodes

International Nuclear Information System (INIS)

Galushkin, N.V.

1995-01-01

This chapter presents the monograph content, which includes the description of physicochemical processes in aluminium electrolytic cells, and mechanism of electrolytic aluminium obtaining. The short description of aluminium electrolytic cells construction is presented in this book as well.

Aluminium allergy and granulomas induced by vaccinations for children

DEFF Research Database (Denmark)

Andersen, Rosa Marie O; Zachariae, Claus; Johansen, Jeanne Duus

2014-01-01

Vaccination with aluminium-adsorbed vaccines can induce aluminium allergy with persistent itching subcutaneous nodules at the injection site - vaccination granulomas. In this article we give an overview of childhood aluminium-adsorbed vaccines available in Denmark. Through literature studies we...

Synthesis and properties of bimetallic aluminium alkoxides

International Nuclear Information System (INIS)

Vyshinskaya, K.I.; Vasil'ev, G.A.; Vishnyakova, T.A.

1997-01-01

A single stage method of aluminium bimetallic alkoxide synthesis, which consists in activated aluminium reaction with metal salts in the relevant alcohols, has been developed. Properties of the compounds prepared are described

Beryllium electrodeposition on aluminium cathode from chloride melts

International Nuclear Information System (INIS)

Nichkov, I.F.; Novikov, E.A.; Serebryakov, G.A.; Kanashin, Yu.P.; Sardyko, G.N.

1980-01-01

Cathodic processes during beryllium deposition on liquid and solid aluminium cathodes are investigated. Mixture of sodium, potassium and beryllium chloride melts served as an lectrolyte. Beryllium ion discharge at the expense of alloy formation takes place at more positive potentials than on an indifferent cathode at low current densities ( in the case of liquid aluminium cathode). Metallographic analysis and measurements of microhardness have shown, that the cathodic product includes two phases: beryllium solid solution in aluminium and metallic beryllium. It is concluded, that aluminium-beryllium alloys with high cathodic yield by current can be obtained by the electrolytic method

Investigation process of alcoholysis of hydride aluminium-adobe

International Nuclear Information System (INIS)

Numanov, M.I.; Normatov, I.Sh.; Mirsaidov, U.M.

2001-01-01

Considering of that process of acid treatment of aluminium-adobe hydride realizes in the ethyl alcohol media it was necessary study the process of alcoholysis of AlH 3 and aluminium additives. In the end of article authors became to conclusion that deficiency of spontaneous alcoholysis of AlH 3 in adobe caused by protective action of fiber; solvate ability of LiCl and alkoxy aluminium hydride of lithium-LiCl·CO 2 H 5 OH, Li Al(OC 2 H 5 ) 4 ·nC 2 H 5 OH decreasing the expectancy of responding of alcohol with aluminium hydride

KS R41B. A high performance steel-aluminium composite material; KS R41B. Ein Stahl-Aluminium-Verbundwerkstoff fuer hohe Belastungen

Energy Technology Data Exchange (ETDEWEB)

Deicke, K. [KS Gleitlager GmbH (Germany). Bereich Metall; Matucha, H.; Schubert, W. [KS Gleitlager GmbH, St. Leon-Rot (Germany); Steffens, T. [KS Gleitlager GmbH, Neckarsulm (Germany)

2002-08-01

Aluminium-tin alloys have been well-known for a long time and have proved to be suitable bearing materials for crankshaft bearings for many years. The known alloy AlZn4,5SiCuPb is one of the aluminium materials capable of sustaining the highest mechanical loads. In order to achieve optimum sliding properties, it would be necessary to increase the share of the soft lead phase in the alloy. This article by KS Gleitlager GmbH shows a reasonably priced manufacturing technology for high-performance aluminium-zinc-silicon-copper alloys. (orig.) [German] Die Aluminium-Zinn-Lagerlegierungen sind seit langem bekannt und haben sich seit Jahren als Lagerwerkstoff fuer Kurbelwellenlager bewaehrt. Die Legierung AlZn4,5SiCuPb gehoert zu den mechanisch am hoechsten belastbaren Aluminium-Werkstoffen. Um optimale Gleiteigenschaften zu erzielen, muesste in der Legierung der Anteil des weichen Bleis noch weiter erhoeht werden. Dieser Beitrag der KS Gleitlager GmbH zeigt eine kostenguenstige Herstelltechnologie fuer hochbelastbare Aluminium-Zink-Silizium-Kupfer-Legierungen. (orig.)

Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

NARCIS (Netherlands)

De Kanter, J.L.C.G.

2006-01-01

Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

Corrosion of aluminium in copper-aluminium couples under a marine environment: Influence of polyaniline deposited onto copper

International Nuclear Information System (INIS)

Vera, Rosa; Verdugo, Patricia; Orellana, Marco; Munoz, Eduardo

2010-01-01

Research highlights: → The presence of Polyaniline in the Al-Cu system produces a decrease in the oxygen reduction reaction. → In the marine enviroment, aluminium in Al-Cu couples, suffers pitting and exfoliation. → The aluminium deterioration increases with chloride and enviromental sulphur dioxide presence, mainly when it is united to bare copper. - Abstract: In this study, we examined how aluminium corrosion in Al-Cu/PANI galvanic couples in a marine environment is influenced by deposition of polyaniline (PANI) on copper. Polarization curves and immersion assays in 0.1 M NaCl were performed. The morphologies of etched Al and corrosion products were observed by SEM, and the Al ions in solution were quantified by atomic absorption spectroscopy. A reduction in aluminium damage due to galvanic corrosion was observed as a result of decreased effective area for the oxygen reduction reaction on Cu/PANI electrode. Furthermore, an electrochemical reduction of PANI from leucoemeraldine to emeraldine base is proposed.

Aluminium hydroxide-the carrier for catalysts coating

International Nuclear Information System (INIS)

Normatov, I.Sh.; Mirsaidov, U.M.

2003-01-01

At present time several methods of receiving aluminium hydroxide are exist. But all they differ by much staging of process connected with preliminary receiving of intermediate compounds, with application of expensive metallic aluminium

Effects of aluminium surface morphology and chemical modification on wettability

DEFF Research Database (Denmark)

Rahimi, Maral; Fojan, Peter; Gurevich, Leonid

2014-01-01

-life aluminium surfaces of different morphology: unpolished aluminium, polished aluminium, and aluminium foil, were subjected to surface modification procedures which involved the formation of a layer of hydrophilic hyperbranched polyethyleneglycol via in situ polymerization, molecular vapour deposition...... of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types...

A procedure for acid leaching of ores of the sandstone type, particularly of uranium ores

International Nuclear Information System (INIS)

Fiala, P.; Baloun, S.; Hinterholzinger, O.

1990-01-01

Ore mixed with the enriched fraction of the leached ore is leached with sulfuric acid at 5 to 220 degC. Bulky particles are sorted out from the mixture and reduced in size, and particles with a higher proportion of the useful component are separated from them. The latter particles constitute the enriched fraction of the leached ore, which is partially or completely returned to the mixture with the entering ore. The sorting should preferably be performed in an aqueous system. The assets of this procedure include a better homogenization of the mixture with the acid, a better stability of the reaction mixture which brings about reduced adhesion and solidification, and the possibility of extending the reaction time and increasing the temperature. The reduction in size makes for a better access of the leaching agent to the useful minerals, and the returning of the leachate to the reaction system spares sulfuric acid. (M.D.)

Aluminium removal from water after defluoridation with the electrocoagulation process.

Science.gov (United States)

Sinha, Richa; Mathur, Sanjay; Brighu, Urmila

2015-01-01

Fluoride is the most electronegative element and has a strong affinity for aluminium. Owing to this fact, most of the techniques used for fluoride removal utilized aluminium compounds, which results in high concentrations of aluminium in treated water. In the present paper, a new approach is presented to meet the WHO guideline for residual aluminium concentration as 0.2 mg/L. In the present work, the electrocoagulation (EC) process was used for fluoride removal. It was found that aluminium content in water increases with an increase in the energy input. Therefore, experiments were optimized for a minimum energy input to achieve the target value (0.7 mg/L) of fluoride in resultant water. These optimized sets were used for further investigations of aluminium control. The experimental investigations revealed that use of bentonite clay as coagulant in clariflocculation brings down the aluminium concentration of water below the WHO guideline. Bentonite dose of 2 g/L was found to be the best for efficient removal of aluminium.

Irradiation effects in magnesium and aluminium alloys

International Nuclear Information System (INIS)

Sturcken, E.F.

1979-01-01

Effects of neutron irradiation on microstructure, mechanical properties and swelling of several magnesium and aluminium alloys were studied. The neutron fluences of 2-3 X 10 22 n/cm 2 , >0.2 MeV produced displacement doses of 20 to 45 displacements per atom (dpa). Ductility of the magnesium alloys was severely reduced by irradiation induced recrystallization and precipitation of various forms. Precipitation of transmuted silicon occurred in the aluminium alloys. However, the effect on ductility was much less than for the magnesium alloys. The magnesium and aluminium alloys had excellent resistance to swelling: The best magnesium alloy was Mg/3.0 wt% Al/0.19 wt% Ca; its density decreased by only 0.13%. The best aluminium alloy was 6063, with a density decrease of 0.22%. (Auth.)

Steam Initiated Surface Modification of Aluminium Alloys

DEFF Research Database (Denmark)

Din, Rameez Ud

The extensive demand of aluminium alloys in various industries such as in transportationis mainly due to the high strength to weight ratio, which could be translated into fuel economy and efficiency. Corrosion protection of aluminium alloys is an important aspect for all applications which includes...... the use of aluminium alloys in the painted form requiring a conversion coating to improve the adhesion. Chromate based conversion coating processes are extremely good for these purposes, however the carcinogenic and toxic nature of hexavalent chromium led to the search for more benign and eco......, crystalline nano-particles, role of steam-based treatment on adhesion of industrially applied powder coating, and investigations of a failed painted aluminium window profile due to defects in the extruded profile. Chapters 13 and 14 describe the overall discussion, conclusions and future work based...

Deformation features of aluminium in tensile tests

International Nuclear Information System (INIS)

Quadros, N.F. de.

1984-01-01

It is presented a method to analyse stress-strain curves. Plastic and elastic strains were studied. The strains were done by tensile tests in four types of materials: highly pure aluminium, pure aluminium, commercially pure aluminium and aluminium - uranium. The chemical compositions were obtained by spectroscopy analysis and neutron activation analysis. Tensile tests were carried out at three strain rates, at room temperature, 100,200, 300 and 400 0 C, with knives extensometer and strain-gages to studied the elastic strain region. A multiple spring model based on two springs model to analyse elastic strain caused by tests without extensometers, taking in account moduli of elasticity and, an interactive analysis system with graphic capability were developed. It was suggested a qualitative model to explain the quantized multielasticity of Bell. (M.C.K.) [pt

Dielectric aluminium phosphate thin films. Couches minces dielectriques de phosphate d'aluminium

Energy Technology Data Exchange (ETDEWEB)

Daviero, S. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Avinens, C. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Ibanez, A. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Giuntini, J.C. (Lab. Physicochimie des Materiaux Solides, 34 -Montpellier (France)); Philippot, E. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France))

1993-04-01

Aluminium phosphate thin films on silicium substrate have been carried out from tributylphosphate and aluminium acetylacetonate precursors in solution through the ''pyrosol'' process. It can be observed a large range of chemical analysis in terms of experimental conditions. These thin films have been characterized by X-ray diffraction and infrared spectrometry. Their electrical characteristics, defined from direct current and alternative current measurements, are quite different to those of the crystallized phosphate and can be explained by P-O and Al-O ''dangling bond'' existence. (orig.).

Rapidly solidified aluminium for optical applications

NARCIS (Netherlands)

Gubbels, G.P.H.; Venrooy, B.W.H. van; Bosch, A.J.; Senden, R.

2008-01-01

This paper present the results of a diamond turning study of a rapidly solidified aluminium 6061 alloy grade, known as RSA6061. It is shown that this small grain material can be diamond turned to smaller roughness values than standard AA6061 aluminium grades. Also, the results are nearly as good as

[Determination of aluminium in flour foods with photometric method].

Science.gov (United States)

Ma, Lan; Zhao, Xin; Zhou, Shuang; Yang, Dajin

2012-05-01

To establish a determination method for aluminium in flour foods with photometric method. After samples being treated with microwave digestion and wet digestion, aluminium in staple flour foods was determined by photometric method. There was a good linearity of the result in the range of 0.25 - 5.0 microg/ml aluminium, r = 0.9998; limit of detection (LOD) : 2.3 ng/ml; limit of quantitation (LOQ) : 7 ng/ml. This method of determining aluminium in flour foods is simple, rapid and reliable.

Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance

International Nuclear Information System (INIS)

Gaboreau, St.

2005-01-01

Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO 2 and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

Comparison of reactivity to a metallic disc and 2% aluminium salt in 366 children, and reproducibility over time for 241 young adults with childhood vaccine-related aluminium contact allergy.

Science.gov (United States)

Gente Lidholm, Anette; Inerot, Annica; Gillstedt, Martin; Bergfors, Elisabet; Trollfors, Birger

2018-07-01

An aluminium hydroxide-adsorbed pertussis toxoid vaccine was studied in 76 000 children in the 1990s in Gothenburg, Sweden. Long-lasting itchy subcutaneous nodules at the vaccination site were seen in 745 participants. Of 495 children with itchy nodules who were patch tested for aluminium allergy, 377 were positive. In 2007-2008, 241 of the positive children were retested. Only in one third were earlier positive results reproduced. To further describe patch test reactions to different aluminium compounds in children with vaccine-induced aluminium allergy. Positive patch test results for metallic aluminium (empty Finn Chamber) and aluminium chloride hexahydrate 2% petrolatum (pet.) were analysed in 366 children with vaccine-induced persistent itching nodules tested in 1998-2002. Of those, 241 were tested a second time (2007-2008), and the patch test results of the two aluminium preparations were analysed. Patch testing with aluminium chloride hexahydrate 2% pet. is a more sensitive way to diagnose aluminium contact allergy than patch testing with metallic aluminium. A general decrease in the strength of reactions to both aluminium preparations in 241 children tested twice was observed. Aluminium contact allergy can be diagnosed by patch testing without using metallic aluminium. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

Science.gov (United States)

Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.

2001-03-01

Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

Directory of Open Access Journals (Sweden)

Juan Enrique Villalva A.

2015-11-01

Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

Uranium reduction by carbon oxide during ore formation

International Nuclear Information System (INIS)

Matyash, I.V.; Gavrusevich, I.B.; Pasal'skaya, L.F.; Shcherba, D.I.

1981-01-01

Using the method of gas chromatography the gas content in Pre-Cambrian granitoils of various types and in natrometasomatites associted with them is studied. It is established that granites associated with ore-bearing albitites have sharply elevated amounts of CO as compared with granites, which do not include mineralization. Simultaneously in ore samples the absence or sharply low amounts of CO as compared with ore-free samples is observed, that is reverse dependence of CO and ore components. Carbon oxide is the reducing agent of uranium mineralization and alongside with other reducing agents can be a geochemical barrier in the process of ore formation [ru

Effect of smelt aluminium on mechanical properties of steels

International Nuclear Information System (INIS)

Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

1987-01-01

Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

Study of corrosion in aluminium using neutron radiography technique

International Nuclear Information System (INIS)

Islam, M.N.; Alam, M.K.; Saklayen, M.A.; Ahsan, M.H.; Islam, S.M.A.; Zaman, M.A.

2000-01-01

Neutron radiography technique has been adopted for detection of corrosion in aluminium by filling artificially made holes on aluminium slab with Al(OH) 3 . The contrast between the optical densities of corrosion products and aluminium slab was assessed from the densitometric measurements. Variation of optical density difference with sample thickness has also been studied. The results confirm that approximately 0.039 mm thick corrosion products having diameter 10 mm can easily be detected in 2 cm thick aluminium slab. The linear attenuation coefficient of Al(OH) 3 has been obtained as 0.9447. From the present investigation it is confirmed that film neutron radiography (NR) technique is helpful for investigation of Al(OH) 3 type corrosion product in aluminium. (author)

Introduction to ore geology

International Nuclear Information System (INIS)

Evans, A.M.

1987-01-01

This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint

The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

Directory of Open Access Journals (Sweden)

Peter J. Williams

2010-04-01

Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

China's emergence as the world's leading iron-ore-consuming country

Science.gov (United States)

Kirk, W.S.

2004-01-01

China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

Effects of aluminium surface morphology and chemical modification on wettability

Energy Technology Data Exchange (ETDEWEB)

Rahimi, M., E-mail: mar@sbi.aau.dk [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark); Fojan, P.; Gurevich, L. [Department of Physics and Nanotechnology, Aalborg University, Skjernvej 4, DK-9220 Aalborg East (Denmark); Afshari, A. [Department of Energy and Environment, Danish Building Research Institute, Aalborg University, A.C. Meyers Vænge 15, 2450 København SV (Denmark)

2014-03-01

Highlights: • Successful surface modification procedures on aluminium samples were performed involving formation of the layer of hydrophilic hyperbranched polyethyleneglycol (PEG) via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. • The groups of surfaces with hydrophobic behavior were found to follow the Wenzel model. • A transition from Cassie–Baxter's to Wenzel's regime was observed due to changing of the surface roughness upon mechanical polishing in aluminium samples. - Abstract: Aluminium alloys are some of the predominant metals in industrial applications such as production of heat exchangers, heat pumps. They have high heat conductivity coupled with a low specific weight. In cold working conditions, there is a risk of frost formation on the surface of aluminium in the presence of water vapour, which can lead to the deterioration of equipment performance. This work addresses the methods of surface modification of aluminium and their effect of the underlying surface morphology and wettability, which are the important parameters for frost formation. Three groups of real-life aluminium surfaces of different morphology: unpolished aluminium, polished aluminium, and aluminium foil, were subjected to surface modification procedures which involved the formation of a layer of hydrophilic hyperbranched polyethyleneglycol via in situ polymerization, molecular vapour deposition of a monolayer of fluorinated silane, and a combination of those. The effect of these surface modification techniques on roughness and wettability of the aluminium surfaces was elucidated by ellipsometry, contact angle measurements and atomic force microscopy. We demonstrated that by employing different types of surface modifications the contact angle of water droplets on aluminium samples can be varied from 12° to more than 120°. A crossover from Cassie–Baxter to Wenzel regime upon changing the surface

Spectrophotometric determination of aluminium in steel with xylenol orange

International Nuclear Information System (INIS)

Majeed, A.; Javed, N.; Khan, M.S.

1996-01-01

Spectrophotometric determination of Aluminium in steel based on colour reaction between Aluminium and xylenol orange has been carried out. Red coloured complex formed in weak acidic solution is measured for its absorbance at 550 nm. The various optimum experimental conditions for Aluminium xylenol orange (Al-Xo) complex have been studied. (author)

Wear behavior of carbon fiber/aluminium-composites during abrasive loading; Verschleissverhalten von Kohlenstoffaser/Aluminium-Verbunden unter abrasiver Beanspruchung

Energy Technology Data Exchange (ETDEWEB)

Wielage, B.; Dorner, A. [Technische Univ. Chemnitz (Germany). Lehrstuhl fuer Verbundwerkstoffe

1998-07-01

Abrasive wear resistance of aluminium is significantly improved by the reinforcement with a high volume percentage of carbon fibres. The wear of unreinforced aluminium after scratching by a diamond indenter can be described as pure microgrooving without any micro-chipping. After integration of 70 vol.-% carbon fibers the damage mechanism is considerably altered and a great amount of micro-chipping occurs. The abrasive wear is strongly influenced by the fiber orientation. The best wear resistance is observed when the fibers are orientated perpendicular to the wear surface. (orig.) [Deutsch] Die Verstaerkung von Aluminium mit einem hohen Volumengehalt endloser Kohlenstoffasern verbessert erkennbar dessen Resistenz gegenueber Abrasionsverschleiss. Der Verschleiss von unverstaerktem Aluminium infolge des Ritzens mit einem Diamantindenter erfolgt in Form von reinem Mikrofurchen ohne Spanbildung. Aufgrund der Integration von 70 Vol.-% Kohlenstoffasern wird eine erhebliche Zunahme des Schaedigungsmechanismus Mikrospanen festgestellt. Die Faserorientierung hat merklichen Einfluss auf die Sensibilitaet gegenueber Abrasion. Orientierung der anisotropen Kohlenstoffasern senkrecht zur Verschleissoberflaeche bedingt den geringsten Abrasionsverschleiss. (orig.)

Improved leaching process for metal ores

International Nuclear Information System (INIS)

Kar-Kwan Yung, K.; Barlow, C.B.; Glass, J.R.

1980-01-01

The general overall sequence of process steps in the technique of the invention in set forth. In sequence, the ore is crushed, and solubilizing reagents and moisture are added to the crushed ore in preselected controlled portions. The mixture of ore, reagent, and moisture is then cured followed in the preferred process by conditioning for filtration. The slurry that is produced from conditioning is then subjected to multiple stage washing on a belt filter. The filtrate is further processed for metal value recovery and the solids are transported to tailings disposal

Study of ionic movements during anodic oxidation of nitrogen-implanted aluminium

International Nuclear Information System (INIS)

Terwagne, G.; Lucas, S.; Bodart, F.; Sorensen, G.; Jensen, H.

1990-01-01

In recent years there has been a considerable interest in synthesizing aluminium nitrides by ion implantation in order to modify the tribological properties of aluminium. The growth of an oxide layer by anodic process on these synthesized aluminium nitrides gives an interesting oxide-on-semiconductor material with surprising dynamic and decorative properties. During the anodic oxidation, ionic movements are involved in the near-surface region of the aluminium material; these ionic movements have been studied by Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) on thin aluminium foils (7000 A) preimplanted with nitrogen and post-oxidized in an ammonium pentaborate solution. The growth of the oxide layer is reduced when the aluminium is preimplanted with nitrogen: the speed of oxidation depends on the implantation conditions (energy and fluence). Moreover, the aluminium nitride can be dissolved when all metallic aluminium staying between the surface and the AlN are consumed by the anodic process. (orig.)

Steam Assisted Accelerated Growth of Oxide Layer on Aluminium Alloys

DEFF Research Database (Denmark)

Din, Rameez Ud; Yuksel, Serkan; Jellesen, Morten Stendahl

2013-01-01

Corrosion resistance of aluminium alloys is related to the composition and morphology of the oxide film on the surface of aluminium. In this paper we investigated the use of steam on the surface modification of aluminium to produce boehmite films. The study reveals a detailed investigation...... of the effect of vapour pressure, structure of intermetallic particles and thickness of boehmite films on the corrosion behaviour of aluminium alloys....

Aqueous-chlorine leaching of typical Canadian uranium ores

International Nuclear Information System (INIS)

Haque, K.E.

1982-01-01

Laboratory-scale aqueous-chlorine leaches were conducted on quartz-pebble conglomerates, pegmatite and vein-type ores. Optimum leach temperatures, pulp density and retention times were determined. Uranium extraction of 98 per cent was obtained from the Elliot Lake, Madawaska Mines of Bancroft and Rabbit Lake ores, 96 per cent from the Key Lake ore and 86 per cent from the Agnew Lake ore. However, tailings containing 15-20 pCi g -1 of radium-226 were obtained only from the Elliot Lake and Agnew lake quartz-pebble conglomerates and Bancroft pegmatite-type ores by second-stage leaches with HCl. The second-stage leach results indicate that multistage (3 or 4) acid-chloride or salt-chloride leaches might be effective to obtain tailings containing 15-20 pCi 226 Ra g -1 from the high-grade vein-type ores. Comparative reagent-cost estimates show that the sulphuric-acid leach process is far less expensive than aqueous chlorine leaching. Nevertheless, only the aqueous chlorine and acid-chloride leaches in stages are effective in producing tailings containing 15-20 pCi 226 Ra g -1 from the typical Canadian uranium ores. (Auth.)

Corrosion behaviour of borated aluminium used as neutron absorber

Energy Technology Data Exchange (ETDEWEB)

Emmerich, R. [EaglePicher Technologies GmbH, Oehringen (Germany); Ensinger, W.; Enders, B. [Philipps-Univ. of Marburg, Dept. of Chemistry, Material Science Centre (Germany)

2004-07-01

The electrochemical behaviour of pure and borated aluminium was examined. Measurements were performed in two different electrolytes at 90 C containing different trace-amounts of chloride. For borated aluminium current transients, i.e. metastable depassivation events were found. It is suggested to attribute these transients to less stable passivation layers in comparison to pure aluminium.

Effects of Aluminium Sulfate on Cadmium Accumulation in Rice

International Nuclear Information System (INIS)

Khamvarn, Vararas; Boontanon, Narin; Prapagdee, Benjaphorn; Kumsopa, Acharaporn; Boonsirichai, Kanokporn

2011-06-01

Full text: Cadmium accumulation in Pathum Thani 1 and Suphan Buri 60 rice cultivars was investigated upon treatment with aluminium sulfate as a precipitant. Rice was grown hydroponically in a medium containing 4 ppm cadmium nitrate with or without 4 ppm aluminium sulfate. Root, stem with leaves and grain samples were collected and analyzed for cadmium content using atomic absorption spectroscopy and inductively coupled plasma atomic emission spectroscopy. Without the addition of aluminium sulfate, Pathum Thani 1 and Suphan Buri 60 accumulated 24.71∫ 3.14 ppm and 34.43 ∫ 4.51 ppm (dry weight of whole plant) of cadmium, respectively. With aluminium sulfate, cadmium accumulation increased to 40.66 ∫ 2.47 ppm and 62.94 ∫ 10.69 ppm, respectively. The addition of aluminium sulfate to the planting medium did not reduce cadmium accumulation but caused the rice to accumulate more cadmium especially in the shoots and grains. This observation might serve as the basis for future research on the management of agricultural areas that are contaminated with cadmium and aluminium

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

International Nuclear Information System (INIS)

Biganzoli, Laura; Gorla, Leopoldo; Nessi, Simone; Grosso, Mario

2012-01-01

Highlights: ► Aluminium packaging partitioning in MSW incineration residues is evaluated. ► The amount of aluminium packaging recoverable from the bottom ashes is evaluated. ► Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. ► 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

Electron Conditioning of Technical Aluminium Surfaces

Energy Technology Data Exchange (ETDEWEB)

Le Pimpec, F

2004-09-02

The effect of electron conditioning on commercially aluminium alloys 1100 and 6063 were investigated. Contrary to the assumption that electron conditioning, if performed long enough, can reduce and stabilize the SEY to low values (= 1.3, value of many pure elements [1]), the SEY of aluminium did not go lower than 1.8. In fact, it reincreases with continued electron exposure dose.

Mineralogical and paragenetical problems of the Mecsek uranium ore

International Nuclear Information System (INIS)

Vincze, J.; Fazekas, V.

1979-01-01

The latest results of the ore-mineralogical examination of the uranium ore of a deposit included in Permian sandstones in the Mecsek Mountains, southern Hungary, are presented. The phases of the minerals belonging to the uranium oxide series and their types of development, the post-coffinite nasturan pseudomorphs and the relationship between nasturan and coffinite are dealt with. Of the sulphide ore minerals associated with uranium ore mineralization the type determinant mineral is pyrite, i.e. the mineral forming their bulk and partly represented by characteristically finely aggregated ''bacteriopyrite'' and/or spherical pyrite and ''framboidal pyrite. The textural pattern of the ore mineralization is of typically matrix type. The matrix of sandstone is constituted by carbonate minerals, ''hydromicas'' and ore minerals. The matrix and, consequently, the ore minerals will corrode and consume the allothigenic detrital rockforming minerals, the feldspar, quartz-porphyry and quartz. (A.L.)

Nanoscale Study of Clausthalite-Bearing Symplectites in Cu-Au-(U Ores: Implications for Ore Genesis

Directory of Open Access Journals (Sweden)

Nicholas D. Owen

2018-02-01

Full Text Available Symplectites comprising clausthalite (PbSe and host Cu-(Fe-sulphides (chalcocite, bornite, and chalcopyrite are instructive for constraining the genesis of Cu-Au-(U ores if adequately addressed at the nanoscale. The present study is carried out on samples representative of all three Cu-(Fe-sulphides displaying clausthalite inclusions that vary in size, from a few µm down to the nm-scale (<5 nm, as well as in morphology and inclusion density. A Transmission Electron Microscopy (TEM study was undertaken on foils prepared by Focussed Ion Beam and included atom-scale High-Angle Annular Dark-Field Scanning TEM (HAADF-STEM imaging. Emphasis is placed on phase relationships and their changes in speciation during cooling, as well as on boundaries between inclusions and host sulphide. Three species from the chalcocite group (Cu2–xS are identified as 6a digenite superstructure, monoclinic chalcocite, and djurleite. Bornite is represented by superstructures, of which 2a and 4a are discussed here, placing constraints for ore formation at T > 265 °C. A minimum temperature of 165 °C is considered for clausthalite-bearing symplectites from the relationships with antiphase boundaries in 6a digenite. The results show that alongside rods, blebs, and needle-like grains of clausthalite within the chalcocite that likely formed via exsolution, a second, overprinting set of replacement textures, extending down to the nanoscale, occurs and affects the primary symplectites. In addition, other reactions between pre-existing Se, present in solid solution within the Cu-(Fe-sulphides, and Pb, transported within a fluid phase, account for the formation of composite, commonly pore-attached PbSe and Bi-bearing nanoparticles within the chalcopyrite. The inferred reorganisation of PbSe nanoparticles into larger tetragonal superlattices represents a link between the solid solution and the symplectite formation and represents the first such example in natural materials

Radiometric enrichment of nonradioactive ores

International Nuclear Information System (INIS)

Mokrousov, V.A.; Lileev, V.A.

1979-01-01

Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

Chloride pyrometallurgy of uranium ore. 1. Chlorination of phosphate ore using solid or gas chlorinating agent and carbon

International Nuclear Information System (INIS)

Taki, Tomihiro; Komoto, Shigetoshi; Otomura, Keiichiro; Takenaka, Toshihide; Sato, Nobuaki; Fujino, Takeo.

1995-01-01

A thermodynamical and pyrometallurgical study to recover uranium from the phosphate ores was undertaken using the chloride volatilization method. Iron was chlorinated with solid chlorinating agents such as NaCl and CaCl 2 in combination with activated carbon, which will be used for removing this element from the ore, but uranium was not. On the other hand, the chlorination using Cl 2 gas and activated carbon gave a good result at 1,223 K. Not only uranium but also iron, phosphorus, aluminum and silicon were found to form volatile chlorides which vaporized out of the ore, while calcium remained in the ore as non-volatile CaCl 2 . The chlorination condition was studied as functions of temperature, reaction time and carbon content. The volatilization ratio of uranium around 95% was obtained by heating the mixture of the ore and activated carbon (35 wt%) in a mixed gas flow of Cl 2 (200 ml/min) and N 2 (200 ml/min) at 1,223 K for 120 min. (author)

Aluminium leaching from red mud by filamentous fungi.

Science.gov (United States)

Urík, Martin; Bujdoš, Marek; Milová-Žiaková, Barbora; Mikušová, Petra; Slovák, Marek; Matúš, Peter

2015-11-01

This contribution investigates the efficient and environmentally friendly aluminium leaching from red mud (bauxite residue) by 17 species of filamentous fungi. Bioleaching experiments were examined in batch cultures with the red mud in static, 7-day cultivation. The most efficient fungal strains in aluminium bioleaching were Penicillium crustosum G-140 and Aspergillus niger G-10. The A. niger G-10 strain was capable to extract up to approximately 141 mg·L(-1) of aluminium from 0.2 g dry weight red mud. Chemical leaching with organic acids mixture, prepared according to A. niger G-10 strain's respective fungal excretion during cultivation, proved that organic acids significantly contribute to aluminium solubilization from red mud. Copyright © 2015 Elsevier Inc. All rights reserved.

Determination of ultratrace amounts of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization/ICP-MS

International Nuclear Information System (INIS)

Nakamura, Yasushi; Kobayashi, Yoshio; Kakurai, Yousuke

1993-01-01

A method has been developed for determining the 0.01 ng g -1 level of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization (ETV)/ICP-MS. This method was found to be significantly interfered with any matrices or other elements contained. An ion-exchange technique was therefore applied to separate uranium and thorium from aluminium and other elements. It was known that uranium are adsorbed on an anion-exchange resin and thorium are adsorbed on cation-exchange resin. However, aluminium and copper were eluted with 6 M hydrochloric acid. Dissolve the sample with hydrochloric acid containing copper which was added for analysis of pure aluminium, and oxidize with hydrogen peroxide. Concentration of hydrochloric acid in the solution was adjusted to 6 M, and then passed the solution through the mixed ion-exchange resin column. After the uranium and thorium were eluted with 1 M hydrofluoric acid-0.1 M hydrochloric acid, the solution was evaporated to dryness. It was then dissolved with 1 M hydrochloric acid. Uranium and thorium were analyzed by ETV/ICP-MS using tungsten and molybdenum boats, respectively, since the tungsten boat contained high-level thorium and the molybdenum boat contained uranium. The determination limit of uranium and thorium were 0.003 and 0.005 ng g -1 , respectively. (author)

Investigations concerning the effect of aluminium toxicity on the physiology and fine structures of oat plants. Physiologische und feinstrukturelle Untersuchungen zur Aluminium-Toxizitaet an Haferpflanzen

Energy Technology Data Exchange (ETDEWEB)

Marienfeld, S.

1992-06-30

In order to test the toxicity of aluminium to plants, two-week-old oat seedlings were exposed to aluminium concentrations of 0-400 [mu]M in the culture broth. Already after 12-24 hours a decrease in longitudinal root growth is to be noted, resulting from impaired mitosis activity of the root tip. This, and the observed premature cell differentiation are not aluminium-specific but unspecific reactions to unfavourable conditions. Shoot growth is only reduced after 3-4 days, and less so. Magnesium and calcium fertilization did enhance the growth of aluminium-stressed plants, but not to the level of the control plants, although the mineral concentration in the leaves reached normal values. Phosphate concentration in the root increased because of aluminium phosphate precipitation in the cell walls, which has detoxifying effect along with aluminium fixation to negative charges in the cell walls. Aluminium remains almost quantitatively in the cell wall area of the roots and is not accumulated in the cell core. Aluminium stress causes transpiration and CO[sub 2] uptake to be impaired as a reaction to the growth depression in the root area, even before the mineral concentration in the shoots is lowered. Later there follow chlorophyll depletion, chloroplast degradation, and a reduction of the leaf area. (UWA)

Friction stir welding (FSW of aluminium foam sandwich panels

Directory of Open Access Journals (Sweden)

M. Bušić

2016-07-01

Full Text Available The article focuses on the influence of welding speed and tool tilt angle upon the mechanical properties at the friction stir welding of aluminium foam sandwich panels. Double side welding was used for producing butt welds of aluminium sandwich panels applying insertion of extruded aluminium profile. Such insertion provided lower pressure of the tool upon the aluminium panels, providing also sufficient volume of the material required for the weldment formation. Ultimate tensile strength and flexural strength for three-point bending test have been determined for samples taken from the welded joints. Results have confirmed anticipated effects of independent variables.

Surface treatments for aluminium alloys

Science.gov (United States)

Ardelean, M.; Lascău, S.; Ardelean, E.; Josan, A.

2018-01-01

Typically, in contact with the atmosphere, the aluminium surface is covered with an aluminium oxide layer, with a thickness of less than 1-2μm. Due to its low thickness, high porosity and low mechanical strength, this layer does not protect the metal from corrosion. Anodizing for protective and decorative purposes is the most common method of superficial oxidation processes and is carried out through anodic oxidation. The oxide films, resulted from anodizing, are porous, have a thickness of 20-50μm, and are heat-resistant, stable to water vapour and other corrosion agents. Hard anodizing complies with the same obtains principles as well as decorative and protective anodization. The difference is in that hard anodizing is achieved at low temperatures and high intensity of electric current. In the paper are presented the results of decorative and hard anodization for specimens made from several aluminium alloys in terms of the appearance of the specimens and of the thickness of the anodized.

Accumulation of Aluminium and Physiological Status of Tree Foliage in the Vicinity of a Large Aluminium Smelter

Directory of Open Access Journals (Sweden)

E. D. Wannaz

2012-01-01

Full Text Available A pollution gradient was observed in tree foliage sampled in the vicinity of a large aluminium production facility in Patagonia (Argentina. Leaves of Eucalyptus rostrata, and Populus hybridus and different needle ages of Pinus spec. were collected and concentrations of aluminium (Al and sulphur (S as well as physiological parameters (chlorophyll and lipid oxidation products were analyzed. Al and S concentrations indicate a steep pollution gradient in the study showing a relationship with the physiological parameters in particular membrane lipid oxidation products. The present study confirms that aluminium smelting results in high Al and sulphur deposition in the study area, and therefore further studies should be carried out taking into account potentially adverse effects of these compounds on human and ecosystem health.

Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

Directory of Open Access Journals (Sweden)

Rakesh Kumar

2016-07-01

Full Text Available Aluminium and iron are widely used in construction sectors for the preparation of advanced composites with epoxy resins as matrices. In recent times, there are several reports on the polymerization of polyfufuryl alcohol (PFA a thermoset bioresins from furfuryl alcohol (FA. FA is obtained from waste of sugarcane bagasse. In this work, first the possibility of curing PFA from FA in the presence of aluminium or iron has been explored. Absorbance results from colorimeter/spectrophotometerindicated that the curing of FA to PFA in presence of aluminium started easily while in presence of iron the curing of FA to PFA could not start. Based on the above results, aluminium wire reinforced composites were successfully prepared with three different weight fractions (0.13, 0.09 and 0.07 of aluminium wire. The mechanical properties of these composites were determined theoretically and reported.

Ore reserve estimation of uranium deposit Zirovski vrh

International Nuclear Information System (INIS)

Lukacs, E.

1979-01-01

The uranium ore deposit Zirovski vrh is in the Permian sediments of Northwest Yugoslavia. Lenticular bodies occur at several stratiform levels in grey, medium-grained sandstone. The ore deposit will be mined entirely by underground methods. It is possible to define three stages of deposit evaluation requiring different densities of exploration effort: preliminary evaluation of in situ ore reserves; evaluation of mineable ore reserves; evaluation of production capability and mine planning. The drilling density increases markedly with each succeeding stage. The optimal drilling density for all three stages of evaluation should be determined, but there is some concern that too close spaced drilling would considerably increase the exploration costs without a corresponding increase in effectiveness. On the other hand, too sparsely spaced drilling may result in some difficulties in following the ore in mining. The paper treats the problem of the density of drilling for evaluation of mineable ore reserves compared to that required for mine planning and mine production capability. The purpose of investigation of mineral raw materials is to define economic deposits (ore bodies). To evaluate the deposit economically an accurate reserve estimate is required. If it is accordingly established that such an estimate is within the degree of admissible error, the purpose of the exploration is satisfied. However, the problem as to whether the drilling grid is sufficiently dense remains, because the majority of estimates of ore reserves do not provide a measure of the reliability of the estimate. (author)

Modelling a uranium ore bioleaching process

International Nuclear Information System (INIS)

Chien, D.C.H.; Douglas, P.L.; Herman, D.H.; Marchbank, A.

1990-01-01

A dynamic simulation model for the bioleaching of uranium ore in a stope leaching process has been developed. The model incorporates design and operating conditions, reaction kinetics enhanced by Thiobacillus ferroxidans present in the leaching solution and transport properties. Model predictions agree well with experimental data with an average deviation of about ± 3%. The model is sensitive to small errors in the estimates of fragment size and ore grade. Because accurate estimates are difficult to obtain a parameter estimation approach was developed to update the value of fragment size and ore grade using on-line plant information

Geology of eastern Smith Lake ore trend, Grants mineral belt

International Nuclear Information System (INIS)

Ristorcelli, S.J.

1980-01-01

The sandstones in the Brushy Basin Member of the Morrison Formation (Jurassic) are the ore-bearing horizons of the eastern Smith Lake area. The Brushy Basin Member in this district consists of three sandstones with interbedded mudstones. Only the lower two sandstones contain ore. The sandstones are fine to coarse grained, well rounded, and arkosic, representing continental stream sediments. The lower sandstone contains rollfront ore. The redox interface is laterally extensive and well defined, extending at least 7 mi (11 km) west of the Bluewater fault zone. The ore generally occurs at the redox boundary but occasionally will be up to 1500 ft (450 m) updip. Limonitic alteration, where present, is downdip from the hematitic zone and is 100-1,500 ft (30 to 450 m) wide. The middle sandstone contains both trend ore and roll-front ore. The trend ore occurs downdip from the redox front in unoxidized ground. The redox front in the middle sand is also laterally extensive but displays a wedge shape, rather than a C shape. The clay assemblages of the two types of ore are different: the trend ore occurs in sands with the pore spaces filled with kaolinite; the roll-front ore is associated with altered illite-montmorillonite as grain coatings. Hematitic alteration is asociated with the latter. A second stage of kaolinite coats the illite-montmorillonite. Two periods of mineralization are suggested, but no absolute dates are known. The trend ore is the oldest (Jurassic) and is similar to the ore found in unoxidized ground elsewhere in the Grants region. The rollfront ore could be Laramide or post-Laramide because of its association with local Laramide structures

Volatilisation and oxidation of aluminium scraps fed into incineration furnaces

Energy Technology Data Exchange (ETDEWEB)

Biganzoli, Laura, E-mail: laura.biganzoli@mail.polimi.it [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy); Gorla, Leopoldo; Nessi, Simone; Grosso, Mario [Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Aluminium packaging partitioning in MSW incineration residues is evaluated. Black-Right-Pointing-Pointer The amount of aluminium packaging recoverable from the bottom ashes is evaluated. Black-Right-Pointing-Pointer Aluminium packaging oxidation rate in the residues of MSW incineration is evaluated. Black-Right-Pointing-Pointer 80% of aluminium cans, 51% of trays and 27% of foils can be recovered from bottom ashes. - Abstract: Ferrous and non-ferrous metal scraps are increasingly recovered from municipal solid waste incineration bottom ash and used in the production of secondary steel and aluminium. However, during the incineration process, metal scraps contained in the waste undergo volatilisation and oxidation processes, which determine a loss of their recoverable mass. The present paper evaluates the behaviour of different types of aluminium packaging materials in a full-scale waste to energy plant during standard operation. Their partitioning and oxidation level in the residues of the incineration process are evaluated, together with the amount of potentially recoverable aluminium. About 80% of post-consumer cans, 51% of trays and 27% of foils can be recovered through an advanced treatment of bottom ash combined with a melting process in the saline furnace for the production of secondary aluminium. The residual amount of aluminium concentrates in the fly ash or in the fine fraction of the bottom ash and its recovery is virtually impossible using the current eddy current separation technology. The average oxidation levels of the aluminium in the residues of the incineration process is equal to 9.2% for cans, 17.4% for trays and 58.8% for foils. The differences between the tested packaging materials are related to their thickness, mechanical strength and to the alloy.

Aluminium allergy and granulomas induced by vaccinations for children

DEFF Research Database (Denmark)

Andersen, Rosa Marie O; Zachariae, Claus; Johansen, Jeanne Duus

2014-01-01

Vaccination with aluminium-adsorbed vaccines can induce aluminium allergy with persistent itching subcutaneous nodules at the injection site - vaccination granulomas. In this article we give an overview of childhood aluminium-adsorbed vaccines available in Denmark. Through literature studies we...... examine the incidence, the symptoms and the prognosis for the vaccination granulomas and the allergy. Finally we discuss the status in Denmark....

Discussion on uranium ore-formation age in Xiazhuang ore-field, northern Guangdong

International Nuclear Information System (INIS)

Wu Lieqin; Tan Zhengzhong; Liu Ruzhou; Huang Guolong

2003-01-01

There exist two genetic types of granite-type uranium deposits, i.e. the early-stage one, and the late-stage one. The early-stage uranium deposits are characterized by ore-formation ages of 122-138 Ma, and are high-grade uranium deposits of postmagmatic hydrothermal origin. The late-stage uranium deposits have ore-formation ages of 54-96 Ma. They mostly are low-grade uranium deposits, and of hydrothermal-regeneration origin with the uranium source derived from the mobilization of consolidated rocks. The early-stage uranium deposits should be the main target of further prospecting for high-grade uranium deposits in the region

Hot workability of aluminium alloys

International Nuclear Information System (INIS)

Yoo, Yeon Chul; Oh, Kyung Jin

1986-01-01

Hot Workability of aluminium alloys, 2024, 6061 and 7075, has been studied by hot torsion tests at temperatures from 320 to 515 deg C and at strain rates from 1.26 x 10 -3 to 5.71 x 10 -3 sec -1 . Hot working condition of these aluminium alloys was determined quantitatively from the constitutive equations obtained from flow stress curves in torsion. Experimental data of the logarith of the Zener-Hollomonn parameter showed good linear relationships to the logarith of sinh(ασ-bar)

Computer finds ore

Science.gov (United States)

Bell, Peter M.

Artificial intelligence techniques are being used for the first time to evaluate geophysical, geochemical, and geologic data and theory in order to locate ore deposits. After several years of development, an intelligent computer code has been formulated and applied to the Mount Tolman area in Washington state. In a project funded by the United States Geological Survey and the National Science Foundation a set of computer programs, under the general title Prospector, was used successfully to locate a previously unknown ore-grade porphyry molybdenum deposit in the vicinity of Mount Tolman (Science, Sept. 3, 1982).The general area of the deposit had been known to contain exposures of porphyry mineralization. Between 1964 and 1978, exploration surveys had been run by the Bear Creek Mining Company, and later exploration was done in the area by the Amax Corporation. Some of the geophysical data and geochemical and other prospecting surveys were incorporated into the programs, and mine exploration specialists contributed to a set of rules for Prospector. The rules were encoded as ‘inference networks’ to form the ‘expert system’ on which the artificial intelligence codes were based. The molybdenum ore deposit discovered by the test is large, located subsurface, and has an areal extent of more than 18 km2.

Aluminium toxicity tolerance in crop plants: Present status of research

African Journals Online (AJOL)

... tolerance of which genes of the Aluminium-activated malate transporter (ALMT) and multidrug and toxic compound extrusion (MATE) families are prominent. In this review, the progress of research in identifying aluminium toxicity tolerant genes is discussed. Keywords: Aluminium toxicity, soil acidity, hydroponic screening, ...

Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance; Les sulfates phosphates d'aluminium hydrates (APS) dans l'environnement des gisements d'uranium associes a une discordance proterozoique: caracterisation cristallochimique et signification petrogenetique

Energy Technology Data Exchange (ETDEWEB)

Gaboreau, St

2005-07-01

Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO{sub 2} and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit

Directory of Open Access Journals (Sweden)

Seyyed Ali Nezamolhosseini

2017-01-01

Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone.  Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.

Compressive Behaviour and Energy Absorption of Aluminium Foam Sandwich

Science.gov (United States)

Endut, N. A.; Hazza, M. H. F. Al; Sidek, A. A.; Adesta, E. T. Y.; Ibrahim, N. A.

2018-01-01

Development of materials in automotive industries plays an important role in order to retain the safety, performance and cost. Metal foams are one of the idea to evolve new material in automotive industries since it can absorb energy when it deformed and good for crash management. Recently, new technology had been introduced to replace metallic foam by using aluminium foam sandwich (AFS) due to lightweight and high energy absorption behaviour. Therefore, this paper provides reliable data that can be used to analyze the energy absorption behaviour of aluminium foam sandwich by conducting experimental work which is compression test. Six experiments of the compression test were carried out to analyze the stress-strain relationship in terms of energy absorption behavior. The effects of input variables include varying the thickness of aluminium foam core and aluminium sheets on energy absorption behavior were evaluated comprehensively. Stress-strain relationship curves was used for energy absorption of aluminium foam sandwich calculation. The result highlights that the energy absorption of aluminium foam sandwich increases from 12.74 J to 64.42 J respectively with increasing the foam and skin thickness.

Investigation of different anode materials for aluminium rechargeable batteries

Science.gov (United States)

Muñoz-Torrero, David; Leung, Puiki; García-Quismondo, Enrique; Ventosa, Edgar; Anderson, Marc; Palma, Jesús; Marcilla, Rebeca

2018-01-01

In order to shed some light into the importance of the anodic reaction in reversible aluminium batteries, we investigate here the electrodeposition of aluminium in an ionic liquid electrolyte (BMImCl-AlCl3) using different substrates. We explore the influence of the type of anodic material (aluminium, stainless steel and carbon) and its 3D geometry on the reversibility of the anodic reaction by cyclic voltammetry (CV) and galvanostatic charge-discharge. The shape of the CVs confirms that electrodeposition of aluminium was feasible in the three materials but the highest peak currents and smallest peak separation in the CV of the aluminium anode suggested that this material was the most promising. Interestingly, carbon-based substrates appeared as an interesting alternative due to the high peak currents in CV, moderate overpotentials and dual role as anode and cathode. 3D substrates such as fiber-based carbon paper and aluminium mesh showed significantly smaller overpotentials and higher efficiencies for Al reaction suggesting that the use of 3D substrates in full batteries might result in enhanced power. This is corroborated by polarization testing of full Al-batteries.

Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

Energy Technology Data Exchange (ETDEWEB)

Prabhat Tripathy; Laura Wurth; Eric Dufek; Toni Y. Gutknecht; Natalie Gese; Paula Hahn; Steven Frank; Guy Fredrickson; J Stephen Herring

2014-08-01

A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

Characterisation and concentration profile of aluminium during ...

African Journals Online (AJOL)

An aluminium(Al) characterisation study was conducted at a surface water treatment plant (Buffalo Pound Water Treatment Plant (BPWTP) in Moose Jaw, Saskatchewan, Canada) to understand better the effect of alum coagulant on various Al fractions. The raw water source for BPWTP is Buffalo Pound Lake water. The Al ...

Feet sunk in molten aluminium: The burn and its prevention.

Science.gov (United States)

Alonso-Peña, David; Arnáiz-García, María Elena; Valero-Gasalla, Javier Luis; Arnáiz-García, Ana María; Campillo-Campaña, Ramón; Alonso-Peña, Javier; González-Santos, Jose María; Fernández-Díaz, Alaska Leonor; Arnáiz, Javier

2015-08-01

Nowadays, despite improvements in safety rules and inspections in the metal industry, foundry workers are not free from burn accidents. Injuries caused by molten metals include burns secondary to molten iron, aluminium, zinc, copper, brass, bronze, manganese, lead and steel. Molten aluminium is one of the most common causative agents of burns (60%); however, only a few publications exist concerning injuries from molten aluminium. The main mechanisms of lesion from molten aluminium include direct contact of the molten metal with the skin or through safety apparel, or when the metal splash burns through the pants and rolls downward along the leg. Herein, we report three cases of deep dermal burns after 'soaking' the foot in liquid aluminium and its evolutive features. This paper aims to show our experience in the management of burns due to molten aluminium. We describe the current management principles and the key features of injury prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

The physical hydrogeology of ore deposits

Science.gov (United States)

Ingebritsen, Steven E.; Appold, M.S.

2012-01-01

Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

Directory of Open Access Journals (Sweden)

B. Bobic

2010-03-01

Full Text Available The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion was discussed. Some corrosion protection methods of aluminium based MMCs were described

Cold forming of aluminium - State of the art

DEFF Research Database (Denmark)

Bay, Niels

1997-01-01

The ongoing development of cold forging technology has been manifested lately by the increasing application of components in cold forged aluminium alloys. Applying precipitation hardening alloys components with great strength/weight ratio can be produced with a strength comparable...... to that of unalloyed steel. After description of the different types of alloys and their individual properties and applications, the special requirements for tool design by cold forging in aluminium is discussed. Finally, a large number of industrial examples on cold forged aluminium components are presented. (C) 1997...

Effect of pressurized steam on AA1050 aluminium

DEFF Research Database (Denmark)

Jariyaboon, Manthana; Møller, Per; Ambat, Rajan

2012-01-01

Purpose - The purpose of this paper is to understand the effect of pressurized steam on surface changes, structures of intermetallic particles and corrosion behavior of AA1050 aluminium. Design/methodology/approach - Industrially pure aluminium (AA1050, 99.5 per cent) surfaces were exposed...... reactivities was observed due to the formation of the compact oxide layer. Originality/value - This paper reveals a detailed investigation of how pressurized steam can affect the corrosion behaviour of AA1050 aluminium and the structure of Fe-containing intermetallic particles....

Characterization of aluminium alloys rapidly solidified

International Nuclear Information System (INIS)

Monteiro, W.A.

1988-01-01

This paper discussed the investigation of the microstructural and mechanical properties of the aluminium alloys (3003; 7050; Al-9% Mg) rapidly solidified by melt spinning process (cooling rate 10 4 - 10 6 K/s). The rapidly solidification process of the studied aluminium alloys brought a microcrystallinity, a minimum presence of coarse precipitation and, also, better mechanical properties of them comparing to the same alloys using ingot process. (author) [pt

Sinter aluminium as cladding material for fuel elements; Aluminium fritte comme materiau de gainage pour les elements combustibles

Energy Technology Data Exchange (ETDEWEB)

Mann, K E; Boudouresques, M B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Otto Fuchs, Meinerzhagen, Westfalen (Germany)

1961-07-01

1. Survey of the production process of sinter aluminium. 2. Description of the forming processes (extrusion, forging and rolling), whereby the production of tubing for atom piles will be explained in detail. 3. Production of ribbed tubes and tubes with close tolerances of sizes. 4. The different SAP-qualities and their properties under special consideration of the properties at elevated temperatures and the creep properties. 5. Diffusion behaviour of SAP with Be, Mg, Al, U and UO{sub 2}. 6. Corrosion behaviour in CO{sub 2} atmosphere at high temperature and in water. 7. Weldability. 8. Effect of irradiation on the mechanical properties. 9. Superiority of SAP compared with normal wrought alloys of the same composition. (author) [French] 1. Apercu des processus de production de l'aluminium fritte. 2. Expose des operations de transformation (filageries, forgeage et laminage), avec explication detaillee de la fabrication de gaine pour reacteurs. 3. Fabrication de tubes canneles et de tubes avec de faibles tolerances. 4. Diverses proprietes de l'aluminium fritte SAP, notamment proprietes aux temperatures elevees et proprietes de fluage. 5. Diffusion de l'aluminium fritte SAP en presence de Be, Mg, Al, U et UO{sub 2}. 6. Resistance a la corrosion dans une atmosphere de CO{sub 2} a temperature elevee et dans l'eau. 7. Possibilites de soudage. 8. Effet de l'irradiation sur les proprietes mecaniques. 9. Superiorite de l'aluminium fritte SAP sur les alliages forges normaux de meme composition. (auteur)

Low temperature oxidation of niobium alloy with silicon-aluminium coating

International Nuclear Information System (INIS)

Lazarev, Eh.M.; Sapozhnikova, L.V.; Shabanova, M.E.; Pod'yachev, V.N.; Kornilova, Z.I.

1987-01-01

Using the gravimetry methods heat resistance of niobium-titanium-aluminium alloy in the air and at 700 deg C in the initial state and when it is protected by silicide-aluminium coatings (with variable content of aluminium) is investigated. Using X-ray diffraction and micro X-ray diffraction analyses, mechanisms of the alloy oxidation and the coating protective effect are studied. The role of aluminium in the formation of coatings is analyzed and according to bend tests the plasticity of the coatings is evaluated

Acid pre-treatment method for in situ ore leaching

International Nuclear Information System (INIS)

Mallon, R.G.; Braun, R.L.

1975-01-01

An acid leaching method is described for the recovery of a desired element from a subterranean rubblized body of primary ore containing the element and also having associated therewith a carbonate mineral wherein the rubblized ore body is flooded with an aqueous acidic solution in order to release carbon dioxide from the associated carbonate mineral. After a substantial portion of the available carbon dioxide is released and removed from the ore body, as by venting to the atmosphere, an oxidizing gas is introduced into the flooded, rubblized ore to oxidize the ore and form an acid leach solution effective in the presence of the dissolved oxidizing gas to dissolve the ore and cause the desired element to go into solution. The leach solution is then circulated to the surface where the metal values are recovered therefrom

The structure of high-quality aluminium cast iron

Directory of Open Access Journals (Sweden)

D. Kopyciński

2012-01-01

Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

Characteristics of sandstone-type uranium mineralization and ore-controlling factors in Wukurqi ore district at southern margin of Yili basin, Xinjiang

International Nuclear Information System (INIS)

Li Xigen

2002-01-01

With the theories of hydrogenic uranium deposit in the nineties, Wukurqi ore district as a new area was found by the regional prediction and prospecting. Specially, through uranium ore prospecting of about three years, certain prospective reserves are generally controlled in the area. These reserves are hosted in V cyclothem of Middle-Lower Jurassic series, and some prospective reserves are hosted in II and VII cyclothems. By analyzing and summarizing characteristics of sandstone-type uranium mineralization and its ore-controlling factors in Wukurqi ore district, the author provides a foundation for developing further prospecting in this area

Method of preparing an Al-Ti-B grain refiner for aluminium-comprising products, and a method of casting aluminium products

NARCIS (Netherlands)

Brinkman, H.J.; Duszczyk, J.; Katgerman, L.

1999-01-01

The invention relates to a method of preparing an Al-Ti-B grain refiner for cast aluminium-comprising products. According to the invention the preparation is realized by mixing powders selected from the group comprising aluminium, titanium, boron, and alloys and intermetallic compounds thereof,

Summary of the mineralogy of the Colorado Plateau uranium ores

Science.gov (United States)

Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

1956-01-01

In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

Recovery of tritium from lithium-sintered aluminium product (SAP) and lithium-aluminium alloys

International Nuclear Information System (INIS)

Talbot, J.B.; Wiffen, F.W.

1979-01-01

The tritium release rates of irradiated samples of lithium-containing aluminium (Li-Al) and sintered aluminium product (Li-SAP) were investigated to evaluate the potential application of both materials in fusion reactors. The observed release rates followed the pattern expected for bulk diffusion of tritium in a solid. Therefore, diffusion coefficients for tritium in Li-SAP were determined over a temperature range of 383 and 500 0 C and tritium in Li-Al at 450 0 C. At 450 0 C, the diffusion coefficients of tritium in Li-SAP and Li-Al are 2.988 x 10 -10 cm 2 sec -1 and 1.462 x 10 -6 cm 2 sec -1 , respectively. (author)

Composite correlation filter for O-ring detection in stationary colored noise

Science.gov (United States)

Hassebrook, Laurence G.

2009-04-01

O-rings are regularly replaced in aircraft and if they are not replaced or if they are installed improperly, they can result in catastrophic failure of the aircraft. It is critical that the o-rings be packaged correctly to avoid mistakes made by technicians during routine maintenance. For this reason, fines may be imposed on the o-ring manufacturer if the o-rings are packaged incorrectly. That is, a single o-ring must be packaged and labeled properly. No o-rings or more than one o-ring per package is not acceptable. We present an industrial inspection system based on real-time composite correlation filtering that has successfully solved this problem in spite of opaque paper o-ring packages. We present the system design including the composite filter design.

Thermal formation of corundum from aluminium hydroxides ...

Indian Academy of Sciences (India)

Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form -Al2O3 at ∼ 400°C but the formation of -Al2O3 at 1200°C occurs more readily in the material derived ...

Thermal formation of corundum from aluminium hydroxides ...

Indian Academy of Sciences (India)

Abstract. Aluminium hydroxides have been precipitated from various aluminium salts and the differences in their thermal behaviour have been investigated. Pseudoboehmite derived from the nitrate, sulfate and chloride all form γ-Al2O3 at ~ 400°C but the formation of α-Al2O3 at 1200°C occurs more readily in the material ...

Influence of Alkali Treatment on the Surface Area of Aluminium Dross

Directory of Open Access Journals (Sweden)

N. S. Ahmad Zauzi

2016-01-01

Full Text Available Aluminium dross is an industrial waste from aluminium refining industry and classified as toxic substances. However, the disposal of dross as a waste is a burden to aluminium manufacturer industries due to its negative effects to the ecosystem, surface, and ground water. Therefore the purpose of this study is to evaluate the influence of sodium hydroxide (NaOH on the surface area and pore size of aluminium dross. There were 3 stages in the treatment activities, which were leaching, precipitation, and calcination process. The optimum result from this study was the surface area of aluminium dross increases from 10.1 m2/g up to 80.0 m2/g at 40°C, 1% NaOH, and 15-minute reaction time. Thus, aluminium dross has a potential to be converted into other useful material such as catalyst and absorbent. The benefit of this research is that the hazardous industrial waste can be turned into wealth to be used in other applications such as in catalytic activities and absorber in waste water treatment. Further investigation on the physicochemical of aluminium dross with different acid or alkali should be conducted to get deeper understanding on the aluminium dross as a catalyst-type material.

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

Energy Technology Data Exchange (ETDEWEB)

Mouturat, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete considerablement reduite par des conditions

The binding, transport and fate of aluminium in biological cells.

Science.gov (United States)

Exley, Christopher; Mold, Matthew J

2015-04-01

Aluminium is the most abundant metal in the Earth's crust and yet, paradoxically, it has no known biological function. Aluminium is biochemically reactive, it is simply that it is not required for any essential process in extant biota. There is evidence neither of element-specific nor evolutionarily conserved aluminium biochemistry. This means that there are no ligands or chaperones which are specific to its transport, there are no transporters or channels to selectively facilitate its passage across membranes, there are no intracellular storage proteins to aid its cellular homeostasis and there are no pathways which evolved to enable the metabolism and excretion of aluminium. Of course, aluminium is found in every compartment of every cell of every organism, from virus through to Man. Herein we have investigated each of the 'silent' pathways and metabolic events which together constitute a form of aluminium homeostasis in biota, identifying and evaluating as far as is possible what is known and, equally importantly, what is unknown about its uptake, transport, storage and excretion. Copyright © 2014 Elsevier GmbH. All rights reserved.

Ore potential of basic rocks in Finland

International Nuclear Information System (INIS)

Reino, J.; Ekberg, M.; Heinonen, P.; Karppanen, T.; Hakapaeae, A.; Sandberg, E.

1993-02-01

The report is associated with a study programme on basic rocks, which has the aim to complement the preliminary site investigations on repository for TVO's (Teollisuuden Voima Oy) spent nuclear fuel. The report comprises a mining enterprise's view of the ore potential of basic plutonic rocks in Finland. The ores associated with basic plutonic rocks are globally known and constitute a significant share of the global mining industry. The ores comprise chromium, vanadium-titanium-iron, nickel-copper and platinum group element ores. The resources of the metals in question and their mining industry are examined globally. A review of the use of these metals in the industry is presented as well. General factors affecting the mining industry, such as metal prices, political conjunctures, transport facilities, environmental requirements and raw material sources for the Finnish smelters have been observed from the point of view of their future effect on exploration activity and industrial development in Finland. Information on ores and mineralizations associated with Finnish basic rocks have been compiled in the report. The file comprises 4 chromium occurrences, 8 vanadium-titanium-iron occurrences, 13 PGE occurrences and 38 nickel-copper occurrences

Testing of X-ray radiometric enrichnment of polymetallic ores

International Nuclear Information System (INIS)

Eliseev, N.I.; Panova, N.I.; Kirbitova, N.V.; Shramm, E.O.; Efremov, Yu.G.

1987-01-01

Testing of X-ray radiometric method of sorting of polymetallic ores using the developed X-ray radiometric device was conducted. It was shown that introduction of preliminary concentration at the factory made the method of fragment separation to be the perspective one, enabling to elevate the factory production with respect to commercial ore and reduce the cost of ore processing. In the case of preliminary concentration, conducted at the mine, it is advisable to perform ore sorting in the flow formed to monolayer

X-ray fluorescence separation of pure lead-zinc ores

International Nuclear Information System (INIS)

Lapshin, S.A.; Filippov, O.K.; Khachatryan, L.S.; Rudnev, B.P.

1987-01-01

To evaluate the influence of the previous concentration of polymetallic ores by the radiometric separation method on indices of flotation and gravitation enrichments, investigations were carried out using ore sample (1.94%Pb, 1.13% Zn) from a lead-zink ore deposit. It is shown that the results obtained on the enrichment of the ore and products of X-ray radiometric separation are similar. However previous removal (up to 40%) of dead rock permits to reduce sharply grinding and transpot costs

Wear and chemistry of zirconium-silicate, aluminium-silicate and zirconium-aluminium-silicate glasses in alkaline medium

International Nuclear Information System (INIS)

Rouse, C.G.; Lemos Guenaga, C.M. de

1984-01-01

A study of the chemical durability, in alkaline solutions, of zirconium silicate, aluminium silicate, zirconium/aluminium silicate glasses as a function of glass composition is carried out. The glasses were tested using standard DIN-52322 method, where the glass samples are prepared in small polished pieces and attacked for 3 hours in a 800 ml solution of 1N (NaOH + NA 2 CO 3 ) at 97 0 C. The results show that the presence of ZrO 2 in the glass composition increases its chemical durability to alkaline attack. Glasses of the aluminium/zirconium silicate series were melted with and without TiO 2 . It was shown experimentally that for this series of glasses, the presence of both TiO 2 and ZrO 2 gave better chemical durability results. However, the best overall results were obtained from the simpler zirconium silicate glasses, where it was possible to make glasses with higher values of ZrO 2 . (Author) [pt

Aluminium effect on the physical properties of titanium

International Nuclear Information System (INIS)

Nazimov, O.P.; Il'in, A.A.; Zvonova, L.N.

1977-01-01

The effect of aluminium on the physical properties of titanium was investigated. Within the framework of the configuration model of matter it is shown that a change in physical properties with an aluminium content of up to 7.5 wt.% in alloys depends on the phase composition and electron structure. In interacting with titanium, aluminium exhibits acceptor properties, causing d→s electron transitions. The electrons which have shifted to the s-state are partly collectivized and partly localized into quasistable sp 3 configurations, with the resulting increase of the interatomic forces. An intensification of d→s transitions in alloying of titanium with aluminium stabilizes the α-phase. Predominance of d 1 configurations in the intermediate spectrum in the region of the α-solution increases the ratio of the axes of the HCP lattice and determines the electron type of conduction of alloys of the Ti-Al system

Aluminium and Aroma Compound Concentration in Beer During Storage at Different Temperatures

Directory of Open Access Journals (Sweden)

Marija Soldo Gjeldum

2006-01-01

Full Text Available Problem of aluminium in beer has been elaborated in several papers over the last decade. However, the effect of aluminium on organoleptic properties of beer has been observed in few papers where it has been stated that aluminium gives beer a »metallic« and bitter flavour without any observations on particular aroma compound changes. Also, the number of reports on precise changes of aroma components throughout different storage conditions is surprisingly scarce. In order to investigate the changes of aluminium concentration along with aroma compound changes, graphite furnace-atomic absorption spectrophotometry (GF-AAS with Zeeman background correction and gas chromatography with static headspace sampler (GC-HSS were used in this work. Analyses were conducted periodically throughout seven months of storage on three different brands of beer from name breweries. Samples were taken before and after filling in aluminium cans. One part of samples was stored in a refrigerator (4 °C and the other in a thermostatic chamber (22 °C. The effects of beer brand and storage conditions on aluminium concentration and level of aroma compounds were measured. To prove the effect of aluminium concentration on the changes of aroma compounds, the adequate level of aluminium sulphate was added to bottled beer samples stored at 28 °C. Although different beer types showed significantly different aluminium concentration, it could be the result of other factors (different batches of identical beer type showed significantly different aluminium concentration as well. Samples that were stored in the refrigerator were protected from aluminium migration from the can to the beer and showed increased aroma stability. Level of aroma constituents of analyzed beer brands was significantly different. Elevated aluminium concentration did not have any noticeable effect on the level of aroma compounds in beer samples stored at 28 °C.

Experimental Realisation of Elusive Multiple-bonded Aluminium Compounds: A New Horizon in the Aluminium Chemistry.

Science.gov (United States)

Inoue, Shigeyoshi; Bag, Prasenjit; Weetman, Catherine

2018-05-23

Synthesis and isolation of stable main group compounds featuring multiple bonds has been of keen interest for the last several decades. Multiply bonded complexes were obtained using sterically demanding substituents that provide kinetic and thermodynamic stability. Many of these compounds have unusual structural and electronic properties that challenges the classical concept of covalent multiple bonding. In contrast, analogous aluminium compounds are scarce in spite of its high natural abundance. The parent dialumene (Al2H2) has been calculated to be extremely weak, thus making Al multiple bonds a challenging synthetic target. This review provides an overview of these recent advances in the cutting edge synthetic approaches used to obtain aluminium homo- and heterodiatomic multiply bonded complexes. Additionally, the reactivity of these novel compounds towards various small molecules and reagents will be discussed herein. This review provides an overview on the current progress in aluminium multiple bond chemistry and the careful ligand design required to stabilise these reactive species. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-column bioleaching of a uranium ore

International Nuclear Information System (INIS)

Meng Yunsheng; Zheng Ying; Liu Hui; Cheng Hao

2014-01-01

The technology of bioleaching uranium ore can increase the uranium leaching rate and shorten the leaching uranium period, save consumption of acid and oxidant, lower production costs. An experiment on multi-column bioleaching of a uranium ore was done using mesophilic bacteria, the average uranium recovery of 90% was achieved in 39 days. Compared with traditional process, leaching period was shortened to 39 d from 59 d, acid consumption and liquid-solid ratio were also reduced. The results showed it is suitable to bioleach the uranium ore. (authors)

Iron from Zealandic bog iron ore -

DEFF Research Database (Denmark)

Lyngstrøm, Henriette Syrach

2011-01-01

og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

Sintered aluminium powders

International Nuclear Information System (INIS)

Stepanova, M.G.; Matveev, B.I.

1974-01-01

The mechanical and physical properties of aluminium powder alloys and the various methods employed to produce them are considered. Data are given on the hardening of the alloys SAP and SPAK-4, as well as the powder-alloy system Al-Cr-Zr. (L.M.)

Methods of evaluating ore processing and effluent treatment for Cigar Lake ore at the Rabbit Lake Mill

International Nuclear Information System (INIS)

Edwards, C.R.

2002-01-01

Cigar Lake is the second-largest, high grade uranium orebody in the world. Mineable reserves for Cigar Lake Phase 1 are estimated at 191 million pounds U 3 O 8 with a grade of 25.6% U 3 O 8 . Subject to regulatory approval, Cameco intends to process the majority of ore from Cigar Lake in the Rabbit Lake mill. Cameco initiated a programme to study the processing of Cigar Lake ore and the treatment of the resulting waste streams. Laboratory and follow-up pilot scale ore leaching tests with Cigar Lake ore samples were performed. Tailings and effluents were generated from the products of the pilot scale leach tests. Mill process tailings were blended with ground waste rock. Using these materials, geotechnical and geochemical properties, including long term tailings pore water characteristics, will be evaluated. In addition, proposed changes to the mill waste treatment operations were developed to deal with increased levels of arsenic and radium in the waste streams. This paper describes the methods and techniques Cameco used in this programme. (author)

Silane based coating of aluminium mold

DEFF Research Database (Denmark)

2013-01-01

having at least one closed cavity is provided, at least one surface of the at least one cavity being an aluminium surface coated with a silane based coating layer. The silane based anti-stiction coating improves the anti-stiction properties of the mold which may allow for molding and demolding...... of structures which would otherwise be difficult to mold. The resistance of the coated aluminium mold is significantly improved by applying a silane-based coating layer....

Aluminium hydroxide-induced granulomas in pigs

DEFF Research Database (Denmark)

Valtulini, S; Macchi, C; Ballanti, P

2005-01-01

The effect of intramuscular injection of 40 mg/2 ml aluminium hydroxide in the neck of pigs was examined in a number of ways. The investigation followed repeated slaughterhouse reports, according to which 64.8% of pigs from one particular farm were found at slaughter to have one or more nodules...... in the muscles of the neck (group slaughtered). The pigs had been injected with a vaccine containing 40 mg/2 ml dose of aluminium hydroxide as adjuvant. Research consisted of two phases: first, an epidemiological study was carried out, aimed at determining the risk factors for the granulomas. The results...... and adjuvant) to pigs inoculated twice with apyrogenic bi-distilled water (group water) and to pigs inoculated once with the adjuvant and once with apyrogenic bi-distilled water (group adjuvant/water). Both studies agreed in their conclusions, which indicate that the high amount of aluminium hydroxide...

Experiment on bio-leaching of associated molybdenum and uranium ore

International Nuclear Information System (INIS)

Zheng Ying; Fan Baotuan; Liu Jian; Meng Yunsheng; Liu Chao

2007-01-01

Column leaching experiment results on associated molybdenum uranium ore by bacteria (T. f) are introduced. The ore are leached for 210 days using bacteria domesticated to tolerate molybdenum, the leaching of uranium is of 98% and leaching of molybdenum is of 41%. Sulphuric acid produced by bio-oxidation of sulfides in ore can meet the demand of ore leaching. (authors)

Finite size melting of spherical solid-liquid aluminium interfaces

DEFF Research Database (Denmark)

Chang, J.; Johnson, Erik; Sakai, T.

2009-01-01

We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting tempera...... to the conclusion that the depressed melting temperature is not controlled solely by the inverse radius 1/R. Instead, we found a direct relation between the depressed melting temperature and the ratio between the solid-liquid interface area and the molten volume.......We have investigated the melting of nano-sized cone shaped aluminium needles coated with amorphous carbon using transmission electron microscopy. The interface between solid and liquid aluminium was found to have spherical topology. For needles with fixed apex angle, the depressed melting...

Structural perturbation of diphtheria toxoid upon adsorption to aluminium hydroxide adjuvant

NARCIS (Netherlands)

Regnier, M.; Metz, B.; Tilstra, W.; Hendriksen, C.; Jiskoot, W.; Norde, W.; Kersten, G.

2012-01-01

Aluminium-containing adjuvants are often used to enhance the potency of vaccines. In the present work we studied whether adsorption of diphtheria toxoid to colloidal aluminium hydroxide induces conformational changes of the antigen. Diphtheria toxoid has a high affinity for the aluminium hydroxide

NRC's limit on intake of uranium-ore dust

International Nuclear Information System (INIS)

McGuire, S.A.

1983-04-01

In 1960 the Atomic Energy Commission adopted an interim limit on the intake by inhalation of airborne uranium-ore dust. This report culminates two decades of research aimed at establishing the adequacy of that limit. The report concludes that the AEC underestimated the time that thorium-230, a constituent of uranium-ore dust, would remain in the human lung. The AEC assumed that thorium-230 in ore dust would behave like uranium with a 120-day biological half-life in the lung. This report concludes that the biological half-life is actually on the order of 1 year. Correcting the AEC's underestimate would cause a reduction in the permitted airborne concentration of uranium-ore dust. However, another factor that cancels the need for that reduction was found. The uranium ore dust in uranium mills was found to occur with very large particle sizes (10-micron activity median aerodynamic diameter). The particles are so large that relatively few of them are deposited in the pulmonary region of the lung, where they would be subject to long-term retention. Instead they are trapped in the upper regions of the respiratory tract, subsequently swallowed, and then rapidly excreted from the body through the gastrointestinal tract. The two effects are of about the same magnitude but in opposing directions. Thus the present uranium-ore dust intake limit in NRC regulations should provide a level of protection consistent with that provided for other airborne radioactive materials. The report recalculates the limit on intake of uranium-ore dust using the derived air concentrations (DAC) from the International Commission on Radiological Protection's recent Publication 30. The report concludes that the silica contained in uranium-ore dust is a greater hazard to workers than the radiological hazard

Disruption of an Alumina Layer During Sintering of Aluminium in Nitrogen

Directory of Open Access Journals (Sweden)

Pieczonka T.

2017-06-01

Full Text Available Aluminium oxide layer on aluminium particles cannot be avoided. However, to make the metal-metal contacts possible, this sintering barrier has to be overcome in some way, necessarily to form sintering necks and their development. It is postulated that the disruption of alumina layer under sintering conditions may originate physically and chemically. Additionally, to sinter successfully non alloyed aluminium powder in nitrogen, the operation of both types mechanism is required. It is to be noted that metallic aluminium surface has to be available to initiate reactions between aluminium and the sintering atmosphere, i.e. mechanical disruption of alumina film precedes the chemical reactions, and only then chemically induced mechanisms may develop. Dilatometry, gravimetric and differential thermal analyses, and microstructure investigations were used to study the sintering response of aluminium at 620°C in nitrogen, which is the only sintering atmosphere producing shrinkage.

Recycled Aluminium Cans/Eggshell Composites: Evaluation of Mechanical and Wear Resistance Properties

Directory of Open Access Journals (Sweden)

J.O. Agunsoye

2015-03-01

Full Text Available Aluminium based metal matrix composites have been produced from recycled aluminium cans and 150µm sized eggshell particles using a stir cast process. The mechanical properties of the control and aluminium can/eggshell composites produced have been investigated. The microstructures of the aluminium can/eggshell composites were examined with the aids of Scanning Electron Microscope (SEM after the sample surfaces have been carefully prepared and etched with aqueous solution of 0.5 cm3 nitric acid. Micrographs revealed that there was a homogenous distribution of eggshell particles within the aluminium can matrix. An indication of effective stirring action during the melting process. The wear resistance was also investigated under different applied loads (6 to 14 N on an abrasive surface emery paper of grade 220. The results revealed an increase in Young’s modulus of elasticity and yield stress from 1,206.45 and 50.23 Mpa respectively of the cast aluminium can with 0 % eggshell particle to the maximum of 3,258.87and 73.2 MPa of aluminium can/12 % eggshell composites. The hardness values increased from 66.23 to 75.13 VN. There was a gradual increase in wear rate of the tested samples as the applied load increased. However, the wear resistance of the aluminium can/6 % eggshell and aluminium can/12 % eggshell composites increased significantly. Hence, recycling of aluminium cans and eggshells can be harnessed into development of useful engineering metal matrix composite materials.

Collective sulphide flotation of the polymetallic molybdenic ore

International Nuclear Information System (INIS)

Mazanek, C.; Maselko, J.; Rycerz, L.

1980-01-01

Results of investigations on polymetallic molybdenic ore are presented. The useful minerals of this ore are as follows: molybdenite, sphalerite, galena and chalcopyrite whereas quartz, feldspars, chlorite and sericite are barren rocks. The flotation process parameters are established i.e. the consumption of flotation reagents, the flotation time and the most advantageous grain composition of the ore submitted to flotation. Taking into consideration the established parameters, a collective sulphide flotation of ore and a control flotation of wastes were carried out. The obtained concentrate was submitted to a single cleaning flotation whereby a concentrate was obtained containing: 4,65% Mo, 2,51% Cu, 0,9% Zn, 0,69% Pb, and 1,4% Bi. (author)

Origin of ores of endogeneous uranium ore deposits

International Nuclear Information System (INIS)

Kasanskij, V.I.; Laverov, N.P.; Tugarinov, A.I.

1976-01-01

The consideration mainly includes those endogenous uranium ore deposits of which more exact data are available, such as precambrian ones in areas of proto-activated old platforms, deposits of palaeozoic fold areas, and mesozoic deposits in areas of tectonic-magnetic activation. Their genesis and typical characters are mentioned and conclusions on the general distribution of the deposits are drawn. (author)

Surface roughness when diamond turning RSA 905 optical aluminium

Science.gov (United States)

Otieno, T.; Abou-El-Hossein, K.; Hsu, W. Y.; Cheng, Y. C.; Mkoko, Z.

2015-08-01

Ultra-high precision machining is used intensively in the photonics industry for the production of various optical components. Aluminium alloys have proven to be advantageous and are most commonly used over other materials to make various optical components. Recently, the increasing demand from optical systems for optical aluminium with consistent material properties has led to the development of newly modified grades of aluminium alloys produced by rapid solidification in the foundry process. These new aluminium grades are characterised by their finer microstructures and refined mechanical and physical properties. However the machining database of these new optical aluminium grades is limited and more research is still required to investigate their machinability performance when they are diamond turned in ultrahigh precision manufacturing environment. This work investigates the machinability of rapidly solidified aluminium RSA 905 by varying a number of diamond-turning cutting parameters and measuring the surface roughness over a cutting distance of 4 km. The machining parameters varied in this study were the cutting speed, feed rate and depth of cut. The results showed a common trend of decrease in surface roughness with increasing cutting distance. The lowest surface roughness Ra result obtained after 4 km in this study was 3.2 nm. This roughness values was achieved using a cutting speed of 1750 rpm, feed rate of 5 mm/min and depth of cut equal to 25 μm.

In vivo monitoring of skeletal aluminium burden in patients with renal failure

International Nuclear Information System (INIS)

Ellis, K.J.; Kelleher, S.; Raciti, A.; Savory, J.; Wills, M.

1988-01-01

In vivo neutron activation analysis was used to examine the total body and partial body (hand) aluminium levels in patients with end-stage renal failure. Patients maintained on chronic hemodialysis had higher mean body burdens of aluminium than did those clinically managed without dialysis. Approximately 70% of the patients examined indicated elevated levels of body or skeletal aluminium. A significant correlation was observed between the in vivo aluminium/calcium ratio obtained for the hand measurement and the increase in serum aluminium levels following a disferroxamine infusion test. The direct in vivo monitoring of hand Al/Ca values in patients may provide an alternate choice to bone biopsy for the detection of aluminium intoxication. (author) 15 refs.; 5 figs.; 2 tabs

Mining of sedimentary-type ore deposits

International Nuclear Information System (INIS)

Bruha, J.; Slovacek, T.; Berka, J.; Sadilek, P.

1992-01-01

A procedure is proposed for mining sedimentary-type ore deposits, particularly uranium deposits, using the stope-pillar technique. The stope having been mined out, the free room is filled with hydro-setting gob from the surface. A precondition for the application of this technique is horizontal ore mineralization in sediments where the total thickness of the mineralized ore layer is at least 3 to 5 m. Mining losses do not exceed 5%. For thicknesses greater than 5 m, the roof is reinforced and the walls are secured with netting. The assets of the technique include higher labor productivity of the driving, lower material demands in reinforcing and filling, lower power consumption, and reduced use of explosives. (Z.S.). 3 figs

Dietary exposure to aluminium in the popular Chinese fried bread youtiao.

Science.gov (United States)

Li, Ge; Zhao, Xue; Wu, Shimin; Hua, Hongying; Wang, Qiang; Zhang, Zhiheng

2017-06-01

Youtiao is a typical, traditional and widely consumed fried food in China. Fermentation of youtiao involves the use of aluminium potassium sulphate (alum). There are health concerns related to the levels of aluminium in food; therefore, we aimed to determine the aluminium concentrations of youtiao from various locations, and to estimate the dietary exposure by different age groups in southern and northern China. The aluminium content of youtiao samples varied considerably (range = 4.46-852.69 mg kg -1 ). Both the mean and median aluminium contents of youtiao exceeded 100 mg kg -1 , which is the China National Standard (GB) 2760-2014 National Food Safety for Standards for food additives. However, the median and 97.5th percentile of weekly dietary exposure to aluminium from youtiao, estimated using Monte Carlo simulation, did not exceed the provisional tolerable weekly intake (PTWI) set by the joint FAO/WHO Expert Committee on Food Additives (JECFA) for children, adolescents, adults and seniors. The weekly dietary exposure to aluminium would exceed the PTWI if children, adolescents, adults and seniors consumed 134.47, 260.98, 327.10 or 320.41 g of youtiao per week, respectively.

40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

Science.gov (United States)

2010-07-01

... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions of subpart D...

Silicon Alloying On Aluminium Based Alloy Surface

International Nuclear Information System (INIS)

Suryanto

2002-01-01

Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

Dietary exposure to aluminium of urban residents from cities in South China.

Science.gov (United States)

Jiang, Qi; Wang, Jing; Li, Min; Liang, Xuxia; Dai, Guangwei; Hu, Zhikun; Wen, Jian; Huang, Qiong; Zhang, Yonghui

2013-01-01

A dietary survey was conducted over three consecutive days by using 24-hour dietary recall in the Pearl River Delta of South China to investigate the dietary consumption status. A total of 1702 food samples, 22 food groups, were collected, and aluminium concentrations of foods were determined by using ICP-MS. Weekly dietary exposure to aluminium of the average urban residents of South China was estimated to be 1.5 mg kg⁻¹ body weight, which amounted to 76% of the provisional tolerable weekly intake. Wheat-made products (53.5%) contributed most to the dietary exposure, followed by vegetables (12.2%). The high-level consumers' weekly exposure to aluminium was 11.1 mg kg⁻¹ body weight, which amounted to 407% of the provisional tolerable weekly intake. The results indicated that the general urban residents in South China might be safe from aluminium exposure, but the high-level consumers might be at some risk of aluminium exposure. The foods contributing to aluminium exposure were processed food with aluminium-containing food additives. It is necessary to take effective measures to control the overuse of aluminium-containing food additives.

Usage of neural network to predict aluminium oxide layer thickness.

Science.gov (United States)

Michal, Peter; Vagaská, Alena; Gombár, Miroslav; Kmec, Ján; Spišák, Emil; Kučerka, Daniel

2015-01-01

This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage) and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A · dm(-2) and 3 A · dm(-2) for creating aluminium oxide layer.

Usage of Neural Network to Predict Aluminium Oxide Layer Thickness

Directory of Open Access Journals (Sweden)

Peter Michal

2015-01-01

Full Text Available This paper shows an influence of chemical composition of used electrolyte, such as amount of sulphuric acid in electrolyte, amount of aluminium cations in electrolyte and amount of oxalic acid in electrolyte, and operating parameters of process of anodic oxidation of aluminium such as the temperature of electrolyte, anodizing time, and voltage applied during anodizing process. The paper shows the influence of those parameters on the resulting thickness of aluminium oxide layer. The impact of these variables is shown by using central composite design of experiment for six factors (amount of sulphuric acid, amount of oxalic acid, amount of aluminium cations, electrolyte temperature, anodizing time, and applied voltage and by usage of the cubic neural unit with Levenberg-Marquardt algorithm during the results evaluation. The paper also deals with current densities of 1 A·dm−2 and 3 A·dm−2 for creating aluminium oxide layer.

Preface

International Nuclear Information System (INIS)

Mirsaidov, U.; Mamatov, E.D.; Safiev, Kh.S.

2013-01-01

This book presents the results of research works conducted in V.I. Nikitin Institute of Chemistry, Academy of Sciences of the Republic of Tajikistan and Nuclear and Radiation Safety Agency of the Academy of Sciences of the Republic of Tajikistan. Present book describes the specifics of chloric decomposition process of boron-silicate and aluminium containing ores of the Republic of Tajikistan. One of the main purpose of research is elaboration of methods of boron- and aluminium containing compounds obtaining from ores by chloric methods.

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

Energy Technology Data Exchange (ETDEWEB)

Mouturat, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete

The aluminium content of breast tissue taken from women with breast cancer.

Science.gov (United States)

House, Emily; Polwart, Anthony; Darbre, Philippa; Barr, Lester; Metaxas, George; Exley, Christopher

2013-10-01

The aetiology of breast cancer is multifactorial. While there are known genetic predispositions to the disease it is probable that environmental factors are also involved. Recent research has demonstrated a regionally specific distribution of aluminium in breast tissue mastectomies while other work has suggested mechanisms whereby breast tissue aluminium might contribute towards the aetiology of breast cancer. We have looked to develop microwave digestion combined with a new form of graphite furnace atomic absorption spectrometry as a precise, accurate and reproducible method for the measurement of aluminium in breast tissue biopsies. We have used this method to test the thesis that there is a regional distribution of aluminium across the breast in women with breast cancer. Microwave digestion of whole breast tissue samples resulted in clear homogenous digests perfectly suitable for the determination of aluminium by graphite furnace atomic absorption spectrometry. The instrument detection limit for the method was 0.48 μg/L. Method blanks were used to estimate background levels of contamination of 14.80 μg/L. The mean concentration of aluminium across all tissues was 0.39 μg Al/g tissue dry wt. There were no statistically significant regionally specific differences in the content of aluminium. We have developed a robust method for the precise and accurate measurement of aluminium in human breast tissue. There are very few such data currently available in the scientific literature and they will add substantially to our understanding of any putative role of aluminium in breast cancer. While we did not observe any statistically significant differences in aluminium content across the breast it has to be emphasised that herein we measured whole breast tissue and not defatted tissue where such a distribution was previously noted. We are very confident that the method developed herein could now be used to provide accurate and reproducible data on the aluminium content

Iron isotope fractionation during hydrothermal ore deposition and alteration

Science.gov (United States)

Markl, Gregor; von Blanckenburg, Friedhelm; Wagner, Thomas

2006-06-01

Iron isotopes fractionate during hydrothermal processes. Therefore, the Fe isotope composition of ore-forming minerals characterizes either iron sources or fluid histories. The former potentially serves to distinguish between sedimentary, magmatic or metamorphic iron sources, and the latter allows the reconstruction of precipitation and redox processes. These processes take place during ore formation or alteration. The aim of this contribution is to investigate the suitability of this new isotope method as a probe of ore-related processes. For this purpose 51 samples of iron ores and iron mineral separates from the Schwarzwald region, southwest Germany, were analyzed for their iron isotope composition using multicollector ICP-MS. Further, the ore-forming and ore-altering processes were quantitatively modeled using reaction path calculations. The Schwarzwald mining district hosts mineralizations that formed discontinuously over almost 300 Ma of hydrothermal activity. Primary hematite, siderite and sulfides formed from mixing of meteoric fluids with deeper crustal brines. Later, these minerals were partly dissolved and oxidized, and secondary hematite, goethite and iron arsenates were precipitated. Two types of alteration products formed: (1) primary and high-temperature secondary Fe minerals formed between 120 and 300 °C, and (2) low-temperature secondary Fe minerals formed under supergene conditions (illustrates the potential of the new technique in deciphering ore formation and alteration processes. Isotope ratios are strongly dependent on and highly characteristic of fluid and precipitation histories. Therefore, they are less suitable to provide information on Fe sources. However, it will be possible to unravel the physico-chemical processes leading to the formation, dissolution and redeposition of ores in great detail.

Uranium ore deposits: geology and processing implications

International Nuclear Information System (INIS)

Belyk, C.L.

2010-01-01

There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique set of geological characteristics which may also result in unique processing implications. Primary uranium production in the past decade has predominantly come from only a few of these deposit types including: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic ones. Processing implications can vary widely between and within the different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy, ore hardness, porosity, uranium mineral morphology and carbon content. Processing difficulties may occur as a result of one or more of these characteristics. In order to meet future uranium demand, it is imperative that innovative processing approaches and new technological advances be developed in order that many of the marginally economic traditional and uneconomic non-traditional uranium ore deposits can be exploited. (author)

Multi-Criteria selection of technology for processing ore raw materials

Science.gov (United States)

Gorbatova, E. A.; Emelianenko, E. A.; Zaretckii, M. V.

2017-10-01

The development of Computer-Aided Process Planning (CAPP) for the Ore Beneficiation process is considered. The set of parameters to define the quality of the Ore Beneficiation process is identified. The ontological model of CAPP for the Ore Beneficiation process is described. The hybrid choice method of the most appropriate variant of the Ore Beneficiation process based on the Logical Conclusion Rules and the Fuzzy Multi-Criteria Decision Making (MCDM) approach is proposed.

Separation of monazite from Rirang ore by floatation method

International Nuclear Information System (INIS)

Affandi, Kosim; Sjahminan, Mainar

1995-01-01

Separation of monazite from Rirang ore has been carried out by means of floatation using oleic acid and pine oil as promoter and frothier reagents, respectively. Several parameters affecting floatation process, i.e. grain size of the ore, pulp pH, and reagents concentration were examnined. The optimal conditions for the process include the use of -100 mesh feed ore, pulp pH 9.0 and 1 kilogram of each oleic acid and pine oil per tonne ore. Based on the conditions, monazite recovery of 90% was achieved with about 20% uranium remain in monazite concentrate. (author). 7 refs, 9tabs, 1 fig

O-Ring sealing arrangements for ultra-high vacuum systems

Science.gov (United States)

Kim, Chang-Kyo; Flaherty, Robert

1981-01-01

An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

Potentiometric titration curves of aluminium salt solutions and its ...

African Journals Online (AJOL)

Potentiometric titration curves of aluminium salt solutions and its species conversion ... of aluminium salt solutions under the moderate slow rate of base injection. ... silicate radical, and organic acid radical on the titration curves and its critical ...

Bioaccumulation of Aluminium in Hydromacrophytes in Polish Coastal Lakes

Directory of Open Access Journals (Sweden)

Senze Magdalena

2015-03-01

Full Text Available The research on aluminium content was conducted in water and on aquatic flora of Polish lakes in the central part of the coast. The study included the lakes Sarbsko, Choczewskie, Bia.e, K.odno, D.brze and Salino investigated in the summer of 2013. The examined lakes belong mainly to the direct basin of the Baltic Sea. Samples of aquatic plants and lake waters were collected. In the water samples pH and electrolytic conductivity were measured. The aluminium content was determined both in water and aquatic plants. Submerged hydromacrophyte studies included Myriophyllum alterniflorum L., Potamogeton perfoliatus L. and Ceratophyllum demersum L. Emergent hydromacrophyte studies included Phragmites australis (Cav. Trin. ex Steud., Juncus bulbosus L., Iris pseudacorus L., Eleocharis palustris (L. Roem. % Schult., Phalaris arundinacea L., Carex riparia Curt., Mentha aquatic L., Stratiotes aloides L., Alisma plantago-aquatica L., Glyceria maxima (Hartman Holmb., Sagittaria sagittifolia L., Scirpus lacustris L. and Typha angustifolia L. The purpose of this investigation was the determination of the aluminium content in submerged and emergent hydromacrophytes and also the definition of their bioaccumulative abilities. The average concentration of aluminium in water was 2.68 fęg Al dm.3. The average content of aluminium in plants was 2.8015 mg Al kg.1. The bioaccumulation factor ranged from BCF=19.74 to BCF=16619. On the basis of the analysis of the aluminium content in water and aquatic plants results show that both water and plants were characterized by a moderate level of aluminium. The recorded concentrations indicate a mid-range value and are much lower than those which are quoted for a variety of surface waters in various parts of the world.

Lake restoration with aluminium, bentonite and Phoslock: the effect on sediment stability and light attenuation

DEFF Research Database (Denmark)

Egemose, Sara; Reitzel, Kasper; Flindt, Mogens

treatments on aluminium mobility, sediment stability or light climate. A laboratory flume experiment including three shallow Danish lakes was conducted. We measured the effects of aluminium, Phoslock (a commercial product), bentonite, and a combination of bentonite/aluminium. Each treatment caused a varying...... consolidation of the sediment. The largest consolidation occurred using Phoslock- and bentonite-addition followed by bentonite/aluminium-addition, whereas aluminium alone had no effect. Sediment stability thresholds were measured before and after addition. Especially Phoslock, but also bentonite and bentonite....../aluminium increased sediment erosion threshold, with respectively 200%, 43% and 57%. Aluminium, bentonite/aluminium, and Phoslock improved the light conditions in the water phase, with respectively 60%, 57% and 50%, whereas bentonite created higher turbidity. Conclusively aluminium improved the light conditions...

Anodization of Aluminium using a fast two-step process

Indian Academy of Sciences (India)

283.6 eV. Keywords. Anodization; phosphoric acid; anodization time; anodized aluminium oxide; aluminium. ... of anodization.5–7 The AAO layer has a large band gap, good ..... transmittance increases as the anodised membrane is heated to ...

Serum aluminium levels in glue-sniffer adolescent and in glue containers.

Science.gov (United States)

Akay, Cemal; Kalman, Süleyman; Dündaröz, Ruşen; Sayal, Ahmet; Aydin, Ahmet; Ozkan, Yalçin; Gül, Hüsamettin

2008-05-01

Glue sniffing is a serious medical problem among teenagers. Various chemical substances such as toluene and benzene containing glues have been reported to be toxic. It has been demonstrated that some toxic metals such as lead are elevated in the blood of solvent-addicted patients. Whereas aluminium is an element that has toxic effects on neurological, hematopoetic system and bone metabolism. We want to determine the serum levels of aluminium in glue-sniffer adolescents in comparison with healthy subjects. In addition, we compared aluminium levels of different commercial glue preparations (i.e. metal and plastic containers), to determine which type of container is better for less aluminium toxicity. We measured serum levels of aluminium in 37 glue-sniffer and 37 healthy subjects using atomic absorption spectrophotometry. The average duration of glue-sniffer was 3.8 +/- 0.8 years. We also measured aluminium levels of 10 commercial glue preparations that seven of them with metal and three with plastic containers. We found that serum levels of aluminium were 63.29 +/- 13.20 ng/ml and 36.7 +/- 8.60 ng/ml in glue-sniffer and in control subjects, respectively (P sniffers, it may be a good step to market of glue preparations in plastic instead of metal containers.

Derivation of a water quality guideline for aluminium in marine waters.

Science.gov (United States)

Golding, Lisa A; Angel, Brad M; Batley, Graeme E; Apte, Simon C; Krassoi, Rick; Doyle, Chris J

2015-01-01

Metal risk assessment of industrialized harbors and coastal marine waters requires the application of robust water quality guidelines to determine the likelihood of biological impacts. Currently there is no such guideline available for aluminium in marine waters. A water quality guideline of 24 µg total Al/L has been developed for aluminium in marine waters based on chronic 10% inhibition or effect concentrations (IC10 or EC10) and no-observed-effect concentrations (NOECs) from 11 species (2 literature values and 9 species tested including temperate and tropical species) representing 6 taxonomic groups. The 3 most sensitive species tested were a diatom Ceratoneis closterium (formerly Nitzschia closterium; IC10 = 18 µg Al/L, 72-h growth rate inhibition) aluminium forms of aluminate (Al(OH4 (-) ) and aluminium hydroxide (Al(OH)3 (0) ) although both dissolved, and particulate aluminium contributed to toxicity in the diatom Minutocellus polymorphus and green alga Dunaliella tertiolecta. In contrast, aluminium toxicity to the green flagellate alga Tetraselmis sp. was the result of particulate aluminium only. Four species, a brown macroalga (Hormosira banksii), sea urchin embryo (Heliocidaris tuberculata), and 2 juvenile fish species (Lates calcarifer and Acanthochromis polyacanthus), were not adversely affected at the highest test concentration used. © 2014 SETAC.

Automated microscopic characterization of metallic ores with image analysis: a key to improve ore processing. II: metallogenetic discriminating criteria

International Nuclear Information System (INIS)

Castroviejo, R.; Berrezueta, E.

2009-01-01

ore microscopy may furnish very important information for geo metallurgists, but todays needs for automation are difficult to meet with the optical microscope unless and adequate methodology is developed. Some limitations of the routine procedure, related to risks of mis identification caused by the spectral similarity of some ores, ask for complementary criteria. Defining ore deposit typologies and the corresponding assemblages guides the choice of species and limits the number. Comparison of the reflectance values of the ores in each mineral association defined shows that their automated identification is possible in most of the common occurrence. The number of species to be actually considered being greatly limited, performance is increased. The system is not intended to substitute for a mineralogist, but to enhance enormously his performance, while offering the industry an economic procedure to procedure a wealth of information which would not be possible with traditional methods, as the point counter. (Author) 33 refs.

Cancer risk among workers of a secondary aluminium smelter.

Science.gov (United States)

Maltseva, A; Serra, C; Kogevinas, M

2016-07-01

Cancer risk in secondary aluminium production is not well described. Workers in this industry are exposed to potentially carcinogenic agents from secondary smelters that reprocess aluminium scrap. To evaluate cancer risk in workers in a secondary aluminium plant in Spain. Retrospective cohort study of male workers employed at an aluminium secondary smelter (1960-92). Exposure histories and vital status through 2011 were obtained through personal interviews and hospital records, respectively. Standardized mortality (SMRs) and incidence ratios (SIRs) were calculated. The study group consisted of 98 workers. We found increased incidence and mortality from bladder cancer [SIR = 2.85, 95% confidence interval (CI) 1.23-5.62; SMR = 5.90, 95% CI 1.58-15.11]. Increased incidence was also observed for prostate cancer and all other cancers but neither were statistically significant. No increased risk was observed for lung cancer. Results of this study suggest that work at secondary aluminium smelters is associated with bladder cancer risk. Identification of occupational carcinogens in this industry is needed. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Deposition of aluminium nanoparticles using dense plasma focus device

International Nuclear Information System (INIS)

Devi, Naorem Bilasini; Srivastava, M P; Roy, Savita

2010-01-01

Plasma route to nanofabrication has drawn much attention recently. The dense plasma focus (DPF) device is used for depositing aluminium nanoparticles on n-type Si (111) wafer. The plasma chamber is filled with argon gas and evacuated at a pressure of 80 Pa. The substrate is placed at distances 4.0 cm, 5.0 cm and 6.0 cm from the top of the central anode. The aluminium is deposited on Si wafer at room temperature with two focused DPF shots. The deposits on the substrate are examined for their morphological properties using atomic force microscopy (AFM). The AFM images have shown the formation of aluminium nanoparticles. From the AFM images, it is found that the size of aluminium nanoparticles increases with increase in distance between the top of anode and the substrate for same number of DPF shots.

The geological characteristics and forming conditions of granite type uranium-rich ore deposits

Energy Technology Data Exchange (ETDEWEB)

Tiangang, Li; Hangshou, Tong; Mingyue, Feng; Yuexiang, Li; Zhan, Xu [Beijing Research Inst. of Uranium Geology (China)

1993-03-01

The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage.

The geological characteristics and forming conditions of granite type uranium-rich ore deposits

International Nuclear Information System (INIS)

Li Tiangang; Tong Hangshou; Feng Mingyue; Li Yuexiang; Xu Zhan

1993-03-01

The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage

Corrosion issues of powder coated AA6060 aluminium profiles

DEFF Research Database (Denmark)

Din, Rameez Ud; Valgarðsson, Smári; Jellesen, Morten Stendahl

2015-01-01

In this study detailed microstructural investigation of the reason for unexpected corrosion of powder coated aluminium alloy AA6060 windows profiles has been performed. The results from this study reveals that the failure of the window profiles was originated from the surface defects present...... on the extruded AA6060 aluminium profile after metallurgical process prior to powder coating. Surface defects are produced due to intermetallic particles in the alloy, which disturb the flow during the extrusion process. The corrosion mechanism leading to the failure of the powder coated AA6060 aluminium profiles...

Uranium extraction from gold-uranium ores

Energy Technology Data Exchange (ETDEWEB)

Laskorin, B.N.; Golynko, Z.Sh.

1981-01-01

The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.

Aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference.

Science.gov (United States)

Zhao, Xue Qiang; Guo, Shi Wei; Shinmachi, Fumie; Sunairi, Michio; Noguchi, Akira; Hasegawa, Isao; Shen, Ren Fang

2013-01-01

Acidic soils are dominated chemically by more ammonium and more available, so more potentially toxic, aluminium compared with neutral to calcareous soils, which are characterized by more nitrate and less available, so less toxic, aluminium. However, it is not known whether aluminium tolerance and nitrogen source preference are linked in plants. This question was investigated by comparing the responses of 30 rice (Oryza sativa) varieties (15 subsp. japonica cultivars and 15 subsp. indica cultivars) to aluminium, various ammonium/nitrate ratios and their combinations under acidic solution conditions. indica rice plants were generally found to be aluminium-sensitive and nitrate-preferring, while japonica cultivars were aluminium-tolerant and relatively ammonium-preferring. Aluminium tolerance of different rice varieties was significantly negatively correlated with their nitrate preference. Furthermore, aluminium enhanced ammonium-fed rice growth but inhibited nitrate-fed rice growth. The results suggest that aluminium tolerance in rice is antagonistic with nitrate preference and synergistic with ammonium preference under acidic solution conditions. A schematic diagram summarizing the interactions of aluminium and nitrogen in soil-plant ecosystems is presented and provides a new basis for the integrated management of acidic soils.

An outlook into energy consumption in large scale industries in India: The cases of steel, aluminium and cement

International Nuclear Information System (INIS)

Dutta, Monica; Mukherjee, Saptarshi

2010-01-01

All the growth-oriented sectors in a developing economy consume enormous energy in their production processes. Steel, aluminium and cement are the key manufacturing industries in India which provide inputs to various other sectors such as construction, transportation, power transmission, etc. As a result, their demand is consistently rising. These industries are heavily energy-intensive and use raw materials such as iron ore, coal, electricity, steam, and fuel oil, whose supply can act as severe production constraints over a period of time and can hinder sustainable development. Hence it becomes imperative for these industries to continuously innovate more energy efficient techniques. This paper makes a foray into the energy demand for these industries and explores the potential of any future reduction in their energy consumption. The paper offers a projection scenario for 2001-2031 (based on the MARKAL Modeling exercise for India) for possible catching up in reduction in energy consumptions in these sectors under alternative situations. The analysis suggests the existence of some plausible energy efficiency enhancing techniques in these industries. Exploring these options will definitely ensure cost effectiveness and competitiveness of these three key sectors in the global market. -- Research highlights: →Energy reduction potential exists in Indian steel, aluminium and cement sectors and can go up to 8%, 17% and 6% respectively in these sectors in 2031 if appropriate energy saving technologies are introduced and implemented. →In aluminium industry energy reduction potential is huge in fabrication stage in the production process and extensive improvement can be done in terms of energy efficiency in this stage. Cogeneration of power through waste heat recovery, change in norms in standard to take advantage of producing composite cements using more than one industrial waste, like both fly ash and slag are important required changes in Indian cement sector. �

Synthesis, properties, and assimilation methods of aluminium hydride

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2013-01-01

We have discovered a new source of aluminium hydride-conversion of tetrahydrofurane under influence of halogenous alkyls. We have proposed the chlorbenzene method of synthesis of AlH 3 , which excludes adhesion and ensure high quality of the product with respect to its purity, thermal stability, habits of crystals (round shape), and granulometric composition. We determined capability of benzyl chloride to fix AlH 4 -groups by the way of complexes formation. This allows increasing efficient concentration of AlH 3 solutions and their productivity. We have carried out 'direct' crystallization of aluminium hydride in one stage using interaction of binary metal hydride with aluminium chloride in the medium of ether-toluene at 60-100 d ig C a nd using solvent distillation. In the reaction of Li H with AlCl 3 , we achieved output of pure crystal AlH 3 of hexagonal modification, which was close to quantitative. We have discovered the assimilation methods of aluminium hydride in carrying out of solid-phase chemical reactions. (author)

Breakaway frictions of dynamic O-rings in mechanical seals

Science.gov (United States)

Lai, Tom; Kay, Peter

1993-05-01

Breakaway friction of a dynamic O-ring affects the mechanical seal's response to large axial shaft movement and face wear. However, little data exist to help designers. Therefore, a test rig was developed to measure breakaway friction. The research quantitatively shows the effects of lubrication with silicone grease and a change of surface finish. By using the Taguchi statistical experimental design method, the significance of test parameters was evaluated with a minimum number of tests. It was found that fluid pressure, dwell time, and O-ring percentage squeeze affect O-ring breakaway friction more than the O-ring cross sectional diameter and axial sliding speed within the range of values tested. The authors showed that breakaway friction increased linearly with pressure. However, O-rings made of different materials had significantly different increase rates, even if they had nominally the same durometer hardness. Breakaway friction also increased with logarithm of dwell time. Again, the increase rate depended strongly on the specific O-ring material tested. These observations led the authors to believe that the typical approach of generalizing data based on generic polymer type and durometer was inappropriate.

Indentation of aluminium foam at low velocity

Directory of Open Access Journals (Sweden)

Shi Xiaopeng

2015-01-01

Full Text Available The indentation behaviour of aluminium foams at low velocity (10 m/s ∼ 30 m/s was investigated both in experiments and numerical simulation in this paper. A flat-ended indenter was used and the force-displacement history was recorded. The Split Hopkinson Pressure bar was used to obtain the indentation velocity and forces in the dynamic experiments. Because of the low strength of the aluminium foam, PMMA bar was used, and the experimental data were corrected using Bacon's method. The energy absorption characteristics varying with impact velocity were then obtained. It was found that the energy absorption ability of aluminium foam gradually increases in the quasi-static regime and shows a significant increase at ∼10 m/s velocity. Numerical simulation was also conducted to investigate this process. A 3D Voronoi model was used and models with different relative densities were investigated as well as those with different failure strain. The indentation energy increases with both the relative density and failure strain. The analysis of the FE model implies that the significant change in energy absorption ability of aluminium foam in indentation at ∼10 m/s velocity may be caused by plastic wave effect.

Improvement of photodynamic activity of aluminium sulphophthalocyanine due to biotinylation

Science.gov (United States)

Meerovich, Irina G.; Jerdeva, Victoria V.; Derkacheva, Valentina M.; Meerovich, Gennadii A.; Lukyanets, Eugeny A.; Kogan, Eugenia A.; Savitsky, Alexander P.

2003-09-01

The photodynamic activity of dibiotinylated aluminium sulphophthalocyanine in vitro and in vivo were studied. It was obtained that in vitro dibiotinylated aluminium sulphophthalocyanine provides the effective damage of small cell lung carcinoma OAT-75. In vivo dibiotinylated aluminium sulphophthalocyanine causes destruction of tumor (Erlich carcinoma), results in total necrosis of tumor tissue and expresses vascular damage (trombosis and destruction of vascular walls) even in concentration 0.25 mg/kg of a body weight.

Flocculation of chromite ore fines suspension using polysaccharide ...

Indian Academy of Sciences (India)

Unknown

liquid separation. Keywords. Flocculation; graft copolymer; mineral industry effluent; chromite ore fines; ... work well as flocculating agent on coal washery effluent, copper and iron ore fines etc (Karmakar et al 1998, 1999;. Tripathy et al 2001).

A study of the distribution of rare-metals in kuroko-type ore

International Nuclear Information System (INIS)

Murao, S.; Sie, S.H.; Suter, G.F.

1996-01-01

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab

A study of the distribution of rare-metals in kuroko-type ore

Energy Technology Data Exchange (ETDEWEB)

Murao, S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience]|[Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1996-12-31

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

A study of the distribution of rare-metals in kuroko-type ore

Energy Technology Data Exchange (ETDEWEB)

Murao, S [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1997-12-31

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

Aluminium supplier selection for the automotive parts manufacturer

Directory of Open Access Journals (Sweden)

M. Cieśla

2016-04-01

Full Text Available This paper presents a methodology for selection of the optimal sources of supply, which is also known as the problem of supplier selection. Theoretical considerations are expanded with research related to aluminium supplier selection for a hypothetical manufacturer of aluminium parts for transportation equipment located in Poland. Evaluation of five suppliers of aluminium from Poland, Germany and Slovenia has been conducted using a weighted scoring method, a strengths and weaknesses method and a graphical method. Choosing the best offer and prioritizing suppliers allows not only the most rational decision in the field of supply logistics to be taken but also the quality of service in the metallurgical industry to be improved.

Fundamentals of fast reduction of ultrafine iron ore at low temperature

Institute of Scientific and Technical Information of China (English)

Pei Zhao; Peimin Guo

2008-01-01

Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

1998-01-01

Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

Automated microscopic characterization of metallic ores with image analysis: a key to improve ore processing. I: test of the methodology

International Nuclear Information System (INIS)

Berrezueta, E.; Castroviejo, R.

2007-01-01

Ore microscopy has traditionally been an important support to control ore processing, but the volume of present day processes is beyond the reach of human operators. Automation is therefore compulsory, but its development through digital image analysis, DIA, is limited by various problems, such as the similarity in reflectance values of some important ores, their anisotropism, and the performance of instruments and methods. The results presented show that automated identification and quantification by DIA are possible through multiband (RGB) determinations with a research 3CCD video camera on reflected light microscope. These results were obtained by systematic measurement of selected ores accounting for most of the industrial applications. Polarized light is avoided, so the effects of anisotropism can be neglected. Quality control at various stages and statistical analysis are important, as is the application of complementary criteria (e.g. metallogenetic). The sequential methodology is described and shown through practical examples. (Author)

Do aluminium-based phosphate binders continue to have a role in contemporary nephrology practice?

Science.gov (United States)

Mudge, David W; Johnson, David W; Hawley, Carmel M; Campbell, Scott B; Isbel, Nicole M; van Eps, Carolyn L; Petrie, James J B

2011-05-13

Aluminium-containing phosphate binders have long been used for treatment of hyperphosphatemia in dialysis patients. Their safety became controversial in the early 1980's after reports of aluminium related neurological and bone disease began to appear. Available historical evidence however, suggests that neurological toxicity may have primarily been caused by excessive exposure to aluminium in dialysis fluid, rather than aluminium-containing oral phosphate binders. Limited evidence suggests that aluminium bone disease may also be on the decline in the era of aluminium removal from dialysis fluid, even with continued use of aluminium binders. The K/DOQI and KDIGO guidelines both suggest avoiding aluminium-containing binders. These guidelines will tend to promote the use of the newer, more expensive binders (lanthanum, sevelamer), which have limited evidence for benefit and, like aluminium, limited long-term safety data. Treating hyperphosphatemia in dialysis patients continues to represent a major challenge, and there is a large body of evidence linking serum phosphate concentrations with mortality. Most nephrologists agree that phosphate binders have the potential to meaningfully reduce mortality in dialysis patients. Aluminium is one of the cheapest, most effective and well tolerated of the class, however there are no prospective or randomised trials examining the efficacy and safety of aluminium as a binder. Aluminium continues to be used as a binder in Australia as well as some other countries, despite concern about the potential for toxicity. There are some data from selected case series that aluminium bone disease may be declining in the era of reduced aluminium content in dialysis fluid, due to rigorous water testing. This paper seeks to revisit the contemporary evidence for the safety record of aluminium-containing binders in dialysis patients. It puts their use into the context of the newer, more expensive binders and increasing concerns about the risks of

Do aluminium-based phosphate binders continue to have a role in contemporary nephrology practice?

Directory of Open Access Journals (Sweden)

van Eps Carolyn L

2011-05-01

Full Text Available Abstract Background Aluminium-containing phosphate binders have long been used for treatment of hyperphosphatemia in dialysis patients. Their safety became controversial in the early 1980's after reports of aluminium related neurological and bone disease began to appear. Available historical evidence however, suggests that neurological toxicity may have primarily been caused by excessive exposure to aluminium in dialysis fluid, rather than aluminium-containing oral phosphate binders. Limited evidence suggests that aluminium bone disease may also be on the decline in the era of aluminium removal from dialysis fluid, even with continued use of aluminium binders. Discussion The K/DOQI and KDIGO guidelines both suggest avoiding aluminium-containing binders. These guidelines will tend to promote the use of the newer, more expensive binders (lanthanum, sevelamer, which have limited evidence for benefit and, like aluminium, limited long-term safety data. Treating hyperphosphatemia in dialysis patients continues to represent a major challenge, and there is a large body of evidence linking serum phosphate concentrations with mortality. Most nephrologists agree that phosphate binders have the potential to meaningfully reduce mortality in dialysis patients. Aluminium is one of the cheapest, most effective and well tolerated of the class, however there are no prospective or randomised trials examining the efficacy and safety of aluminium as a binder. Aluminium continues to be used as a binder in Australia as well as some other countries, despite concern about the potential for toxicity. There are some data from selected case series that aluminium bone disease may be declining in the era of reduced aluminium content in dialysis fluid, due to rigorous water testing. Summary This paper seeks to revisit the contemporary evidence for the safety record of aluminium-containing binders in dialysis patients. It puts their use into the context of the newer, more

Do aluminium-based phosphate binders continue to have a role in contemporary nephrology practice?

Science.gov (United States)

2011-01-01

Background Aluminium-containing phosphate binders have long been used for treatment of hyperphosphatemia in dialysis patients. Their safety became controversial in the early 1980's after reports of aluminium related neurological and bone disease began to appear. Available historical evidence however, suggests that neurological toxicity may have primarily been caused by excessive exposure to aluminium in dialysis fluid, rather than aluminium-containing oral phosphate binders. Limited evidence suggests that aluminium bone disease may also be on the decline in the era of aluminium removal from dialysis fluid, even with continued use of aluminium binders. Discussion The K/DOQI and KDIGO guidelines both suggest avoiding aluminium-containing binders. These guidelines will tend to promote the use of the newer, more expensive binders (lanthanum, sevelamer), which have limited evidence for benefit and, like aluminium, limited long-term safety data. Treating hyperphosphatemia in dialysis patients continues to represent a major challenge, and there is a large body of evidence linking serum phosphate concentrations with mortality. Most nephrologists agree that phosphate binders have the potential to meaningfully reduce mortality in dialysis patients. Aluminium is one of the cheapest, most effective and well tolerated of the class, however there are no prospective or randomised trials examining the efficacy and safety of aluminium as a binder. Aluminium continues to be used as a binder in Australia as well as some other countries, despite concern about the potential for toxicity. There are some data from selected case series that aluminium bone disease may be declining in the era of reduced aluminium content in dialysis fluid, due to rigorous water testing. Summary This paper seeks to revisit the contemporary evidence for the safety record of aluminium-containing binders in dialysis patients. It puts their use into the context of the newer, more expensive binders and increasing

An interesting and efficient green corrosion inhibitor for aluminium ...

African Journals Online (AJOL)

An interesting and efficient green corrosion inhibitor for aluminium from extracts of ... Journal Home > Vol 13, No 1 (2014) > ... possible applications in metal surface anodizing and surface coating in industries. Keywords: Moringa oleifera, Aluminium, Hydrochloric acid, Langmuir isotherm, Plant extracts, Corrosion inhibition ...

Uranium accompanying recovery from copper ores

International Nuclear Information System (INIS)

Golynko, Z.Sh.; Laskorin, B.N.

1981-01-01

In the search for new raw material sources for nuclear power engineering a review of the technique of uranium accompaning recovery from copper ores reprocessing products in some countries is presented. In the USA a sorption method of uranium extraction by means of strongly basic ion exchange resins from solutions upon copper case- hardening with subsequent extraction from eluates by solutions of tertiary amines is realized. Elution is realized with sulphuric acid. In South Africa an extraction reprocessing of gravitational concentrate extracted from copper sulphide flotation tailings is organized. In India the uranium extraction from copper ores flotation enrichment tailings is organized on a commerical scale. Presented are data on the scale of uranium recovery, various conditions of its recovery as well as block diagrams of the processes. It is shown that copper ores become an additional source of uranium recovery [ru

Research on degradation of vacuum O-rings under gamma radiation

CERN Document Server

Ino, H; Saitô, Y; Kubo, T; Kinsho, M

2003-01-01

The high-intensity proton accelerator being constructed by JAERI and KEK will generates greater beam power than conventional accelerators. The radiation emission due to beam losses will therefore increase. Since vacuum O-rings installed in the accelerator will be degraded badly by the radiation, there is need to find an O-ring that has more resistant to radiation. To find an O-ring that has better radiation resistant than that of the fluororubber used for conventional accelerators in general, some O-rings which are expected to have enough resistant to the radiation were irradiated, and estimated a degradation by measurement of outgassing rate, hardness, permeation time of helium gas, and an outward observation. Most of the O-rings were irradiated in an oxygen free atmosphere and in the air. The irradiations were carried out at room temperature in Co-60 gamma irradiation facility until a dose of 1 MGy was reached. The radiation resistance of PURE-RUBBER O-ring showed somewhat better than that of the fluororubb...

Power distribution: conductors in aluminium

International Nuclear Information System (INIS)

Schmid, R.

2007-01-01

This article takes a look at the use of aluminium conductors in medium and low-voltage cables. The author discusses how the increasing price of copper has led to the increasing use of aluminium as a material for the production of the conductors used in medium and low-voltage power cables. Aid is provided that is to help purchasers make the correct decisions when buying medium and low-voltage cables. The current market situation is examined and the appropriate norms are looked at. Technical data and economic aspects are discussed, both for medium and low-voltage applications. The electrical characteristics of the type of cable to be used are examined and discussed

Spectrographic determination of trace impurities in reactor grade aluminium

International Nuclear Information System (INIS)

Chandola, L.C.; Machado, I.J.

1975-01-01

A spectrographic method enabling the determination of 21 trace impurities in aluminium oxide is described. The technique involves mixing the sample with graphite buffer in the ratio 1:1, loading it in a graphite electrode and arcing it for 30 sec. in a dc arc to 10 A current against a pointed graphite cathode. The spectra are photographed on Ilford N.30 emulsion employing a large quartz spectrograph. The aluminium line at 2669.2 A 0 serves as the internal standard. The impurities determined are Ag, B, Bi, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mo, Ni, Pb, Sb, Si, Sn, Ti, V and Zn. The sensitivity varies from 5 to 100 ppm and the precision from +- 5 to +- 22% for different elements. A method for converting aluminium metal to aluminium oxide is described. It is found that boron is not lost during this conversion. (author)

Friction and corrosion resistance of sputter deposited supersaturated metastable aluminium-molybdenum alloys

Energy Technology Data Exchange (ETDEWEB)

Abu-Zeid, O.A. [Univ. of the United Arab Emirates, Al-Ain (United Arab Emirates). Dept. of Mech. Eng.; Bates, R.I. [Design, Mfg. and Marketing Research Inst., Univ. of Salford (United Kingdom)

1996-12-15

Two closed field unbalanced magnetrons with targets of aluminium and molybdenum have been used for the co-deposition of aluminium-molybdenum coatings with different compositions. A pin on disk machine and a computer controlled potentiostat have been used to evaluate respectively, the tribological and corrosion properties of the deposited alloys. Results have shown that introducing molybdenum into aluminium coatings improves their poor tribological properties. Aluminium-molybdenum coatings with different compositions have shown low wear behaviour and for coatings with high molybdenum contents (> 80%) friction coefficients against steel, as low as 0.18 have been obtained. The addition of molybdenum into aluminium coatings has reduced their corrosion tendency and corrosion current density in a marine environment. (orig.)

Manual on laboratory testing for uranium ore processing

International Nuclear Information System (INIS)

1990-01-01

Laboratory testing of uranium ores is an essential step in the economic evaluation of uranium occurrences and in the development of a project for the production of uranium concentrates. Although these tests represent only a small proportion of the total cost of a project, their proper planning, execution and interpretation are of crucial importance. The main purposes of this manual are to discuss the objectives of metallurgical laboratory ore testing, to show the specific role of these tests in the development of a project, and to provide practical instructions for performing the tests and for interpreting their results. Guidelines on the design of a metallurgical laboratory, on the equipment required to perform the tests and on laboratory safety are also given. This manual is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Management. A report on the Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores (Technical Reports Series No. 196, 1980) and an instruction manual on Methods for the Estimation of Uranium Ore Reserves (No. 255, 1985) have already been published. 17 refs, 40 figs, 17 tabs

Uranium abundance in some sudanese phosphate ores

International Nuclear Information System (INIS)

Adam, A.A.; Eltayeb, M.A.H.

2009-01-01

This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

Natural resources sustainability: iron ore mining

International Nuclear Information System (INIS)

De La Torre de Palacios, Luis

2011-01-01

In the present article, a new tool to determine environmental sustainability, the energy impact index (EII) was developed to classify different iron mine projects according to two main parameters including energy consumption and CO 2 emissions. The EII considers the characteristics of the mineral (such as the quality, size, hardness, iron ore grade, reducibility, mineral/waste rate, and type of deposit), mining processes (type of exploitation, ore processing, available technology), and transportation (distance to cover).

Determination of gold in gold ores

International Nuclear Information System (INIS)

Keedy, C.R.; Parson, L.; Shen, J.

1989-01-01

The gold content of placer gold flakes and gold bearing ores was determined by instrumental and radiochemical neutron activation analysis, respectively. It was discovered that significant errors result in the instrumental method for gold flakes as small as 10 mg due to sample self-absorption of neutrons during irradiation. Reliable results were obtained for both ore samples and gold flakes by dissolving the samples in aqua regia prior to irradiation. (author) 7 refs.; 3 tabs

Towards toxicokinetic modelling of aluminium exposure from adjuvants in medicinal products.

Science.gov (United States)

Weisser, Karin; Stübler, Sabine; Matheis, Walter; Huisinga, Wilhelm

2017-08-01

As a potentially toxic agent on nervous system and bone, the safety of aluminium exposure from adjuvants in vaccines and subcutaneous immune therapy (SCIT) products has to be continuously re-evaluated, especially regarding concomitant administrations. For this purpose, knowledge on absorption and disposition of aluminium in plasma and tissues is essential. Pharmacokinetic data after vaccination in humans, however, are not available, and for methodological and ethical reasons difficult to obtain. To overcome these limitations, we discuss the possibility of an in vitro-in silico approach combining a toxicokinetic model for aluminium disposition with biorelevant kinetic absorption parameters from adjuvants. We critically review available kinetic aluminium-26 data for model building and, on the basis of a reparameterized toxicokinetic model (Nolte et al., 2001), we identify main modelling gaps. The potential of in vitro dissolution experiments for the prediction of intramuscular absorption kinetics of aluminium after vaccination is explored. It becomes apparent that there is need for detailed in vitro dissolution and in vivo absorption data to establish an in vitro-in vivo correlation (IVIVC) for aluminium adjuvants. We conclude that a combination of new experimental data and further refinement of the Nolte model has the potential to fill a gap in aluminium risk assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

RESPONSE OF PHENOLIC METABOLISM INDUCED BY ALUMINIUM TOXICITY IN FAGOPYRUM ESCULENTUM MOENCH. PLANTS.

Science.gov (United States)

Smirnov, O E; Kosyan, A M; Kosyk, O I; Taran, N Yu

2015-01-01

Buckwheat genus (Fagopyrum Mill.) is one of the aluminium tolerant taxonomic units of plants. The aim of the study was an evaluation of the aluminium (50 μM effect on phenolic accumulation in various parts of buckwheat plants (Fagopyrum esculentum Moench). Detection of increasing of total phenolic content, changes in flavonoid and anthocyanin content and phenylalanine ammonia-lyase activity (PAL) were revealed over a period of 10 days of exposure to aluminium. The most significant effects of aluminium treatment on phenolic compounds accumulation were total phenolic content increasing (by 27.2%) and PAL activity rising by 2.5 times observed in leaves tissues. Received data could be helpful to understand the aluminium tolerance principles and relationships of phenolic compounds to aluminium phytotoxicity.

PROCESS OF RECOVERING URANIUM FROM ITS ORES

Science.gov (United States)

Galvanek, P. Jr.

1959-02-24

A process is presented for recovering uranium from its ores. The crushed ore is mixed with 5 to 10% of sulfuric acid and added water to about 5 to 30% of the weight of the ore. This pugged material is cured for 2 to 3 hours at 100 to 110 deg C and then cooled. The cooled mass is nitrate-conditioned by mixing with a solution equivalent to 35 pounds of ammunium nitrate and 300 pounds of water per ton of ore. The resulting pulp containing 70% or more solids is treated by upflow percolation with a 5% solution of tributyl phosphate in kerosene at a rate equivalent to a residence time of about one hour to extract the solubilized uranium. The uranium is recovered from the pregnant organic liquid by counter-current washing with water. The organic extractant may be recycled. The uranium is removed from the water solution by treating with ammonia to precipitate ammonium diuranate. The filtrate from the last step may be recycled for the nitrate-conditioning treatment.

40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

Science.gov (United States)

2010-07-01

... subpart B are applicable to discharges from facilities engaged in the mining of bauxite as an aluminum ore. ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore...

Modelling of heterogeneous clustering in aluminium

International Nuclear Information System (INIS)

Smith, A.E.; Bourgeois, L.; Nie, J.-F.; Muddle, B.C.

2003-01-01

Full text: Ab initio modelling of heterogeneous clustering in aluminium has been carried out in order to study the precipitation hardening of alloys. This process is based on the addition of small amounts of solute element to the pure metal. With increasing computational power, atomic scale effects can now be better simulated to determine the nature of the hardening mechanism. Comparisons are made between results obtained from two computational packages. These are the Linear Augmented Plane Wave WEEN2K and the plane wave pseudopotential density functional theory package fhi98md. The study of the optimal geometry of very small size clusters inside aluminium has begun with the testing of initial convergence conditions by determination of binding energies for a variety of super cell sizes of the aluminium host crystal. These are compared with total energy calculations for small size precipitates of copper and transition metals of fixed geometry. Such local optimal determinations are seen as precursors to full Monte Carlo calculations of the notional best local geometry for larger precipitates

Radiometric sorting of Rio Algom uranium ore

International Nuclear Information System (INIS)

Cristovici, M.A.

1983-11-01

An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content ( 2 (2 counts/in 2 ) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm 2 (5-6 counts/in 2 ) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

Synthesis of aluminium nanoparticles by arc evaporation of an ...

Indian Academy of Sciences (India)

Administrator

Abstract. Aluminium nanoparticles (Al Nps) are synthesized using arc discharge method by applying direct current between aluminium electrodes in liquid environment without any use of vacuum equipment, heat exchangers, high temperatures furnaces and inert gases. After synthesis of Al Nps, in situ coating process on.

The varied functions of aluminium-activated malate transporters–much more than aluminium resistance

Science.gov (United States)

Palmer, Antony J.; Baker, Alison; Muench, Stephen P.

2016-01-01

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. PMID:27284052

Computer modelling of age hardening for cast aluminium alloys

International Nuclear Information System (INIS)

Wu, Linda; Ferguson, W George

2009-01-01

Age hardening, or precipitation hardening, is one of the most widely adopted techniques for strengthening of aluminium alloys. Although various age hardening models have been developed for aluminium alloys, from the large volume of literature reviewed, it appears that the bulk of the research has been concentrated on wrought aluminium alloys, only a few of the established precipitation models have been applied to the casting aluminium alloys. In the present work, there are two modelling methods that have been developed and applied to the casting aluminium alloys A356 and A357. One is based on the Shercliff-Ashby methodology to produce a process model, by which we mean a mathematical relationship between process variables (alloy composition, ageing temperature and time) and material properties (yield strength or hardness) through microstructure evolution (precipitate radius, volume fraction). The other method is based on the Kampmann and Wagner Numerical (KWN) model which deals with concomitant nucleation, growth and coarsening and is thus capable of predicting the full evolution of the particle size distribution and then a strength model is used to evaluate the resulting change in hardness or yield strength at room temperature by taking into account contributions from lattice resistance, solid solution hardening and precipitation hardening.

The genesis of ores

International Nuclear Information System (INIS)

Brimhall, G.

1991-01-01

Human history and technology have been shaped by metals. How did they become concentrated in minable deposits located so conveniently near the earth's surface? The author explains the mechanisms of fluid transport-by magma, water and even air and wind-responsible for the chemical and physical interactions that created bodies of metallic ores throughout geologic history. From their formation to their modification at the surface of the earth, ore deposits are geologically transitory and reflect dynamic processes within the earth as well as atmospheric and climatic influences on hydrologic systems. As highly reactive supracrustal systems, they then serve as geochemical sensors providing a powerful record and set of tracer elements for deducing the history, transport paths and forces operative in the crust

Geochemistry and ore prospecting

International Nuclear Information System (INIS)

Le Caignec, R.

1954-01-01

Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author) [fr

Light-weight aluminium bridges and bridge decks. An overview of recent applications

NARCIS (Netherlands)

Maljaars, J.; Soetens, F.; Kluyver, D. de

2008-01-01

The last decades have shown a large increase in the application of aluminium alloys for light-weight bridges. For bridge construction, aluminium alloys have some specific advantages, but also some points of attention. This paper deals with some recent projects of aluminium bridges, and for these

The geochemical characteristics of alkali metasomatic ore and its ore-forming significance at Zoujiashan deposit, Xiangshan uranium field

International Nuclear Information System (INIS)

Wang Yun; Hu Baoqun; Sun Zhanxue; Li Xueli; Guo Guolin; Rao Minghui

2012-01-01

Alkaline metasomatites are widely distributed in Zoujiashan uranium deposit and have close relation with uranium mineralization. Based on the study of field geological survey, petrographic methods, element chemical analysis and EPMA, etc, the alteration in alkaline metasomatic ore was found in the order of sodium metasomatism, potassium metasomatism and silica metasomatism. The alkaline hydrothermal fluid of mineralization is rich in Na at first and then rich in K, and quite similar in other chemical composition, but the K rich one is more favourite for the metallization. Compared with the normal porphyroclastic lava, the alkaline metasomatic ores in lower in SiO 2 , but higher in K 2 O or Na 2 O, Al 2 O 3 , Fe 2 O 3 , MgO, P 2 O 5 , CaO and U, Th, Zr, Hf, Sm, Ti, REE. Compared with potassium metasomatic ore, the sodium metasomatic ore is with high ΣLREE/ΣHREE ratio and lower Rb and REE. Because alkaline metasomatism is beneficial to release uranium from accessory mineral and bring out uranium from rocks, therefore it is very important to the migration and precipitation of uranium. (authors)

Improving the wettability of 2024 aluminium alloy by means of cold plasma treatment

Science.gov (United States)

Polini, W.; Sorrentino, L.

2003-05-01

Aluminium alloys are heavily used to manufacture structural parts in the aeronautic industry because of its lightness and its corrosion resistance. These alloys are successfully used in other industrial fields too, such as railway, automotive and naval industries. The need to contrast the severe use conditions and the heavy stresses developing in aeronautic field implies to protect the surfaces of the structures in aluminium alloy by any deterioration. To preserve by deterioration, it is necessary to make aluminium more suitable to be coated by protective paint. In the aeronautic industry, a complex and critical process is used in order to enhance both wettability and adhesive properties of aluminium alloy surfaces. Cold plasma treatment represents an efficient, clean and economic alternative to activate aluminium surfaces. The present work deals with air cold plasma treatment of 2024 aluminium alloy surfaces. The influence of dc electrical discharge cold plasma parameters on wettability of 2024 aluminium alloy surfaces has been studied. A set of process variables (voltage, time and air flow rate) has been identified and used to conduct some experimental tests on the basis of design of experiment (DOE) techniques. The experimental results show that the proposed plasma process may considerably increase aluminium alloy wettability. These results represent the first step in trying to optimise the aluminium adhesion by means of this non-conventional manufacturing process.

Effect of iron and silicon in aluminium and its alloys

International Nuclear Information System (INIS)

Kovacs, I.

1990-01-01

The iron and silicon are the main impurities in aluminium, they are always present in alloys made from commercially pure base material. The solid solubility of iron in aluminium is very low, therefore its largest amount forms intermetallic compounds the kind of which depends strongly on the other impurities of alloying elements. Although the solid solubility of silicon is much larger than that of the iron, it is the constituent of both the primary and the secondary particles, the structure of which depends in general on the iron-silicon concentration ratio. These Fe and Si containing particles can cause various and basic changes in the macroscopic properties of the alloy. Since commercially pure aluminium has extensive consumer and industrial use, it is very important to know, not only from scientific but also from practical point of view, the effect of iron and silicon on the physical and mechanical properties of aluminium and its alloys. The aim of the ''International Workshop on the Effect of Iron and Silicon in Aluminium and its Alloys'' was to clarify the present knowledge on this subject. The thirty papers presented at the Workshop and collected in this Proceedings cover many important fields of the subject. I hope that they will contribute to both the deeper understanding of the related phenomena and the improvement of technologies for producing better aluminium alloys

Microstructure and properties of aluminium-aluminium oxide graded composite materials

Science.gov (United States)

Kamaruzaman, F. F.; Nuruzzaman, D. M.; Ismail, N. M.; Hamedon, Z.; Iqbal, A. K. M. A.; Azhari, A.

2018-03-01

In this research works, four-layered aluminium-aluminium oxide (Al-Al2O3) graded composite materials were fabricated using powder metallurgy (PM) method. In processing, metal-ceramic graded composite materials of 0%, 10%, 20% and 30% weight percentage of ceramic concentration were prepared under 30 ton compaction load using a cylindrical die-punch set made of steel. After that, two-step pressureless sintering was carried out at sintering temperature and time 600°C and 3 hours respectively. It was observed that the sintered cylindrical specimens of 30 mm diameter were prepared successfully. The graded composite specimens were analysed and the properties such as density, microstructure and hardness were measured. It was found that after sintering process, the diameter of the graded cylindrical structure was decreased. Using both Archimedes method and rule of mixture (ROM), he density of structure was measured. The obtained results revealed that the microvickers hardness was increased as the ceramic component increases in the graded layer. Moreover, it was observed that the interface of the graded structure is clearly distinguished within the multilayer stack and the ceramic particles are almost uniformly distributed in the Al matrix.

Development of an on-line electrochemical analyser for trace level aluminium

International Nuclear Information System (INIS)

Chow, Christopher W.K.; Thomas, Shaun D.; Davey, David E.; Mulcahy, Dennis E.; Drikas, Mary

2003-01-01

An in-house designed computerised flow injection (FI) system for low-level aluminium analysis is examined. A simple, low cost electrochemical detection system has been implemented with computerised control and data acquisition system. The system consists of a commercial electrochemical analyser, FI components (manifold, pumps and valves) and an in-house designed control system to perform automated analysis. This system was developed to study aluminium speciation in water, particularly for drinking water. The analytical technique was based upon the complexation reaction between aluminium and a ligand--DASA (1,2-dihydroxy-anthraquinone-3-sulphonic acid). 'Labile' and total aluminium concentrations, Al labile and Al total , respectively, were determined by measuring the sample before and after UV irradiation by amperometry at +0.6 V. The limit of detection for this technique was 10 μg/l (0.37 μM) and the linear calibration range was up to 1.6 mg/l (60 μM) with r 2 value of 0.999. The Al labile /Al total ratios of the water treated by 40, 80 and 100 mg/l of alum using a laboratory scale pilot plant to simulate conventional drinking water treatment processes were found to be 0.4, 0.5 and 0.8, respectively. These results indicated that when higher alum dose was employed, the residual aluminium was present mostly as the 'labile' species. Whereas, if the treatment process was not running at its optimum condition (underdosing), a large portion of aluminium was present as natural organic matter (NOM) - aluminium complexes in the treated water. The system offers a practical and effective means of providing extended knowledge of residual aluminium in drinking water

Aluminium Matrix Composites Reinforced with Co-continuous Interlaced Phases Aluminium-alumina Needles

Directory of Open Access Journals (Sweden)

Elvio de Napole Gregolin

2002-09-01

Full Text Available An Al-5SiO2 (5 wt% of SiO2 aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM and optical microscopy on polished and fractured samples.

Status Report from Czechoslovakia [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Civin, V; Belsky, M [Research and Development Laboratory No.3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

1967-06-15

The present paper deals with the fundamental problems and the main routes followed in processing low-grade uranium ores in CSSR. In this connection it may be useful to discuss the definition of low-grade ore. In our country this term is applied to uraniferous material with a very low content of uranium (of the order of 0.01%) whose treatment causes no particular difficulty. However, the same term is also used to designate those materials whose processibility lies on the verge of economic profitability. In our view, this classification, of an ore using two independent criteria (i.e. uranium content and processing economy) is useful from the standpoint of technology. The treatment of both such ore types is as a rule carried out by specific technological processes. Consequently, low-grade uranium ores can be divided into two groups: (1) Ores with a low uranium content. To this category belong in our country uraniferous materials which originate as a by-product of technological processes used in processing other materials. This is primarily gangue and tailings of various physical or physico-chemical pretreatment operations to which the ore is subjected at the mining site. Mention should be made in this connection of mine waters, which represent a useful complementary source of uranium despite their low uranium content (of the order of milligrams per litre). (2) Ores whose economical treatment is problematic. To this category belong deposits of conventional ore types with a uranium content on the limit of profitable treatment. Also, those deposits containing atypical materials possessing such properties which impair the economy of their treatment. This includes ores with a considerable amount of components which are difficult to separate and which at the same time consume the leaching agents. Finally, it covers uranium-bearing materials in refractory forms which are difficult to dissolve and also some special materials, such as lignites, uranium-bearing shales, loams

Preparation of polymeric aluminium ferric chloride from bauxite tailings

Directory of Open Access Journals (Sweden)

Ma D.

2013-01-01

Full Text Available Bauxite tailings are the main solid wastes in the ore dressing process. The Al2O3 and Fe2O3 contents in bauxite tailings can reach 50% and 13% respectively. The present study proposed a feasible method to use bauxite tailings to prepare polymeric aluminium ferric chloride (PAFC, a new composite inorganic polymer for water purification. Bauxite tailings roasted reacting with hydrochloric acid under air, pickle liquor which mainly contains Fe3+, Al3+ was generated, then calcium aluminate was used to adjust pH value and the basicity of the pickle liquor, the PAFC was subsequently prepared after the polymerization process. The optimal synthesizing parameters for the preparation of PAFC obtained were as follows: the concentration of hydrochloric acid of 24 wt%, ratio of hydrochloric acid to bauxite tailings of 6:1, temperature of 90ºC, leaching time of 2.5 hours, ration of pickle liquor to calcium aluminate of 12:1, polymerization temperature of 90ºC and polymerization time of about 3 hours. The basicity of PAFC was higher than 68%, the sum concentration of Al2O3 and Fe2O3 was beyond 12.5%. The results of flocculation tests indicate that the PAFC has a better performance of removing the turbidity of wastewater compared to PAC, and PAFC prepared by bauxite tailings is a kind of high quality flocculants.

Uranium ore processing minimizing reagent losses

International Nuclear Information System (INIS)

Shaogiang, Chen; Moret, J.; Lyaudet, G.

1989-01-01

The uranium ore is treated by sodium carbonates and the solution is divided in two parts: a production solution which is decarbonated by an acid before uranium precipitation with sodium hydroxide and a recycling solution directly treated by sodium hydroxide for precipitation of about 85% of uranium and total transformation of sodium bicarbonate into sodium carbonate, the quantity of sodium hydroxide used on the recycling solution brings sodium ions required for attack of the ore [fr

Aluminium alloys in municipal solid waste incineration bottom ash.

Science.gov (United States)

Hu, Yanjun; Rem, Peter

2009-05-01

With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

Trace aluminium determination and sampling problems of archeological bone employing destructive neutron activation analysis

International Nuclear Information System (INIS)

Blotcky, A.J.; Rack, E.P.; Recker, R.R.; Leffler, J.A.; Teitelbaum, S.

1978-01-01

A destructive neutron activation analysis procedure was developed for determining trace aluminium content in bone. The method is based on a carefully planned sample preparation, irradiation at a neutron flux for 3.1x10 11 nxcm -2 xs -1 for 5 minutes, and chemical separation based on ion exchange. It was found that bone samples soaked in aluminium containing soil gave highly elevated aluminium values as a result of the aluminium adsorption into the bone matrix. The maximum aluminium content values for prehistoric bones are larger than those of modern bones and comparable to aluminium levels present in bone from renal patients. (T.G.)

Fire exposed aluminium structures

NARCIS (Netherlands)

Maljaars, J.; Fellinger, J.E.J.; Soetens, F.

2005-01-01

Material properties and mechanical response models for fire design of steel structures are based on extensive research and experience. Contrarily, the behaviour of aluminium load bearing structures exposed to fire is relatively unexplored. This article gives an overview of physical and mechanical

Hydrogen Plasma Processing of Iron Ore

Science.gov (United States)

Sabat, Kali Charan; Murphy, Anthony B.

2017-06-01

Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

Manufacturing and Machining Challenges of Hybrid Aluminium Metal Matix Composites

Science.gov (United States)

Baburaja, Kammuluri; Sainadh Teja, S.; Karthik Sri, D.; Kuldeep, J.; Gowtham, V.

2017-08-01

Manufacturing which involves material removal processes or material addition processes or material transformation processes. One or all the processes to obtain the final desired properties for a material with desired shape which meets the required precision and accuracy values for the expected service life of a material in working conditions. Researchers found the utility of aluminium to be the second largest after steel. Aluminium and its metal matrix composite possess wide applications in various applications in aerospace industry, automobile industry, Constructions and even in kitchen utensils. Hybrid Al-MMCconsist of two different materials, and one will be from organic origin along with the base material. In this paper an attempt is made to bring out the importance of utilization of aluminium and the challenges concerned in manufacturing and machining of hybrid aluminium MMC.

Chemical mimicking of bio-assisted aluminium extraction by Aspergillus niger's exometabolites.

Science.gov (United States)

Boriová, Katarína; Urík, Martin; Bujdoš, Marek; Pifková, Ivana; Matúš, Peter

2016-11-01

Presence of microorganisms in soils strongly affects mobility of metals. This fact is often excluded when mobile metal fraction in soil is studied using extraction procedures. Thus, the first objective of this paper was to evaluate strain Aspergillus niger's exometabolites contribution on aluminium mobilization. Fungal exudates collected in various time intervals during cultivation were analyzed and used for two-step bio-assisted extraction of alumina and gibbsite. Oxalic, citric and gluconic acids were identified in collected culture media with concentrations up to 68.4, 2.0 and 16.5 mmol L -1 , respectively. These exometabolites proved to be the most efficient agents in mobile aluminium fraction extraction with aluminium extraction efficiency reaching almost 2.2%. However, fungal cultivation is time demanding process. Therefore, the second objective was to simplify acquisition of equally efficient extracting agent by chemically mimicking composition of main organic acid components of fungal exudates. This was successfully achieved with organic acids mixture prepared according to medium composition collected on the 12th day of Aspergillus niger cultivation. This mixture extracted similar amounts of aluminium from alumina compared to culture medium. The aluminium extraction efficiency from gibbsite by organic acids mixture was lesser than 0.09% which is most likely because of more rigid mineral structure of gibbsite compared to alumina. The prepared organic acid mixture was then successfully applied for aluminium extraction from soil samples and compared to standard single step extraction techniques. This showed there is at least 2.9 times higher content of mobile aluminium fraction in soils than it was previously considered, if contribution of microbial metabolites is considered in extraction procedures. Thus, our contribution highlights the significance of fungal metabolites in aluminium extraction from environmental samples, but it also simplifies the

Electrical connection for aluminium conductors in automotive applications : Prestudy of available solutions for electrical connection methods of aluminium cables

OpenAIRE

Hamedi, Emilia

2017-01-01

Due to increasing weight of electrical component and wiring harnesses in a vehicle contrary to the demand of light constructed vehicles as well as the constantly increasing and fluctuating price of copper compared to aluminium’s stable and far lower price, the use of aluminium conductors as an alternative have been promoted.  This thesis work lay theoretical research of the available methods used for electrical connection of aluminium conductors in order to increase the knowledge about the av...

Measurement of oxide-layer thickness of internal granules in high-purity aluminium

International Nuclear Information System (INIS)

Takacs, S.; Ditroi, F.; Mahunka, I.

1989-01-01

Charged-particle activation analysis was used for the determination of bulk oxygen concentration in aluminium. High-purity aluminium samples and mixtures containing different amounts of alumina were irradiated by 13 MeV 3 He particles. The aim of the investigation was to determine the oxide-layer thickness on the surface of internal aluminium granules. The measurement was carried out by determining the bulk oxygen concentration in the samples, and calculating the oxide-layer thickness, by using model conditions about the microstructure of the aluminium samples. (author) 5 refs

The potential for ore and industrial minerals in the Forsmark area

Energy Technology Data Exchange (ETDEWEB)

Lindroos, Hardy [MIRAB Mineral Resurser AB, Uppsala (Sweden); Isaksson, Hans; Thunehed, Hans [GeoVista AB, Luleaa (Sweden)

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc

The potential for ore and industrial minerals in the Forsmark area

International Nuclear Information System (INIS)

Lindroos, Hardy; Isaksson, Hans; Thunehed, Hans

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc, although

The varied functions of aluminium-activated malate transporters-much more than aluminium resistance.

Science.gov (United States)

Palmer, Antony J; Baker, Alison; Muench, Stephen P

2016-06-15

The ALMT (aluminium-activated malate transporter) family comprises a functionally diverse but structurally similar group of ion channels. They are found ubiquitously in plant species, expressed throughout different tissues, and located in either the plasma membrane or tonoplast. The first family member identified was TaALMT1, discovered in wheat root tips, which was found to be involved in aluminium resistance by means of malate exudation into the soil. However, since this discovery other family members have been shown to have many other functions such as roles in stomatal opening, general anionic homoeostasis, and in economically valuable traits such as fruit flavour. Recent evidence has also shown that ALMT proteins can act as key molecular actors in GABA (γ-aminobutyric acid) signalling, the first evidence that GABA can act as a signal transducer in plants. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Corrosion of research reactor aluminium clad spent fuel in water

International Nuclear Information System (INIS)

2003-01-01

This report describes research performed in ten laboratories within the framework of the IAEA Co-ordinated Research Project on Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water. The project consisted of exposure of standard racks of corrosion coupons in the spent fuel pools of the participating research reactor laboratories and the evaluation of the coupons after predetermined exposure times, along with periodic monitoring of the storage water. A group of experts in the field contributed a state of the art review and provided technical supervision of the project. Localized corrosion mechanisms are notoriously difficult to understand, and it was clear from the outset that obtaining consistency in the results and their interpretation from laboratory to laboratory would depend on the development of an excellent set of experimental protocols. These experimental protocols are described in the report together with guidelines for the maintenance of optimum water chemistry to minimize the corrosion of aluminium clad research reactor fuel in wet storage. A large database on corrosion of aluminium clad materials has been generated from the CRP and the SRS corrosion surveillance programme. An evaluation of these data indicates that the most important factors contributing to the corrosion of the aluminium are: (1) High water conductivity (100-200 μS/cm); (2) Aggressive impurity ion concentrations (Cl - ); (3) Deposition of cathodic particles on aluminium (Fe, etc.); (4) Sludge (containing Fe, Cl - and other ions in concentrations greater than ten times the concentrations in the water); (5) Galvanic couples between dissimilar metals (stainless steel-aluminium, aluminium-uranium, etc); (6) Scratches and imperfections (in protective oxide coating on cladding); (7) Poor water circulation. These factors operating both independently and synergistically may cause corrosion of the aluminium. The single most important key to preventing corrosion is maintaining good

Technique for in situ leach simulation of uranium ores

International Nuclear Information System (INIS)

Grant, D.C.; Seidel, D.C.; Nichols, I.L.

1985-01-01

In situ uranium mining offers the advantages of minimal environmental disturbance, low capital and operating costs, and reduced mining development time. It is becoming an increasingly attractive mining method for the recovery of uranium from secondary ore deposits. In order to better understand the process, a laboratory technique was developed and used to study and simulate both the chemical and physical phenomena occurring in ore bodies during in situ leaching. The laboratory simulation technique has been used to determine effects of leaching variables on permeability, uranium recovery, and post-leach aquifer restoration. This report describes the simulation system and testing procedure in sufficient detail to allow the construction of the system, and to perform the desired leaching tests. With construction of such a system, in situ leaching of a given ore using various leach conditions can be evaluated relatively rapidly in the laboratory. Not only could optimum leach conditions be selected for existing ore bodies, but also exploitation of new ore bodies could be accelerated. 8 references, 8 figures, 2 tables

Electrotransport of hydrogen in aluminium at 20 and 800 deg C

International Nuclear Information System (INIS)

Byalik, O.M.; Volkotrub, N.P.; Pinchuk, V.M.; Golub, L.V.; Degtyarenko, G.E.; Ivanchuk, D.F.

1982-01-01

Electrotransport of hydrogen in the field of crystal lattice of aluminium is investigated at the special installation using the method of measurement of electric resistivity. Quantum-mechanical calculation of H + and H - ions interaction with aluminium atoms is made to clarify the mechanizm of electrotransport. It is shown, that probability of the H + and H - ions permeation in the field of aluminium crystal lattice can be judged by the ratio of δE 1 (the lattice potential barrier) and δ 2 (the local energy minium in the case of atom arrangement in the lattice plane). The value of potentials of hydrogen ions interaction with aluminium lattice is obtained in the result os solution of the Schroedinger equation

Economic outlook for radiometric selection of ores

International Nuclear Information System (INIS)

Formery, P.; Ziegler, V.

1958-01-01

The value of an ore can be increased by cutting off it's poor fractions. This selection may be realized at two stages: - part of the ore in situ is unable to cover it's extraction and treatment costs, this defines the 'underground cut-off grade'; - another portion of already extracted ore is unable to cover it's transport and treatment costs; this defines the 'surface cut off grade'. These selections are easily feasible owing to the property of uranium ores of emitting gamma radiations. A diagram makes possible a fast forecast on the effect of this selection upon the weight and metal yields. An attempt is made as well in order to provide the expected effect of the composition of underground cut off and surface cut off. This cut off however, being realized through an appreciation of the radiations, involves an alteration of the weight and metal yields which calls for a correction. A survey of the economic interest of the cut-off is done and an example of valorisation in a given deposit of a section at the limit of operability is proposed. (author) [fr

AE Monitoring of Diamond Turned Rapidly Soldified Aluminium 443

International Nuclear Information System (INIS)

Onwuka, G; Abou-El-Hossein, K; Mkoko, Z

2017-01-01

The fast replacement of conventional aluminium with rapidly solidified aluminium alloys has become a noticeable trend in the current manufacturing industries involved in the production of optics and optical molding inserts. This is as a result of the improved performance and durability of rapidly solidified aluminium alloys when compared to conventional aluminium. Melt spinning process is vital for manufacturing rapidly solidified aluminium alloys like RSA 905, RSA 6061 and RSA 443 which are common in the industries today. RSA 443 is a newly developed alloy with few research findings and huge research potential. There is no available literature focused on monitoring the machining of RSA 443 alloys. In this research, Acoustic Emission sensing technique was applied to monitor the single point diamond turning of RSA 443 on an ultrahigh precision lathe machine. The machining process was carried out after careful selection of feed, speed and depths of cut. The monitoring process was achieved with a high sampling data acquisition system using different tools while concurrent measurement of the surface roughness and tool wear were initiated after covering a total feed distance of 13km. An increasing trend of raw AE spikes and peak to peak signal were observed with an increase in the surface roughness and tool wear values. Hence, acoustic emission sensing technique proves to be an effective monitoring method for the machining of RSA 443 alloy. (paper)

Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

Science.gov (United States)

Smith-Schmitz, Sarah E.; Appold, Martin S.

2018-03-01

Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba

Environmental nuclear-geophysical ore monitoring in mines of Corporation Kazakhmys PLC.

Science.gov (United States)

Yefimenko, Sergei; Yefimenko, Olga; Makarov, Dmitriy

2014-01-01

An environmental monitoring of ore composition in complex deposits of Kazakhstan (the Zhezkazgan, Kusmuryn, Artemjevsk, Kounrad, Taskura and Zhaman-Aibat deposits) is carried out using EDXRF spectrometers RPP-12, RLP-21 and RLP-21T. The monitoring of ore concentrates in Satpaev, Balkhashsk and Zhezkazgan processing plants and in Zhezkazgan copper smelter continues at present time. The monitoring suggests data on new promising elements and environmental pollutants in ores and new trends in distribution of bound elements in ores.

Potential for cobalt recovery from lateritic ores in Europe

Science.gov (United States)

Herrington, R.

2012-04-01

Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

Sol gel synthesis for preparation of yttrium aluminium garnet

NARCIS (Netherlands)

Vrolijk, J.W.G.A.; Willems, J.W.M.M.; Metselaar, R.; With, de G.; Terpstra, R.A.; Metselaar, R.

1989-01-01

Sol-gel—synthesis for preparation of pure yttrium aluminium garnet powder with small grain size is subject of this ongoing study. Starting materials were sulfates and chlorides of yttrium and aluminium. To obtain pure YAG (Y3A1SO1Z) pH during hydrolysis as well as temperature during calcination and

Defect generation during solidification of aluminium foams

International Nuclear Information System (INIS)

Mukherjee, M.; Garcia-Moreno, F.; Banhart, J.

2010-01-01

The reason for the frequent occurrence of cell wall defects in metal foams was investigated. Aluminium foams often expand during solidification, a process which is referred as solidification expansion (SE). The effect of SE on the structure of aluminium foams was studied in situ by X-ray radioscopy and ex situ by X-ray tomography. A direct correlation between the magnitude of SE and the number of cell wall ruptures during SE and finally the number of defects in the solidified foams was found.

Aluminium, extractable from soil samples by the acid ammonium acetate soil-testing method

Directory of Open Access Journals (Sweden)

Osmo Mäkitie

1968-05-01

Full Text Available The extractant, 0.5 M acetic acid –0.5 M ammonium acetate at pH 4.65, which is used in soil-testing, extracts relatively high amounts of aluminium from acid soils. The mean values of acetate-extractable aluminium at pH 4.65, 1.75 meq Al/100 g of soil, and of exchangeable aluminium (M KCI extraction, 0.41 meq Al were obtained from a material of 30 samples of acid soils (Table 2. Several other acetic acid ammonium acetate extractants, from M acetic acid to M ammonium acetate solution were also used for studying the extractability of soil aluminium. The soil-testing extractant can be used for the estimation of the soluble amounts of aluminium in acid soils, however, further studies are needed for a better interpretation of the ammonium acetate extractable (at pH 4.65 aluminium in our soils.

Challenges facing the North American iron ore industry

Science.gov (United States)

Jorgenson, J.D.

2005-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

Factors affecting the aluminium content of human femoral head and neck.

Science.gov (United States)

Zioła-Frankowska, Anetta; Dąbrowski, Mikołaj; Kubaszewski, Łukasz; Rogala, Piotr; Frankowski, Marcin

2015-11-01

Tissues for the study were obtained intraoperatively during hip replacement procedures from 96 patients. In all the cases, the indication for this treatment was primary or secondary degenerative changes in the hip joint. The subject of the study was the head and neck of the femur, resected in situ. Aluminium concentrations measured in femoral head and neck samples from patients aged between 25 and 91 were varied. Statistical methods were applied to determine the variations in relation to the parameters from the background survey. Significant differences in the aluminium content of femoral head samples were observed between patients under and over 60 years of age. Based on the results, it was confirmed that the aluminium accumulates in bones over a lifetime. The study showed that the content of aluminium in the head and neck of the femur depends on the factors such as: type of medicines taken, contact with chemicals at work, differences in body anatomy and sex. The study on the levels of aluminium in bones and the factors affecting its concentration is a valuable source of information for further research on the role of aluminium in bone diseases. Based on the investigations, it was found that the GF-AAS technique is the best analytical tool for routine analysis of aluminium in complex matrix samples. The use of femoral heads in the investigations was approved by the Bioethics Committee of the University of Medical Sciences in Poznań (Poland). Copyright © 2015 Elsevier Inc. All rights reserved.

Crystal structure and phase composition of aluminium thin films with holmium additions

International Nuclear Information System (INIS)

Koleshko, V.M.; Belitskij, V.F.; Obukhov, V.E.; Rumak, N.V.; Urban, T.P.

1984-01-01

The effect of holmium additions on the crystal structure and phase composition of thin aluminium films has been studied. A regularity in grain size changes in aluminium thin films versus the holmium content in them is established. The holmium introduction is shown to result in the appearance of axial texture in the aluminium films, the texture axis being determined by the quantity of the addition. During heat treatment of the aluminium films, containing holmium additions, in the range of low ( approximately 100-200 deg C) annealing temperatures holmium monohydroxide is formed, and at annealing temperatures 300 deg C 0 3 is formed

Comparison of oxidants in alkaline leaching of uranium ore

International Nuclear Information System (INIS)

Sreenivas, T.; Rajan, K.C.; Srinivas, K.; Anand Rao, K.; Manmadha Rao, M.; Venkatakrishnan, R.R.; Padmanabhan, N.P.H.

2007-01-01

The uranium minerals occurring in various ore deposits consists of predominantly uranous ion (U +4 ), necessitating use of an oxidant and other lixiviants for efficient dissolution during leaching. Unlike acid leaching route, where uranium minerals dissolution could be achieved efficiently with cheaper lixiviants, processing of ores by alkaline leaching route involve expensive lixiviants and drastic leaching conditions. Alkaline leaching of uranium ores becomes economical only upon using cheaper and efficient oxidants and conservation of other reagents by their recycle. The present paper gives efficacy of various oxidants - KMnO 4 , NaOCl, Cu - NH 3 , air and oxygen, in the leaching of uranium from a low-grade dolostone hosted uranium ore of India. A comparison based on technical merits and cost of the oxidant chemicals is discussed. (author)

Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

Science.gov (United States)

Henda, R; Hermas, A; Gedye, R; Islam, M R

2005-01-01

A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

The effects of aluminium and selenium supplementation on brain ...

African Journals Online (AJOL)

This in vivo study was designed to investigate the potential of aluminium (Al), in the absence of added iron, to participate in either antioxidant or pro-oxidant events. Some markers of oxidative stress were determined in liver and brain of rats exposed to aluminium lactate, either alone or in the presence of dietary supplements ...

Potentiometric determination of the 'formal' hydrolysis ratio of aluminium species in aqueous solutions

International Nuclear Information System (INIS)

Fournier, Agathe C.; Shafran, Kirill L.; Perry, Carole C.

2008-01-01

The 'formal' hydrolysis ratio (h = C(OH - ) added /C(Al) total ) of hydrolysed aluminium-ions is an important parameter required for the exhaustive and quantitative speciation-fractionation of aluminium in aqueous solutions. This paper describes a potentiometric method for determination of the formal hydrolysis ratio based on an automated alkaline titration procedure. The method uses the point of precipitation of aluminium hydroxide as a reference (h = 3.0) in order to calculate the initial formal hydrolysis ratio of hydrolysed aluminium-ion solutions. Several solutions of pure hydrolytic species including aluminium monomers (AlCl 3 ), Al 13 polynuclear cluster ([Al 13 O 4 (OH) 24 (H 2 O) 12 ] 7+ ), Al 30 polynuclear cluster ([Al 30 O 8 (OH) 56 (H 2 O) 26 ] 18+ ) and a suspension of nanoparticulate aluminium hydroxide have been used as 'reference standards' to validate the proposed potentiometric method. Other important variables in the potentiometric determination of the hydrolysis ratio have also been optimised including the concentration of aluminium and the type and strength of alkali (Trizma-base, NH 3 , NaHCO 3 , Na 2 CO 3 and KOH). The results of the potentiometric analysis have been cross-verified by quantitative 27 Al solution nuclear magnetic resonance ( 27 Al NMR) measurements. The 'formal' hydrolysis ratio of a commercial basic aluminium chloride has been measured as an example of a practical application of the developed technique

Water leaching of titanium from ore flotation residue.

Science.gov (United States)

Jaworska, Malgorzata M; Guibal, Eric

2003-01-01

Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

Arsenic bioleaching in medical realgar ore and arsenicbearing ...

African Journals Online (AJOL)

However, the maximum arsenic leaching ratio from realgar in the presence of mixed unadapted strains was only 12.4 %. Besides, maximum arsenic leaching ratios from arsenic-bearing refractory gold ore by mixed adapted strains or unadapted strains were 45.0 and 22.9 %, respectively. Oxidation of these two ores by ...

Aluminium concentration versus the base cation to aluminium ratio as predictors for aluminium toxicity in Pinus sylvestris and Picea abies seedlings

NARCIS (Netherlands)

Schöll, van L.; Keltjens, W.G.; Hoffland, E.; Breemen, van N.

2004-01-01

Aluminium (Al) toxicity is considered an important factor in forest deterioration caused by soil acidification. A ratio of base cations (BC) to Al in the soil solution lower than 1 is widely used as an indicator for potentially adverse effects on tree health. In our view, the validity of the

Effect of microcrystallization on pitting corrosion of pure aluminium

International Nuclear Information System (INIS)

Meng Guozhe; Wei Liyan; Zhang Tao; Shao Yawei; Wang Fuhui; Dong Chaofang; Li Xiaogang

2009-01-01

A microcrystalline aluminium film with grain size of about 400 nm was prepared by magnetron sputtering technique. Its corrosion behaviour was investigated in NaCl containing acidic solution by means of potentiodynamic polarization curves and electrochemical noise (EN). The polarization results indicated that the corrosion potential of the sample shifted towards more positive direction, while its corrosion current density decreased compared with that of pure coarse-grain Al. The EN analysis based on stochastic model demonstrated that there existed two kinds of effect of microcrystallization on the pitting behaviour of pure aluminium: (1) the rate of pit initiation is accelerated, (2) the pit growth process was impeded. This leads to the enhancement of pitting resistance for the microcrystallized aluminium.

Three body abrasion of laser surface alloyed aluminium AA1200

CSIR Research Space (South Africa)

Mabhali, Luyolo AB

2012-06-01

Full Text Available Laser surface alloying of aluminium AA1200 was performed with a 4 kW Nd:YAG laser to improve the abrasion wear resistance. Aluminium surfaces reinforced with metal matrix composites and intermetallic phases were achieved. The phases present depended...

Neutron activation analysis of baths forming conversion layer on aluminium

International Nuclear Information System (INIS)

Szilagyi, Istvan; Maleczki, Emil; Bodizs, Denes

1988-01-01

Chromate layers were formed on the surface of aluminium using yellow and green chromating solutions. For the determination of the aluminium content neutron activation method was used. Nuclear effects disturbing the determination were eliminated by double irradiation technique. (author) 8 refs.; 4 figs

Dietary exposure to aluminium and health risk assessment in the residents of Shenzhen, China.

Science.gov (United States)

Yang, Mei; Jiang, Lixin; Huang, Huiping; Zeng, Shengbo; Qiu, Fen; Yu, Miao; Li, Xiaorong; Wei, Sheng

2014-01-01

Although there are great changes of dietary in the past few decades in China, few are known about the aluminium exposure in Chinese diet. The aim of this study is to systematically evaluate the dietary aluminium intake level in residents of Shenzhen, China. A total of 853 persons from 244 household were investigated their diet by three days food records. Finally, 149 kinds of foods in 17 food groups were selected to be the most consumed foods. From them, 1399 food samples were collected from market to test aluminium concentration. High aluminium levels were found in jellyfish (median, 527.5 mg/kg), fried twisted cruller (median, 466.0 mg/kg), shell (median, 107.1 mg/kg). The Shenzhen residents' average dietary aluminium exposure was estimated at 1.263 mg/kg bw/week which is lower than the PTWI (provisional tolerable weekly intake). But 0-2 and 3-13 age groups have the highest aluminium intake exceeding the PTWI (3.356 mg/kg bw/week and 3.248 mg/kg bw/week) than other age groups. And the main dietary aluminium exposure sources are fried twisted cruller, leaf vegetables and bean products. Our study suggested that even three decades rapid economy development, children in Shenzhen still have high dietary aluminium exposure risk. How to control high dietary aluminium exposure still is a great public health challenge in Shenzhen, China.

Decomposition of oxidezed lead and aluminium thin films on molybdenum substrates

International Nuclear Information System (INIS)

Makarovskij, N.A.

1981-01-01

The decomposition of oxidized solid phase lead and aluminium thin films on molybdenum substrates in the process of diffusion annealing in the 5x10 -5 mm Hg vacuum at temperatures from 280 to 320 deg C and from 500 to 560 deg C, respectively, is investigated. The conclusion is made that failure of oxidized lead and aluminium thin film coatings is carried out by the mechanism of volumetric self-diffusion. Experimentally established values of activation energies of the process of lead (Qsub(Mo)sup(Pb)=29 kcal/mol) and aluminium (Qsub(Mo)sup(Al)=35 kcal/mol) film failure are close to corresponding activation energies of lead and aluminium volumetric self-diffusion, which agrees with the conclusions made [ru

Corrosion Inhibition of Aluminium in Acid Media By Citrullus Colocynthis Extract

Directory of Open Access Journals (Sweden)

Rajkiran Chauhan

2011-01-01

Full Text Available Inhibition of corrosion of aluminium in acid solution by methanol extract of Citrullus colocynthis plant has been studied using mass loss and thermometric measurements. It has been found that the plant extract act as a good corrosion inhibitor for aluminium in all concentrations of sulphuric and hydrochloric acid solution. The inhibition action depends on the concentration of acid and inhibitor. Results for mass loss and thermometric measurement indicate that inhibition efficiency increase with increasing inhibitor concentration. The inhibition action of the plant extract is discussed in view of Langmuir adsorption isotherm. It has been observed that the adsorption of the extract on aluminium surface is a spontaneous process. The plant extract provides a good protection to aluminium against corrosion.

Method of preparing an Al-Ti-B grain refiner for aluminium-comprising products, and a method of casting aluminium products

OpenAIRE

Brinkman, H.J.; Duszczyk, J.; Katgerman, L.

1999-01-01

The invention relates to a method of preparing an Al-Ti-B grain refiner for cast aluminium-comprising products. According to the invention the preparation is realized by mixing powders selected from the group comprising aluminium, titanium, boron, and alloys and intermetallic compounds thereof, compressing, heating in an inert environment until an exothermic reaction is initiated and cooling. It has been shown that when the grain refiner thus prepared is applied, the quality of cast products ...

40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability;...

Proposal for selecting an ore sample from mining shaft under Kvanefjeld

International Nuclear Information System (INIS)

Lund Clausen, F.

1979-02-01

Uranium ore recovered from the tunnel under Kvanefjeld (Greenland) will be processed in a pilot plant. Selection of a fully representative ore sample for both the whole area and single local sites is discussed. A FORTRAN program for ore distribution is presented, in order to enable correct sampling. (EG)

Measurement and Modelling of Blast Movement to Reduce Ore ...

African Journals Online (AJOL)

user

geologists at Newmont Ahafo Mine have realised the impact of blast movement on ore losses and dilution and have ... Movement to Reduce Ore Losses and Dilution at Ahafo Gold Mine in Ghana”, Ghana Mining Journal, pp. .... classification.

An aluminium evaporation source for ion plating

International Nuclear Information System (INIS)

Walley, P.A.; Cross, K.B.

1977-01-01

Ion plating with aluminium is becoming increasingly accepted as a method of anti-corrosion surface passivation, the usual requirements being for a layer between 12 and 50 microns in thickness, (0.0005 to 0.002). The evaporation system described here offers a number of advantages over high power electron beam sources when used for aluminium ion plating. The source consists of a resistively heated, specially shaped, boron nitride-titanium diboride boat and a metering feed system. Its main features are small physical size, soft vacuum compatibility, low power consumption and metered evaporation output. (author)

Bioactive type glass-ceramics within incorporated aluminium

International Nuclear Information System (INIS)

Volzone, C.; Stabile, F.M.; Ortiga, J.

2012-01-01

Bioactive glass-ceramics are used as biomaterials for the reparation of bone tissue. They are prepared, generally, by bioglass of specific composition for each particular use. The aluminium addition in the formulation at very small quantities influences on the structural properties. Two glass-ceramics obtained by P 2 O 5 -Na 2 O-CaO-SiO 2 formulation within aluminium (0.5 % in Al 2 O 3 base) added through a reactive alumina and purified feldspar were analyzed. The results showed structural differences between both glass-ceramics. (author)

Treatment of bastnaesite ore from Vietnamese Socialist Republic

International Nuclear Information System (INIS)

Formanek, J.; Jerabek, J.; Jancarek, J.

1987-01-01

From the Vietnamese deposit at Nam Nam Xe Czechoslovakia imported several hundred tons of ore. Several methods of ore dressing were used: gravitational, preconcentration in electromagnetic field, magnetic separation, high-intesity electromagnetic separation. Flotation evidently was the best dressing method tried. The results are presented of testing using different flotation agents. (E.S.)

Mineralogical study of zard koh and kulli koh iron ore deposits of pakistan

International Nuclear Information System (INIS)

Khoso, S.A.; Abro, M.I.

2017-01-01

Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited) is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SEM (Scanning Electron Microscope) attached with EDS (Energy Dispersive Spectroscope) and SM (Stereomicroscope) techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques. (author)

Uranium and thorium recovery in thorianite ore-preliminary results

Energy Technology Data Exchange (ETDEWEB)

Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

2011-07-01

This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

Aluminium-rich corner in Al-Cu-La system

International Nuclear Information System (INIS)

Yunusov, I.; Ganiev, I.N.

1990-01-01

Aluminium corner of Al-Cu-La system are investigated by means of microstructural and differential thermal analysis. Existence of LaCu 2 Al 10 and LaCu 0.5 Al 3.5 ternary compounds in the system is confirmed and it is shown, as well, both compounds are in two-phase equilibrium with aluminium solid solution and form with it and between each other eutectic type state diagrams. State diagrams for quasibinary sections are plotted

Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content

International Nuclear Information System (INIS)

Mouturat, P.

1966-06-01

The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author) [fr

Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

Directory of Open Access Journals (Sweden)

Mathivanan Periasamy

2012-06-01

Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

Decomposition of silica-alumina ores of Afghanistan by sulfuric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2016-01-01

Present article is devoted to decomposition of silica-alumina ores of Afghanistan by sulfuric acid. Physicochemical properties of initial silica-alumina ores were studied by means of X-ray phase, differential thermal and silicate analysis. The influence of temperature, process duration and acid concentration on extraction rate of valuable components was considered. The optimal conditions of decomposition of silica-alumina ores of Afghanistan by sulfuric acid were proposed.

Residues leaching from 'Factory of barren ores'

International Nuclear Information System (INIS)

Rakhmatov, N.; Khakimov, N.; Nazarov, Kh.M.; Barotov, A.M.

2012-01-01

The objective of the present work is safe management of residues from Factory of Barren Ores, their reprocessing, expenditures reduction for remediation of Istiklol city former uranium tailings. For this purpose, some experiences were adopted - Factory of Barren Ores tailing use for filling up the open pit where water with uranium content 3-5 mg/l is located. Factory of Barren Ores waste are passed through heap leaching and have some amount of uranium salts dissolved in water. Thus, we propose to dissolve uranium from Factory of Barren Ores wastes with uranium bearing water flowing out from gallery and filling up the open-pit by radioactive wastes. In so doing, uranium content flowing out from gallery will increase twice, and further, passing them through apricot's shell, as a sorbent, we will clean the water against radionuclides. Residue samples with uranium content 0,015% from Factory of Barren Ores and uranium bearing waters from gallery 1 with uranium content 0,0025 g/l were used for laboratory tests. After which, a slurry was prepared by means of residue mixing with water in ratio of solid and liquid phases (S:L) - 1:2 and 9,7 ml of sulfuric acid (Ρ=1,82) was added which corresponds consumption by H 2 SO 4 176,54 kg/t. For the first test, leaching was carried out during 4 hours at ph=1,6 at room temperature. For the second test, leaching was carried out at 60 d eg C a nd ph=1,6 during 4 hours. Slurry heating and mixing was carried out by means of magnetic mixer. The basic residue leaching indicators are provided in this article.

Ore microscopy applied to beneficiation

International Nuclear Information System (INIS)

Hagni, R.D.

1978-01-01

Ore microscopy can be an important adjunct to beneficiation, because it can be used not only to predict mill problems of undeveloped ore deposits but to identify the causes for the loss of minerals in the products of operating mines and mills. Mineral distribution among various mill products can be determined by examining polished sections prepared from samples obtained from each step of the beneficiation process. The degree of liberation of each mineral can be quantitatively determined for each mill product by counting locked vs. free particles. For many beneficiation problems, the preparation of a few polished sections of carefully selected mill products can yield useful information, which the mill dressing engineer can effectively use to alleviate those problems

Photodynamic effect of aluminium and zinc tetrasulfophthalocyanines on melanoma cancer cells

CSIR Research Space (South Africa)

Maduray, K

2010-06-01

Full Text Available Aluminium and zinc tetrasulfophthalocyanines were activated with a 672nm wavelength laser to investigate the photodynamic effects on melanoma cancer, dermal fibroblast and epidermal keratinocyte cells. Aluminium tetrasulfophthalocyanine was more...

X-ray radiometric separation of low-grade tin ores

Energy Technology Data Exchange (ETDEWEB)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-10-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

X-ray radiometric separation of low-grade tin ores

International Nuclear Information System (INIS)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-01-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

Isolation and identification of iron ore-solubilising fungus

Directory of Open Access Journals (Sweden)

Damase Khasa

2010-09-01

Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca₃(PO₄₂in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

Control of Rock Mechanics in Underground Ore Mining

Science.gov (United States)

Golik, V. I.; Efremenkov, A. B.

2017-07-01

Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

Economic evaluation of preconcentration of uranium ores

International Nuclear Information System (INIS)

1981-04-01

The economics of two options for the preconcentration of low-grade uranium ores prior to hydrochloric acid leaching were studied. The first option uses flotation followed by wet high-intensity magnetic separation. The second option omits the flotation step. In each case it was assumed that most of the pyrite in the ore would be recovered by froth flotation, dewatered, and roasted to produce sulphuric acid and a calcine suitable for acid leaching. Savings in operating costs from preconcentration are offset by the value of uranium losses. However, a capital saving of approximately 6 million dollars is indicated for each preconcentration option. As a result of the capital saving, preconcentration appears to be economically attractive when combined with hydrochloric acid leaching. There appears to be no economic advantage to preconcentration in combination with sulphuric acid leaching of the ore

Aluminium based adjuvants and their effects on mitochondria and lysosomes of phagocytosing cells.

Science.gov (United States)

Ohlsson, Lars; Exley, Christopher; Darabi, Anna; Sandén, Emma; Siesjö, Peter; Eriksson, Håkan

2013-11-01

Aluminium oxyhydroxide, Al(OH)3 is one of few compounds approved as an adjuvant in human vaccines. However, the mechanism behind its immune stimulating properties is still poorly understood. In vitro co-culture of an aluminium adjuvant and the human monocytic cell line THP-1 resulted in reduced cell proliferation. Inhibition occurred at concentrations of adjuvant several times lower than would be found at the injection site using a vaccine formulation containing an aluminium adjuvant. Based on evaluation of the mitochondrial membrane potential, THP-1 cells showed no mitochondrial rupture after co-culture with the aluminium adjuvant, instead an increase in mitochondrial activity was seen. The THP-1 cells are phagocytosing cells and after co-culture with the aluminium adjuvant the phagosomal pathway was obstructed. Primary or early phagosomes mature into phagolysosomes with an internal pH of 4.5 - 5 and carry a wide variety of hydrolysing enzymes. Co-culture with the aluminium adjuvant yielded a reduced level of acidic vesicles and cathepsin L activity, a proteolytic enzyme of the phagolysosomes, was almost completely inhibited. THP-1 cells are an appropriate in vitro model in order to investigate the mechanism behind the induction of a phagocytosing antigen presenting cell into an inflammatory cell by aluminium adjuvants. Much information will be gained by investigating the phagosomal pathway and what occurs inside the phagosomes and to elucidate the ultimate fate of phagocytosed aluminium particles. © 2013.

Numerical/experimental research on welded joints in aluminium truss girders

NARCIS (Netherlands)

van Hove, B.W.E.M.; Soetens, F.; Mazzolani, F.M.; Bellucci, F.; Faggiano, B.; Squillace, A.

2016-01-01

Welded joints in a 30 meter span aluminium truss girder were investigated numerically and experimentally. Since aluminium design rules for welded K-and N-joints in CHS truss girders were lacking the joints were checked using steel design rules. Calculations showed that the N-joints were governing

Dynamics of leaching a uniformly fissured ore body

International Nuclear Information System (INIS)

Ignatov, A.A.; Proskurin, S.A.

1987-01-01

Mathematical simulation was used to study the dynamics of mass transfer during the percolation of a reagent solution through a packing of coarse ore particles. The uniformly fissured ore body was represented by a cubic packing of spherical particles of constant radius, formed from a chemically inert silicate cement with a uniformly distributed soluble mineral component. The rate of percolation of the reagent through the packing was constant. The proposed model can be used to find the conditions for underground hydrodynamic leaching. The rate of non-catalytic solid-liquid reaction was deduced on the basis of both the kinetics of dissolution of the mineral component of the ore and the rate of diffusion of the dissolved substance

FY2017 status report: Model 9975 O-ring fixture long-term leak performance

Energy Technology Data Exchange (ETDEWEB)

Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-07-27

A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results

Moessbauer study of the chemical state of gold in gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

1986-01-01

Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

Numerical modelling of closed-cell aluminium foam under dynamic loading

Science.gov (United States)

Hazell, Paul; Kader, M. A.; Islam, M. A.; Escobedo, J. P.; Saadatfar, M.

2015-06-01

Closed-cell aluminium foams are extensively used in aerospace and automobile industries. The understanding of their behaviour under impact loading conditions is extremely important since impact problems are directly related to design of these engineering structures. This research investigates the response of a closed-cell aluminium foam (CYMAT) subjected to dynamic loading using the finite element software ABAQUS/explicit. The aim of this research is to numerically investigate the material and structural properties of closed-cell aluminium foam under impact loading conditions with interest in shock propagation and its effects on cell wall deformation. A μ-CT based 3D foam geometry is developed to simulate the local cell collapse behaviours. A number of numerical techniques are applied for modelling the crush behaviour of aluminium foam to obtain the more accurate results. The simulation results are compared with experimental data. Comparison of the results shows a good correlation between the experimental results and numerical predictions.

"INHIBITORY EFFECT OF ALUMINIUM ON KCL AND PHENYLEPHRINE INDUCED CONTRACTION IN ISOLATED RAT AORTA"

Directory of Open Access Journals (Sweden)

T. Mashhoodi

2004-10-01

Full Text Available It has been shown in some investigations that cardiovascular events are the main causes of death in hemodialysis patients. The exact etiology is unknown but some of the articles have reported a relation between aluminium ions in the dialysis solution and cardiovascular disorders. To determine the probable effect of aluminium on vasculature function, in vitro effects of aluminium ion on vasoconstriction induced by KCl (30 mM or phenylephrine (10 µM were investigated using isolated rat aorta. AlCl3 (1-4 mM decreased both KCl and phenylephrine induced contractions in a dose dependent manner (P<0.01. Complete inhibition of the contractions occurred using the higher doses of aluminium. Results of this study suggest that because of inhibitory effects of aluminium on vascular contractions, the probable cardiovascular dysfunction must be considered in aluminium intoxication.

Thermodynamic properties of uranium in gallium–aluminium based alloys

International Nuclear Information System (INIS)

Volkovich, V.A.; Maltsev, D.S.; Yamshchikov, L.F.; Chukin, A.V.; Smolenski, V.V.; Novoselova, A.V.; Osipenko, A.G.

2015-01-01

Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

Thermodynamic properties of uranium in gallium–aluminium based alloys

Energy Technology Data Exchange (ETDEWEB)

Volkovich, V.A., E-mail: v.a.volkovich@urfu.ru [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Maltsev, D.S.; Yamshchikov, L.F. [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Chukin, A.V. [Department of Theoretical Physics and Applied Mathematics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Smolenski, V.V.; Novoselova, A.V. [Institute of High-Temperature Electrochemistry UD RAS, Ekaterinburg, 620137 (Russian Federation); Osipenko, A.G. [JSC “State Scientific Centre - Research Institute of Atomic Reactors”, Dimitrovgrad, 433510 (Russian Federation)

2015-10-15

Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

Directory of Open Access Journals (Sweden)

SULTAN AHMED KHOSO

2017-10-01

Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

Comparison of the x-ray attenuation properties of breast calcifications, aluminium, hydroxyapatite and calcium oxalate.

Science.gov (United States)

Warren, L M; Mackenzie, A; Dance, D R; Young, K C

2013-04-07

Aluminium is often used as a substitute material for calcifications in phantom measurements in mammography. Additionally, calcium oxalate, hydroxyapatite and aluminium are used in simulation studies. This assumes that these materials have similar attenuation properties to calcification, and this assumption is examined in this work. Sliced mastectomy samples containing calcification were imaged at ×5 magnification using a digital specimen cabinet. Images of the individual calcifications were extracted, and the diameter and contrast of each calculated. The thicknesses of aluminium required to achieve the same contrast as each calcification when imaged under the same conditions were calculated using measurements of the contrast of aluminium foils. As hydroxyapatite and calcium oxalate are also used to simulate calcifications, the equivalent aluminium thicknesses of these materials were also calculated using tabulated attenuation coefficients. On average the equivalent aluminium thickness was 0.85 times the calcification diameter. For calcium oxalate and hydroxyapatite, the equivalent aluminium thicknesses were 1.01 and 2.19 times the thickness of these materials respectively. Aluminium and calcium oxalate are suitable substitute materials for calcifications. Hydroxyapatite is much more attenuating than the calcifications and aluminium. Using solid hydroxyapatite as a substitute for calcification of the same size would lead to excessive contrast in the mammographic image.

Different Approach to the Aluminium Oxide Topography Characterisation

International Nuclear Information System (INIS)

Poljacek, Sanja Mahovic; Gojo, Miroslav; Raos, Pero; Stoic, Antun

2007-01-01

Different surface topographic techniques are being widely used for quantitative measurements of typical industrial aluminium oxide surfaces. In this research, specific surface of aluminium oxide layer on the offset printing plate has been investigated by using measuring methods which have previously not been used for characterisation of such surfaces. By using two contact instruments and non-contact laser profilometer (LPM) 2D and 3D roughness parameters have been defined. SEM micrographs of the samples were made. Results have shown that aluminium oxide surfaces with the same average roughness value (Ra) and mean roughness depth (Rz) typically used in the printing plate surface characterisation, have dramatically different surface topographies. According to the type of instrument specific roughness parameters should be used for defining the printing plate surfaces. New surface roughness parameters were defined in order to insure detailed characterisation of the printing plates in graphic reproduction process

Quantitative electron probe microanalysis of borides in aluminium

International Nuclear Information System (INIS)

Karduck, P.; Schuerhoff, H.J.; Burchard, W.G.

1983-01-01

A procedure for the quantitative analysis of borides in aluminium was introduced. For this purpose the optimal apparative boundary conditions for the EPMA of boron were worked out. With these conditions a satisfactory peak to background ratio of 57 could be achieved for B-Kα-radiation. By application of this method the following conclusion should be drawn concerning the kind of nuclei during grain refinement of aluminium with titanium and boron: For grain refinement of aluminium with titanium and boron in the hypoperitectic region of the binary system Al-Ti TiB 2 -particles in clusters provide the high efficiency of refinement. This entails that the TiB 2 -particles already present in the master alloy remain inert in the melt. Hence, the good efficiency of refinement in this region cannot be attributed to the presence of particles like Al 3 Ti, AlB 2 or (Al, Ti) B 2 . (Author)

Developments of uranium and gold ores heap leaching technologies

International Nuclear Information System (INIS)

Tian Yuan; Guan Zibin; Gao Renxi

1998-01-01

The author reviews developments in heap leaching of uranium and gold ores at home and abroad, summarises condition of application. The author also presents problems having to be studied and settled urgently in heap leaching of uranium and gold ores in China

Aluminium - Cobalt-Pillared Clay for Dye Filtration Membrane

Science.gov (United States)

Darmawan, A.; Widiarsih

2018-04-01

The manufacture of membrane support from cobalt aluminium pillared clay has been conducted. This research was conducted by mixing a clay suspension with pillared solution prepared from the mixture of Co(NO3)2.6H2O and AlCl3.6H2O. The molar ratio between Al and Co was 75:25 and the ratio of [OH-]/[metal] was 2. The clay suspension was stirred for 24 hours at room temperature, filtered and dried. The dried clay was then calcined at 200°C, 300°C and 400°C with a ramp rate of 2°C/min. Aluminium-cobalt-pillared clay was then characterized by XRD and GSA and moulded become a membrane support for subsequent tests on dye filtration. The XRD analysis showed that basal spacing (d 001) value of aluminium cobalt was 19.49 Å, which was higher than the natural clay of 15.08Å however, the basal spacing decreased with increasing calcination temperature. The result of the GSA analysis showed that the pore diameter of the aluminium cobalt pillared clay membrane was almost the same as that of natural clay that were 34.5Å and 34.2Å, respectively. Nevertheless, the pillared clay has a more uniform pore size distribution. The results of methylene blue filtration measurements demonstrated that the membrane filter support could well which shown by a clear filtrate at all concentrations tested. The value of rejection and flux decreased with the increasing concentration of methylene blue. The values of dye rejection and water flux reached 99.89% and 5. 80 x 10-6 kg min-1, respectively but they decreased with increasing concentration of methylene blue. The results of this study indicates that the aluminium-pillared clay cobalt could be used as membrane materials especially for ultrafiltration.

Extraction of metals from ores by bacterial leaching: present status and future prospects

International Nuclear Information System (INIS)

Kelly, D.P.

1977-01-01

The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

Combined Corrosion and Wear of Aluminium Alloy 7075-T6

NARCIS (Netherlands)

Liu, Y.; Mol, J.M.C.; Janssen, G.C.A.M.

2016-01-01

The aluminium alloy 7075-T6 is widely used in engineering. In some applications, like slurry transport, corrosion and abrasion occur simultaneously, resulting in early material failure. In the present work, we investigated the combined effect of corrosion and wear on the aluminium alloy 7075-T6. We

Novel Binders and Methods for Agglomeration of Ore

Energy Technology Data Exchange (ETDEWEB)

S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

2006-03-31

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

Energy Technology Data Exchange (ETDEWEB)

S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

2004-04-01

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

Novel Binders and Methods for Agglomeration of Ore

Energy Technology Data Exchange (ETDEWEB)

S. K. Kawatra; T. C. Eisele; J. A. Gurtler; K. Lewandowski

2005-09-30

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

Grain Refinement of Commercial EC Grade 1070 Aluminium Alloy for Electrical Application

OpenAIRE

Hassanabadi, Massoud

2015-01-01

The aluminium alloys for electrical conductivity applications are generally not grain refinedsince the addition of grain refiners drops the electrical conductivity by introducing impuritiesinto the melt. Non-grain refined aluminium may lead to bar fracture and cracks during themetalworking process. The present study focuses to find an optimum balance between the grain refiner addition andthe electrical conductivity of commercial EC grade 1070 aluminium alloy for electricalapplication. In orde...

Development of microstructure during sintering and aluminium exposure of titanium diboride ceramics

Energy Technology Data Exchange (ETDEWEB)

Pettersen, Gunnar

1997-12-31

In the production of aluminium, much less energy need be consumed if an inert, wetted cathode is present in the electrolysis cell. Titanium diboride, TiB{sub 2}, is easily wetted and does not readily dissolve in liquid aluminium, but it degrades, probably because aluminium penetrates into it during electrolysis. This degradation is linked to impurities present in the TiB{sub 2} after sintering. This thesis studies the sintering process and how aluminium penetrates into the material. High-purity, high-density TiB{sub 2} compacts were made by hot pressing at 50 MPa in an argon atmosphere at 1790-1960 {sup o}C. Samples were made with different impurity additions. These samples were exposed to liquid aluminium at 980 {sup o}C for 24 hours. All samples were penetrated, but the amount and appearance depended on the sintering aid used. Unlike the other samples, pure TiB{sub 2} was easily penetrated by metallic aluminium because of the open porosity and microcracks of this material. Grain boundary penetration was common among the samples. Differences in penetration behaviour between grain boundaries are probably due to differences in grain boundary energy. But no relation to segregants or boundary misorientation was found. The orientation of grain boundary planes and de-wetting of thin films upon cooling may explain the observed microstructure development. The samples sintered with Ti addition suffered extensive penetration despite their high densities. The grain boundaries of these samples became faceted and contained thicker films of metallic aluminium, presumably because of increased solubility due to iron segregations. All secondary phases present in the grain junctions after sintering, except from the B{sub 4}C phase, reacted with the penetrated aluminium. This did not cause swelling and cracking, as has been suggested by other authors. 101 refs., 48 figs., 7 tabs.

Effects of Ore dust pollution on the physical and chemical features ...

African Journals Online (AJOL)

Effects of wind-blown iron and manganese ore dust on the upper part of a sandy beach have been investigated. The fine ore dust was found to reduce the porosity and permeability of the sand by clogging the interstices. The presence of ore dust also greatly increased the rate of heating and cooling of beach sand. Further ...

The Bairendaba silver polymetallic deposit in Inner Mongolia, China: characteristics of ore-forming fluid and genetic type of ore deposit

Science.gov (United States)

Wang, Ying; Xie, Yuling; Wu, Haoran

2018-02-01

Bairendaba silver-polymetallic deposit is located in the middle south of the Xing Meng orogenic belt, and in the silver-polymetallic metallogenic belt on the west slope of the southern of Great Xing’an Range. Based on studying of the fluid inclusion, we discuss the characteristics of ore-forming fluid and the metallic genesis of the Bairendaba silver-polymetallic deposit. By means of the analysis of the fluid inclusions, homogenization temperature, salinity and composition were studied in quartz and fluorite. The result is as the follows: with homogenization temperatures of fluid inclusions in quartz veins being 196∼312 °C, the average 244.52 °C, and fluid salinity 2.90∼9.08 wt%NaCl; with homogenization temperatures of fluid inclusions in fluorite being 127∼306 °C, the average 196.92 °C, and fluid salinity 2.90∼9.34 wt% NaCl. The ore-forming fluid is mainly composed of water and the gas. The results of laser Raman analysis show that the gas phase is mainly CH4. It shows that the ore-forming fluid is characterized by medium-low temperature and low-salinity system. The temperature of ore-forming fluid is from high to low, and the salinity from high to low, and the meteoric water or metamorphic water is added during deposit. According to the geological characteristics of the mining area, it is considered that the genetic type of the ore deposit should be the fault-controlled and the medium-low temperature hydrothermal deposit related to magmatic hydrothermal activities.

Effect of Microbial inoculation in combating the aluminium toxicity effect on growth of Zea mays.

Science.gov (United States)

Arora, P; Singh, G; Tiwari, A

2017-07-31

The present study is aimed at improving the aluminium tolerance in maize crop employing the potential of microbial inoculants in conferring resistance to these toxicities via production of certain chelating compounds like siderophores, exopolysachharides and organic acids. Acid soils have now-a-days become one of the key factors for limiting growth of many agriculturally important crops. Aluminium  is one of the major elements present in acid soils and is mainly responsible for toxicity in the soil. This aluminium is rapidly soluble in soil water and hence absorbed by plant roots under conditions where soil pH is below 5. This toxicity leads to severe root growth inhibition, thereby limiting the production of maize crops. It was observed that use of microbial inoculums can be helpful in elimination of these toxic compounds and prevent the inhibition of root growth . It was found that the soils contaminated with aluminium toxicity decreased the root length of maize plant significantly by 65% but Bacillus and Burkholderia inoculation increased this root length significantly by 1.4- folds and 2- folds respectively thereby combating the effect of aluminium toxicity. Aluminium concentration was found maximum in roots of plants which were grown under aluminium stress condition. But this aluminium accumulation decreased ̴ 2-folds when Burkholderia was used as seed inoculants under aluminium stress conditions. Also, at 60mM aluminium accumulation, phosphorus solubilisation in roots was found to be increased upto 30% on Burkholderia inoculation. However, Bacillus inoculation didn't show any significant difference in either of the case. Thus, the inoculation of seeds with Burkholderia isolates could prove to be a boon in sequestering aluminium toxicity in Zea mays.

Effective Processing of the Iron Ores

Science.gov (United States)

Kuskov, Vadim; Kuskova, Yana; Udovitsky, Vladimir

2017-11-01

Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats): comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Effective Processing of the Iron Ores

Directory of Open Access Journals (Sweden)

Kuskov Vadim

2017-01-01

Full Text Available Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats: comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Risk minimisation of FGD gypsum leachates by incorporation of aluminium sulphate

Energy Technology Data Exchange (ETDEWEB)

Alvarez-Ayuso, E. [Department of Environmental Geology, Institute of Earth Sciences ' Jaume Almera' (CSIC), C/ Lluis Sole i Sabaris, s/n, 08028 Barcelona (Spain); Department of Environmental Geochemistry, IRNASA, CSIC, Apto. 257, 37071 Salamanca (Spain)], E-mail: ealvarez@ija.csic.es; Querol, X. [Department of Environmental Geology, Institute of Earth Sciences ' Jaume Almera' (CSIC), C/ Lluis Sole i Sabaris, s/n, 08028 Barcelona (Spain); Ballesteros, J.C.; Gimenez, A. [Endesa Generacion, S.A., C/ Ribera de Loira, 60, 28042 Madrid (Spain)

2008-11-15

The incorporation of aluminium sulphate to (flue gas desulphurisation) FGD gypsum before its disposal was investigated as a way to minimise the risk supposed by the high fluoride content of its leachates. Using a bath method the kinetic and equilibrium processes of fluoride removal by aluminium sulphate were studied at fluoride/aluminium molar concentration (F/Al) ratios in the range 1.75 10{sup -2}-1.75 under the pH conditions (about 6.5) of FGD gypsum leachates. It was found that fluoride removal was a very fast process at any of the (F/Al) ratios subject of study, with equilibrium attained within the first 15 min of interaction. High decreases in solution fluoride concentrations (50-80%) were found at the equilibrium state. The use of aluminium sulphate in the stabilization of FGD gypsum proved to greatly decrease its fluoride leachable content (in the range 20-90% for aluminium sulphate doses of 0.1-5%, as determined by the European standard EN 12457-4). Such fluoride leaching minimisation assures the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC on waste disposal. Furthermore, as derived from column leaching studies, the proposed stabilization system showed to be highly effective in simulated conditions of disposal, displaying fluoride leaching reduction values about 55 and 80% for aluminium sulphate added amounts of 1 and 2%, respectively.

Chapter 1. General information about uranium. 1.3. Uranium ores

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

2012-01-01

The uranium ores were described. It was found that uranium ores and natural mineral formations containing uranium and its compounds, can be found in concentrations that are technically possible for industrial utilization and which are economically profitable. It was defined that oxidation levels of uranium minerals have an impact on their reprocessing technology and behavior in hydrometallurgical re partition. It was found that the chemical composition of ores has a decisive importance during selection of their reprocessing method.

Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting

Directory of Open Access Journals (Sweden)

Iban Vicario

2016-01-01

Full Text Available Nowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.

Adsorption of lithium ion to amorphous hydrous aluminium oxide

International Nuclear Information System (INIS)

Wada, Hideo; Kitamura, Takao; Fujii, Ayako; Katoh, Shunsaku

1982-01-01

Adsorption process of lithium ion to amorphous hydrous aluminium oxide (a-HAO) was investigated by pH titration method with lithium chloride-lithium hydroxide mixed solution and X-ray diffraction analysis of a-HAO after pH titration. In the pH titration, the addition of hydroxide ion in amount from 0 to 4.0 mmol.g -1 gave no change to the pH of the solution and caused adsorption of lithium ion equivalent in amount to added hydroxide ion. X-ray diffraction analysis showed the formation of lithium hydrogenaluminate LiH (AlO 2 ) 2 .5H 2 O (LHA) in the a-HAO after pH titration. These results showed that adsorption of lithium ion by a-HAO was related to a reaction which consumed hydroxide ion and formed LHA. In order to elucidate detail process of the reaction, changes of pH, aluminium concentration and lithium concentration of the solution, respectively with time, were determined. The pH of the solution decreased in two stages. At the first stage of the pH decrease, the aluminium concentration increased whereas the lithium concentration did not change. At the second stage, the lithium concentration decreased together with the decrease of the aluminium concentration. It was inferred that adsorption of lithium ion proceeded through dissolution of a-HAO and precipitation of LHA. Theoretical adsorption capacity calculated from the above formula for LHA and aluminium content in a-HAO was 4.7 mmol.g -1 and agreed fairly well with observed value 4.0 mmol.g -1 . (author)

Utilisation of iron ore tailings as aggregates in concrete

Directory of Open Access Journals (Sweden)

Francis Atta Kuranchie

2015-12-01

Full Text Available Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

Coprecipitation of aluminium with hydroxides of tetra-, penta- and hexavalent actinides

International Nuclear Information System (INIS)

Yusov, A.B.; Budantseva, N.A.; Anan'ev, A.V.; Fedoseev, A.M.

2000-01-01

By the methods of IR spectroscopy and powder x-ray diffractometry precipitates formed in alkaline medium by actinide (4, 5, 6) in the presence of aluminium are studied. It is shown that in studied conditions formation of actinide aluminates not occurs. In the same time in the process of precipitation interaction of aluminium hydroxocomplexes with U(6) and Th(4) ions probably takes place. Hypothesis is expressed that possibility of aluminium hydroxocomplexes interaction with actinides in different oxidation state is depended on peculiarities of hydrolytic behaviour of the lasts [ru

A study on the role of diboride in the heterogeneous nucleation of aluminium

International Nuclear Information System (INIS)

Suarez, O. M.

2004-01-01

The intangible role of titanium and aluminium diboride in the nucleation of aluminium was re-examined. Two different techniques, complemented with scanning electron microscopy, allowed determining the stability of the diboride in the presence of titanium tri aluminides and liquid aluminium phases. Through rapid scintillated quenching the high temperature diboride were retained and studied. Then, in a diffusion couple, the reactivity of such diboride was tested in contact with pure titanium tri aluminide. It is proposed that a ternary diboride acts as the main catalytic particle in the crystallization of aluminium alloys with refined grains. (Author) 27 refs

Study of the electronic structure of pure aluminium, aluminium oxide and nitride by spectroscopy of electrons excited under electronic and photonic bombardment (X and UV)

International Nuclear Information System (INIS)

Gautier-Soyer, Martine

1985-01-01

This research thesis reports the use of electron spectroscopy with electrons excited under electronic or photonic (X or UV) bombardment for the study of electronic state density of aluminium, aluminium oxide (Al 2 O 3 ) and aluminium nitride (AlN). The objective is to get an insight into phenomena related to technological problems of adherence, wear, lubrication, corrosion or breakdown met in metals, insulators and semiconductors. The author highlighted the presence of occupied surface states on Al(111) and Al(100), and electronic levels localised in the forbidden band of Al 2 O 3 and AlN, induced by structural defects which promote surface reactivity [fr

Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

Science.gov (United States)

Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

2015-04-01

India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

Effect of aluminium particles on mechanical and morphological properties of epoxy nanocomposites

Directory of Open Access Journals (Sweden)

Bello Sefiu A.

2017-01-01

Full Text Available Bumper is a front or rear part of automobiles. It is designed and shaped to be impact absorbing and protecting automobiles from damage in low impact collisions. Initially, they were made from heavy steels, increasing the weight of automobiles and fuel consumption. Also, high impacts of steel bumpers on pedestrians during accidental collision cause fatalities and or disabilities. An effort to enhance fuel efficiency, safety, freedom of design and shape detailing, heavy alloys for automobile applications are now being replaced with polymeric composites. Aluminium micro particles and nanoparticles were prepared from aluminium cans through sand casting, lathe machine spinning, and ball milling techniques. Both types of aluminium particles were incorporated into a mixture of diglycidyl ether of bisphenol A (DGEBA, epoxy resin cured with amine base hardener (ABH. Phases of the epoxy polymer and composites were identified using Xray Diffraction (XRD. Spatial arrangement of the phases within the matrix and their elemental composition were examined using Scanning Electron Microscope with attached energy dispersive X-ray spectroscopy (SEM/EDX. Tensile, impact and micro hardness tests were conducted on the prepared epoxy/aluminium composites. Results of the XRD showed the presence of aluminium compounds/phases due to chemical reactions between aluminium particles and DGEBA/ABH system. SEM confirmed a homogeneous distribution of the phases within the epoxy matrix, and that there is a strong adhesion between the epoxy matrix and aluminium particles. Correlation between the mechanical properties of the prepared nanocomposite and the procured bumper materials exhibited a fair suitability of the prepared nanocomposites for automobile applications.

Flotation of uranium from uranium ores in Canada. Part 1

International Nuclear Information System (INIS)

Muthuswami, S.V.; Vigayan, S.; Woods, D.R.; Banerjee, S.

1983-01-01

About 150 flotation tests were done on Elliot Lake ore with 15 reagents as collectors in order to screen and choose an attractive collector for uranium flotation. Several variables were studied including pH, conditioning time and mode of collector addition. The tests were done in a Denver or Agitair subaeration cell. The particle size of the ore was kept at 85% below -325 mesh. Three reagents (Kelex 00, TOPO, and cupferron) were identified as having the most promise. The best results were obtained with cupferron, where 93-95% of the uranium was recovered in 25-30% of the mass of original ore. Radium in the tails varied between 5 and 30 pCi/g depending on the mass of uranium floated. Radium was recovered in proportion to uranium in the tests done at neutral pH. The preconcentration results obtained by flotation alone were comparable to those obtained using pyrite flotation and wet high-intensity magnetic separation of uranium. The consumption of cupferron was 4 kg/Mg ore for each flotation stage. This was 10-15 times larger than the collector usage in conventional oxide flotation. This scheme did not require other reagents as depressants, activators or modifiers. Reproducibility was good and similar recoveries were obtained with fresh or old ores, and with distilled or mine water. The selectivity of cupferron for uranium in the ore studied was outstanding

Comparative performance of aluminium copper and iron solar stills

International Nuclear Information System (INIS)

Dioha, I.J.; Nwagbo, E.E.; Gulma, N.A.

1990-12-01

Three different metal sheets have been used in the fabrication of three different single sloping solar stills of the same surface geometry. The metals were galvanized iron, aluminium and copper. This paper presents the performance of the different stills operating under the same environmental conditions. The observed distillate yields was greatest for copper, then aluminium and lastly, iron still. The differences in the yields is attributed to the differences in the thermal conductivities of the metals. The equivalent local costs for the fabrication of the copper, aluminium and iron stills are respectively $160, $95 and $60. Taking the long run costs into consideration, the copper still is preferred because of its availability, durability, weldability and relatively higher conductivity of 380Wm -1 K -1 value. (author). 9 refs, 2 figs, 2 tabs

Aluminium and Alzheimer's disease: the science that describes the link

National Research Council Canada - National Science Library

Exley, Christopher

2001-01-01

... that has been encircled is the gene for the amyloid precursor protein. (Thanks to Walter Lukiw for supplying this information.) Aluminium and Alzheimer's Disease: The Science that Describes the LinkAluminium and Alzheimer's Disease The Science that Describes the Link Edited by Christopher Exley Birchall Centre for Inorganic Chemistry and Materials Scienc...

Commercial development of a new process of uraniferous ore sintering by pelletizing before dump leaching (wet process) application to a very clayey ore of Nord-Aquitaine

International Nuclear Information System (INIS)

Videau, G.; Roche, M.

1990-01-01

Much of the French uranium ore contains clay of sedimentary origin or derived from the alteration of rocks of the granite type. During a dump leaching operation by a wet process, these clays reduce the percolation rates and sometimes the percolation rates are so low that the very essence of the dump leaching operation can be called in question. This problem arises particularly for the treatment of the ore of Nord-Aquitaine. The results of tests, carried out at the SEPA in Bessines, have shown that after pelletizing clayey ores with sodium silicate in the presence of sulphuric acid for the polymerization of the silicate, the percolation rates were much increased. This new method was successfully applied, from a laboratory column to a pilot dump of 500 tonnes for the very clayey ore of Nord-Aquitaine. This ore of low grade (approx. 1000 ppm of U) seems to be difficult to upgrade by any other method of treatment in the present economic context [fr

Fluid evolution and ore genesis of the Dalingshang deposit, Dahutang W-Cu ore field, northern Jiangxi Province, South China

Science.gov (United States)

Peng, Ning-Jun; Jiang, Shao-Yong; Xiong, Suo-Fei; Pi, Dao-Hui

2018-02-01

The Dalingshang W-Cu deposit is located in the North section of the Dahutang ore field, northern Jiangxi Province, South China. Vein- and breccia-style tungsten-copper mineralization is genetically associated with Mesozoic S-type granitic rocks. Infrared and conventional microthermometric studies of both gangue and ore minerals show that the homogenization temperatures for primary fluid inclusions in wolframite ( 340 °C) are similar to those in scheelite ( 330 °C), but about 40 °C higher than those of apatite ( 300 °C) and generally 70 °C higher than those in coexisting quartz ( 270 °C). Laser Raman analysis identifies CH4 and N2 without CO2 in fluid inclusions in scheelite and coexisting quartz, while fluid inclusions in quartz of the sulfide stage have variable CO2 content. The ore-forming fluids overall are characterized by high- to medium-temperature, low-salinity, CH4, N2, and/or CO2-bearing aqueous fluids. Chalcopyrite, muscovite, and sphalerite are the most abundant solids recognized in fluid inclusions from different ores. The H-O-S-Pb isotope compositions favor a dominantly magmatic origin for ores and fluids, while some depleted δ34S values (- 14.4 to - 0.9‰) of sulfides from the sulfide stage are most likely produced by an increase of oxygen fugacity, possibly caused by inflow of oxidized meteoric waters. The microthermometric data also indicate that a simple cooling process formed early scheelite and wolframite. However, increasing involvement of meteoric waters and fluid mixing may trigger a successive deposition of base metal sulfides. Fluid-rock interaction was critical for scheelite mineralization as indicated by in-situ LA-ICP-MS analysis of trace elements in scheelite.

Activation Analysis of Aluminium

Energy Technology Data Exchange (ETDEWEB)

Brune, Dag

1961-01-15

An analysis of pure aluminium alloyed with magnesium was per- formed by means of gamma spectrometry , Chemical separations were not employed. The isotopes to be determined were obtained in conditions of optimum activity by suitably choosing the time of irradiation and decay. The following elements were detected and measured quantitatively: Iron, zinc, copper, gallium, manganese, chromium, scandium and hafnium.

Technological studies on the Manisa-Koprubasi uranium ores of Turkey

International Nuclear Information System (INIS)

Sagdik, U.

1980-01-01

At the end of the laboratory and pilot plant scale technological experiments, three main types of ore have been classified: (i) Kasar type: The ores consist of secondary uranium mineralization (autunite, meta-autunite and torbenite) in loosely consolidated sands, gravels and clays of Neogene Age. Heap leaching has been carried out on 100 and 1000 t ore samples (0.05% U 3 O 8 ) under economical conditions, such as 20 to 40 kg of H 2 SO 4 per tonne of ore at ambient temperature; original size -20 cm, solid/liquid ratio of 10, 20 days, and 90% recovery of uranium has been reached. The uraniferous solutions (1 to 2 g of U 3 O 8 per litre) obtained from the heap leaching operations were purified in a solvent extraction unit with a capacity of 100 ltr/h by using an Alamine 336-kerosene-decanol solution. The uranium in the purified and concentrated solutions (15 g of U 3 O 8 per litre) was then precipitated as a yellow cake with 65 to 75% U 3 O 8 content by means of magnesia milk. (ii) Tasharman type: No specific uranium mineral has been detected in the mineralogical determination, although uranium is disseminated in phosphate minerals as dahllite and apatite. Uranium in the ore has been leached under rather uneconomical conditions; 100 kg of H 2 SO 4 per tonne of ore, particle size -1 cm, 25 0 C, 30 days. In the SX-treatment of pregnant solutions phosphate ions, higher acidity than pH 1, and compounds formed as a chemical precipitation, hindered the SX-recoveries. In such cases, the addition of acid, dilution of pregnant solutions, membrane filtration, or 40 0 C temperature have been applied to decrease the uranium loss in the raffinate. (iii) Carbonate type: Even if alkaline leaching at 65 0 C, or leaching with 400 kg of H 2 SO 4 per tonne of ore, was carried out on -200 mesh ore samples, no acceptable uranium recoveries were obtained

Diagnostics of ytterbium/aluminium laser plasmas

International Nuclear Information System (INIS)

Bailey, J.; Lee, R.W.; Landen, O.L.; Kilkenny, J.D.; Lewis, C.L.; Busquet, M.

1986-11-01

Microdot spectroscopy was used to study the x-ray emission from laser-produced plasmas consisting of 10% ytterbium, 90% aluminium. Spectra were recorded with a space-resolving flat crystal (PET) mini-spectrometer in the 4.0-8.0 A range. The Janus research laser at LLNL irradiated the targets with green (0.53 μm) light in a 1 nsec pulse. The power density was varied between 4x10 13 and 3x10 14 W/cm 2 . The plasma electron density and temperature were determined from the aluminium XI, XII and XIII line emission. By examining correlations between changes in the plasma conditions with changes in the ytterbium spectra, we will determine the potential for using ytterbium line emission as a plasma diagnostic

Geochemistry and geochronology of ore-bearing and barren intrusions in the Luanchuan ore fields of East Qinling metallogenic belt, China: Diverse tectonic evolution and implications for mineral exploration

Science.gov (United States)

Xue, Fei; Wang, Gongwen; Santosh, M.; Yang, Fan; Shen, Zhiwei; Kong, Liang; Guo, Nana; Zhang, Xuhuang; Jia, Wenjuan

2018-05-01

The Luanchuan ore fields form part of the East Qinling metallogenic belt in central China. In this study, we compare two ore-bearing intrusions, the Shibaogou granitic pluton (SBG) and the Zhongyuku granitic pluton (ZYK), with the ore-barren Laojunshan intrusion (LJS) from the Luanchuan ore field. Geochemically, all the three intrusions are characterized by high-Si, high-K, and alkalis, together with moderate-ASI, exhibiting I-type granite features. The rocks, especially the ore-related plutons also show enrichment in LREEs. Mineral chemistry of biotite from the intrusions exhibits similar features of high Si and Mg, and low Al and Fe. Zircon grains from the ZYK intrusion yielded a U-Pb age of 149.6 ± 2.4 Ma. The zircon grains show εHf (t) values and two stage model ages (TDM2) in the range of -16.8 to -19.7 and 1998-2156 Ma respectively. The biotite composition and Hf isotopic data indicate that the magma was derived by re-melting of deep crustal material with minor input of mantle components. We evaluate the results to understand the physico-chemical conditions, petrogenesis, and tectonic setting, and their implications for mineral exploration. The ore-bearing plutons show wide ranges of temperature and oxygen fugacity, favoring Mo-W mineralization. In addition, estimates on pressure and depth of emplacement suggest that lower solidification pressure in a decompressional setting contributed to the evolution of magmatic hydrothermal deposits. Our data suggest that the ZYK has the highest potential for Mo-W mineralization. The ore-bearing plutons of ZYK and SBG were formed in a transitional tectonic setting from compression to extension, with the large-scale metallogeny triggered by slab melts at ca. 145 Ma. However, the ore-barren LJS batholith formed in an extension-related geodynamic setting at ∼115 Ma. Our study shows that different tectonic settings and consequent physico-chemical conditions dictated the ore potential of the intrusions in the Luanchuan ore

Corrosion of research reactor aluminium clad spent fuel in water

International Nuclear Information System (INIS)

2009-12-01

A large variety of research reactor spent fuel with different fuel meats, different geometries and different enrichments in 235 U are presently stored underwater in basins located around the world. More than 90% of these fuels are clad in aluminium or aluminium based alloys that are notoriously susceptible to corrosion in water of less than optimum quality. Some fuel is stored in the reactor pools themselves, some in auxiliary pools (or basins) close to the reactor and some stored at away-from-reactor pools. Since the early 1990s, when corrosion induced degradation of the fuel cladding was observed in many of the pools, corrosion of research reactor aluminium clad spent nuclear fuel stored in light water filled basins has become a major concern, and programmes were implemented at the sites to improve fuel storage conditions. The IAEA has since then established a number of programmatic activities to address corrosion of research reactor aluminium clad spent nuclear fuel in water. Of special relevance was the Coordinated Research Project (CRP) on Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water (Phase I) initiated in 1996, whose results were published in IAEA Technical Reports Series No. 418. At the end of this CRP it was considered necessary that a continuation of the CRP should concentrate on fuel storage basins that had demonstrated significant corrosion problems and would therefore provide additional insight into the fundamentals of localized corrosion of aluminium. As a consequence, the IAEA started a new CRP entitled Corrosion of Research Reactor Aluminium Clad Spent Fuel in Water (Phase II), to carry out more comprehensive research in some specific areas of corrosion of aluminium clad spent nuclear fuel in water. In addition to this CRP, one of the activities under IAEA's Technical Cooperation Regional Project for Latin America Management of Spent Fuel from Research Reactors (2001-2006) was corrosion monitoring and surveillance of research

Converting the Key Lake mill process for McArthur River ore

Energy Technology Data Exchange (ETDEWEB)

Rodgers, C. [McArthur River Operation, Cameco Corporation, Saskatoon, Saskatchewan (Canada)

2000-07-01

The Key Lake mill was commissioned in 1983 to process the two Key Lake ore deposits. With the depletion of these ore bodies in 1999, the plant was converted to mill the exceptionally rich McArthur River deposit located seventy eight kilometers northeast of the Key Lake mine site. This paper describes in detail the Key Lake milling process. The mill consists of a grinding circuit, a leach/counter current decantation circuit, a solvent extraction circuit, a yellowcake precipitation/calciner circuit, an ammonium sulphate crystallization circuit, and a waste treatment circuit. The paper also describes process changes to handle McArthur River ore, including the ore receiving station. (author)

A note on the behind armour effects from perforated alumina/aluminium targets

OpenAIRE

Hazell, P. J.; Fellows, N. A.; Hetherington, J. G.

1998-01-01

A thin, ceramic-faced armour, separated from a thick metal block, has been subjected to high-velocity impact by a 6.35 mm diameter steel sphere. Experimental work was carried out which compared firings into ceramic-faced aluminium armour, separated from thick aluminium witness blocks, with firings into the thick aluminium blocks alone. The depth of penetration and the area of damage were measured and an estimated percentage weight saving due to the inclusion of the ceramic-f...

Corrosion behaviour of nanometre sized cerium oxide and titanium oxide incorporated aluminium in NaCl solution

International Nuclear Information System (INIS)

Ashraf, P. Muhamed; Edwin, Leela

2013-01-01

Highlights: ► Corrosion resistant aluminium incorporated with nano oxides of cerium and titanium. ► 0.2% nano CeO 2 and 0.05% nano TiO 2 showed increased corrosion resistance. ► Nano TiO 2 concentration influenced the optimum performance of the material. ► Comparison of Micro and nano CeO 2 and TiO 2 aluminium showed the latter is best. - Abstract: The study highlights the development of an aluminium matrix composite by incorporating mixture of nanometre sized cerium oxide and titanium oxide in pure aluminium and its corrosion resistance in marine environment. The mixed nanometre sized oxides incorporated aluminium exhibited improved microstructure and excellent corrosion resistance. Corrosion resistance depends on the concentration of nanometre sized titanium oxide. Electrochemical characteristics improved several folds in nanometre sized mixed oxides incorporated aluminium than micrometre sized oxides incorporated aluminium.

Purity and surface roughness of vacuum deposited aluminium films

Energy Technology Data Exchange (ETDEWEB)

Dhere, N G; Arsenio, T P [Instituto Militar de Engenharia, Rio de Janeiro (Brazil); Patnaik, B K [Pontificia Universidade Catolica do Rio de Janeiro (Brazil). Instituto de Fisica; Assuncao, F C.R.; de Souza, A M [Pontificia Universidade Catolica do Rio de Janeiro (Brazil). Departamento de Ciencia dos Materiais e Metalurgia

1975-04-01

The authors studied the purity, surface roughness and grain size of vacuum-deposited aluminium films, using an intermetallic crucible and a continuous feed of pure aluminium wire. The grain size and roughness were studied by electron difraction, X-ray diffraction and the scanning electron microscope. Purity was determined by X-ray fluorescence produced by proton bombardment in the Van de Graaff accelerator and by X-ray and optical emission spectrometry.

Methods for the estimation of uranium ore reserves

International Nuclear Information System (INIS)

1985-01-01

The Manual is designed mainly to provide assistance in uranium ore reserve estimation methods to mining engineers and geologists with limited experience in estimating reserves, especially to those working in developing countries. This Manual deals with the general principles of evaluation of metalliferous deposits but also takes into account the radioactivity of uranium ores. The methods presented have been generally accepted in the international uranium industry

On the anodic aluminium oxide refractive index of nanoporous templates

International Nuclear Information System (INIS)

Hierro-Rodriguez, A; Rocha-Rodrigues, P; Araujo, J P; Valdés-Bango, F; Alameda, J M; Teixeira, J M; Jorge, P A S; Santos, J L; Guerreiro, A

2015-01-01

In the present study, we have determined the intrinsic refractive index of anodic aluminium oxide, which is originated by the formation of nanoporous alumina templates. Different templates have been fabricated by the conventional two-step anodization procedure in oxalic acid. Their porosities were modified by chemical wet etching allowing the tuning of their effective refractive indexes (air-filled nanopores  +  anodic aluminium oxide). By standard spectroscopic light transmission measurements, the effective refractive index for each different template was extracted in the VIS–NIR region. The determination of the intrinsic anodic aluminium oxide refractive index was performed by using the Maxwell–Garnett homogenization theory. The results are coincident for all the fabricated samples. The obtained refractive index (∼1.55) is quite lower (∼22%) than the commonly used Al 2 O 3 handbook value (∼1.75), showing that the amorphous nature of the anodic oxide structure strongly conditions its optical properties. This difference is critical for the correct design and modeling of optical plasmonic metamaterials based on anodic aluminium oxide nanoporous templates. (paper)

ADC3 YANG DIBUAT DENGAN PELEBURAN ULANG ALUMINIUM BEKAS SEBAGAI BAHAN PROPELER KAPAL KAYU

Directory of Open Access Journals (Sweden)

Suyanto Suyanto

2016-11-01

Full Text Available Saat ini pembuatan propeler aluminium pada industri kecil banyak memanfaatkan bahan dasar aluminium bekas. Namun produk yang dihasilkan belum memenuhi spesifikasi standar material. Penelitian dilakukan dengan menggunakan bahan dasar aluminium siku bekas dan aluminium kampas bekas. Variasi penambahan TiB sebagai grain refiner dilakukan pada saat peleburan. Perhitungan dengan simulasi Excel dilakukan untuk memperkirakan komposisi hasil pengecoran yang sesuai. Pengecoran ulang menghasilkan produk dengan tingkat porositas 3,3 % sampai 5,9 %. Penggunaan cetakan pasir ikut berperan dalam timbulnya porositas. Penambahan TiB sebanyak 0,5% ke ADC3 berpengaruh pada penurunan ukuran butir hingga 50%, peningkatan kekerasan hingga 23%, peningkatan kekuatan tarik hingga 11%, serta penurunan keuletan hingga 20%. Kata kunci: ADC3, pengecoran ulang aluminium, propeler.

Advances and Opportunities in Ore Mineralogy

Directory of Open Access Journals (Sweden)

Nigel J. Cook

2017-11-01

Full Text Available The study of ore minerals is rapidly transforming due to an explosion of new micro- and nano-analytical technologies. These advanced microbeam techniques can expose the physical and chemical character of ore minerals at ever-better spatial resolution and analytical precision. The insights that can be obtained from ten of today’s most important, or emerging, techniques and methodologies are reviewed: laser-ablation inductively-coupled plasma mass spectrometry; focussed ion beam-scanning electron microscopy; high-angle annular dark field scanning transmission electron microscopy; electron back-scatter diffraction; synchrotron X-ray fluorescence mapping; automated mineral analysis (Quantitative Evaluation of Mineralogy via Scanning Electron Microscopy and Mineral Liberation Analysis; nanoscale secondary ion mass spectrometry; atom probe tomography; radioisotope geochronology using ore minerals; and, non-traditional stable isotopes. Many of these technical advances cut across conceptual boundaries between mineralogy and geochemistry and require an in-depth knowledge of the material that is being analysed. These technological advances are accompanied by changing approaches to ore mineralogy: the increased focus on trace element distributions; the challenges offered by nanoscale characterisation; and the recognition of the critical petrogenetic information in gangue minerals, and, thus the need to for a holistic approach to the characterization of mineral assemblages. Using original examples, with an emphasis on iron oxide-copper-gold deposits, we show how increased analytical capabilities, particularly imaging and chemical mapping at the nanoscale, offer the potential to resolve outstanding questions in ore mineralogy. Broad regional or deposit-scale genetic models can be validated or refuted by careful analysis at the smallest scales of observation. As the volume of information at different scales of observation expands, the level of complexity

A reliability based stress-life evaluation of aluminium-graphite particulate composites

International Nuclear Information System (INIS)

Achutha, M.V.; Sridhara, B.K.; Abdul Budan, D.

2008-01-01

Fatigue tests were conducted on sand cast aluminium-graphite composite specimens on Rotating Beam Fatigue Testing Machine with three different stress levels. Aluminium-graphite (LM 25-5% graphite) composite was processed by closed mould sand casting method. Three-stress level fatigue test program was planned for carrying out fatigue experiments. Three different stress levels selected for fatigue experiments were a fraction of ultimate tensile strength. Statistical design of fatigue experiments was carried out to determine the sample size at each stress level. Experimental results are presented in the form of stress-life (S-N) curves and reliability-stress-life (R-S-N) curves, which are helpful for designers. The S-N curve of the aluminium-graphite composite was compared with its matrix alloy LM 25. Comparison revealed that the fatigue behaviour of the aluminium-graphite composite is superior to that of the matrix alloy

Novel Binders and Methods for Agglomeration of Ore

Energy Technology Data Exchange (ETDEWEB)

S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

2006-12-31

Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

Radon risk in ore miners

International Nuclear Information System (INIS)

Beno, M.

1997-01-01

Underground workers are exposed to various clastogenic agents. One of these agents, radon, attracts attention of recent research as it causes lung cancer in the population occupationally exposed to its various concentrations especially in mine air of uranium mines or ore mines. This paper is a pilot study in which the numbers of chromosomal aberrations (CA) in lymphocytes of ore mines (Nizna Slana-iron ore, Hnusta-talc ore) located in east central Slovakia were followed and related to the lifetime underground radon exposure and to lifetime smoking. Seventy miners volunteering after an informed consent served as donors of venous blood. Twenty healthy pro-bands, age matched with the miners, which never worked underground (mostly clerks) served as donors of control blood samples. The exposure to radon and smoking has been estimated according to working-records and personal anamnesis. The findings unequivocally showed a small but statistically significant clastogenic effect of the exposure to underground environment of the mines concerned. This study has shown also a small but significant influence of smoking, which in the subgroup of miners working underground less than 1500 shifts may have acted synergically with the underground exposure. It was concluded tat: (1) Significantly higher counts of chromosomal aberrations in lymphocytes of 70 miners than in an age matched control group of 20 white-collar workers were found; (2) The higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; (3) The positive dependence of the number of chromosomal aberrations from the exposure to smoking was loose and it was expressed by significantly higher chromosomal aberrations counts in the group of miners working less than 1500 shifts underground; (4) A dependence of chromosomal aberrations counts from the exposure to radon could not be assessed. At relatively low numbers of pro-bands in subgroups it was not ruled out the confounding

Mining and processing of uranium ores in the USSR

International Nuclear Information System (INIS)

Laskorin, B.N.; Mamilov, V.A.; Korejsho, Yu.A.

1983-01-01

Experience gained in uranium ore mining by modern methods in combination with underground and heap leaching is summarized. More intensive processing of low-grade ores has been achieved through the use of autoclave leaching, sorptive treatment of thick pulps, extractive separation of pure uranium compounds, automated continuous sorption devices of high efficiency for processing the underground- and heap-leaching liquors, natural and mine water, and recovery of molybdenum, vanadium, scandium, rare earths and phosphate fertilizers from low-grade ores. Production of ion-exchangers and extractants has been developed and processes for concomitant recovery of copper, gold, ionium, tungsten, caesium, zirconium, tantalum, nickel and cobalt have been designed. (author)

Influence of Stockpile Angle in Natural Drying of Laterite Ore

Directory of Open Access Journals (Sweden)

Yoalbys Retirado-Mediaceja

2016-10-01

Full Text Available Natural drying is performed at Cuban nickel plants by depositing bulk ore in the open. The ore is currently being stockpiled without much consideration for the impact of the drying surface angle on the process power behavior. Simulations were carried out in this investigation, which prove that an increased triangular stockpile angle considerably reduces natural drying efficiency. A 45 sexagesimal degree angle to the horizontal plane results in exposure of a large volume of ore to natural drying and guarantees adequate energy performance.

Natural galvaniv effect when bed-oxidation ore-bearing zone forming

International Nuclear Information System (INIS)

Shchetochkin, V.N.; Kislyakov, Ya.M.; Vasil'eva, Eh.G.

1995-01-01

Hypothesis of the essential role of natural galvanic process in exogenetic-epigene ore-formation the model of which was elaborated earlier, is grounded. Genetic conjuction of variations near geochemical barrier of redox and acidic-alkaline hydrogeochemical parameters is stated. These variations in total enable to understand the mechanism of formation of infiltration uranium mineralizatiuon, to explain a number of the observed peculiarities of oxidation ore-controlling zoning, and to explain, as well, slightly-expressed concentration of elements-hydrolyzates in uranium ores. 29 refs.; 6 figs.; 3 tabs

Corrosion behaviour of zinc and aluminium in simulated nuclear accident environments

International Nuclear Information System (INIS)

Piippo, J.; Laitinen, T.; Sirkiae, P.

1997-02-01

The corrosion rates of zinc and aluminium were determined in simulated large pipe break and in severe accident cases. An in situ on fine measurement technique, which is based on the resistance measurement of sample wires, was used. In the large pipe break case the corrosion rates of zinc and aluminium were determined at pH 8 and pH 10 in deaerated and in aerated solutions. Tests were also performed in aerated 0.1 M borate buffer solution at pH 9.2. Temperature range was 130 deg C - 50 deg C. The corrosion of zinc appears to be relatively fast in neutral or mildly alkaline aerated water, while both high pH and deaeration tend to reduce the corrosion rates of zinc. The aeration and pH elevation decrease the corrosion rate of aluminium. The simulation of the severe accident case took place in the pH range 3-11 in chloride containing solutions at 50 deg C temperature. The corrosion rate of aluminium was lower than that of zinc, except for the solution with pH 11, in which the corrosion rate of aluminium was practically identical to that of zinc. Both metals corroded more rapidly in the presence of chlorides in acidic and alkalic conditions than in the absence of chlorides at neutral environment. The solubility of zinc and aluminium and the stability of the corrosion products were estimated using thermodynamical calculations. The experimental results and the thermodynamical calculations were in fair agreement. (8 refs.)

Iron-ore resources of the United States including Alaska and Puerto Rico, 1955

Science.gov (United States)

Carr, Martha S.; Dutton, Carl E.

1959-01-01

The importance of iron ore, the basic raw material of steel, as a fundamental mineral, resource is shown by the fact that about 100 million long tons of steel is used annually in the economy of the United States, as compared with a combined total of about 5 million long tons of copper, lead, zinc, and aluminum. Satisfying this annual demand for steel requires about 110 million tons of iron ore and 70 million tons of scrap iron and steel. The average annual consumption of iron ore in the United States from 1951 to 1955, inclusive, was about 110 million long tons, which is about twice the annual average from 1900 to 1930. Production of iron ore in the United States in this 5-year period averaged approximately 100 million long tons annually, divided by regions as follows (in percent): Lake Superior, 84.1; southeastern, 6.7; western, 6.7; northeastern, 1.4; and central and gulf, 1.1. Mining of iron ore began in the American Colonies about 1619, and for 225 years it was limited to eastern United States where fuel and markets were readily available. Production of iron ore from the Lake Superior region began in 1846; the region became the leading domestic source by 1890, and the Mesabi range in Minnesota has been the world's most productive area since 1896. Proximity of raw materials, water transportation, and markets has resulted in centralization of the country's iron and steel industry in the lower Great Lakes area. Increased imports of iron ore being delivered to eastern United States as well as demands for steel in nearby markets have given impetus to expansion in the steel-making capacity in this area. The four chief iron-ore minerals - hematite, liminite, magnetite, and siderite - are widely distributed but only locally form deposits of sufficient tonnage and grade to be commercially valuable at the present time. The iron content of these minerals, of which hematite is the most important, ranges from 48 percent in siderite to 72 percent in magnetite, but as these

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

Indian Academy of Sciences (India)

Central Iran; iron-apatite ore; Kiruna-type; Posht-e-Badam Block; REE geochemistry. J. Earth Syst ... ferent ore genesis models have been proposed for ...... volatile-rich magma systems stress the important .... Laco magnetite flow deposits, northern Chile: An up-to- ... economic report on iron ore prevision of the Esfahan steel.

Development of solar selective absorber layers on aluminium. Final report; Entwicklung solarselektiver Absorberschichten auf Aluminium fuer Solarkollektoren. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Hoenicke, D.; Moeller, T.; Schwarz, T.

1998-01-31

A new electrolytic process was developed to form solar selective layers on aluminium. In the developed process, both the formation of the alumina layer and the deposition of metals into the layer takes place in only one treatment step using a single electrolysis bath. The main step of the so called ISOC-method (impulse structured oxide ceramic) is the anodic oxidation of aluminium which was carried out by using a pulse technique at different voltages. During the anodic polarisation a thin alumina ceramic layer was formed, while the cathodic led to the metal deposition as copper and nickel. The conditions of the electrolysis were varied in order to estimate optimal parameters achieving solar selective layers with high selectivity. Furthermore, a scale-up of the lab scale apparatus to a mini plant was carried out. Finally, the corrosion resistance of the absorber layers was improved by the formation of a thin hydrophobic overlayer using a sol-gel treatment. (orig.) [Deutsch] Ein neuartiges Behandlungsverfahren zur Erzeugung von solarselektiven Absorberschichten auf Aluminium wurde entwickelt. Bei dieser elektrochemischen Behandlung wird in einem Einstufenprozess mit einem Elektrolyten durch eine Kombination von anodischer Oxidation und bipolarer Pulsbehandlung auf der Oberflaeche des Aluminiums eine impulsstrukturierte Oxidkeramik (ISOK) erzeugt. Dabei entsteht durch eine anodische Oxidation eine strukturierte Aluminiumoxidschicht. Bei der bipolaren Pulsbehandlung erfolgt dann eine Abscheidung der im ISOK-Elektrolyten befindlichen Metalle Cu und Ni auf oder in die Aluminiumoxidoberflaeche. Die ISOK-Behandlung wurde vom Labormassstab zu einem ISOK-Verfahren im Miniplant-Massstab entwickelt. Der Einfluss der elektrischen Parameter und der chemischen Zusammensetzung der ISOK-Elektrolyte wurde untersucht. Durch eine auf das ISOK-Verfahren abgestimmte Nachbehandlung, ein Tauchverfahren in einer Sol-Gel-Loesung, entsteht ein Schichtsystem mit hoher Solarselektivitaet

Juuru Mihkli Kiriku Oreli Fond võttis endale uue ülesande / Tauno Kibur

Index Scriptorium Estoniae

Kibur, Tauno

2009-01-01

Oreli fond on võtnud ülesandeks restaureerida koguduse ajalooline pastoraat. Hoone eskiisi tegi Raivi Juks. Oreli restaureerimist ja tulemust jääb fikseerima Juuru oreli plaat, mille muusikapalad mängis sisse Kristel Aer

Friction conditions in the bearing area of an aluminium extrusion process

NARCIS (Netherlands)

Ma, X.; de Rooij, Matthias B.; Schipper, Dirk J.

2012-01-01

In aluminium extrusion processes, friction inside the bearing channel is important for controlling the surface quality of the extrusion products. The contact materials show a large hardness difference, one being hot aluminium, and the other being hardened tool steel. Further, the contact pressure is

Helium and deuterium permeability in O-rings

International Nuclear Information System (INIS)

Lakner, J.F.

1976-01-01

To obtain more information on gas permeation through elastomeric O-rings, studies were performed on Parker Seal Company O-rings, Nos. 2-113, 2-006, 3-904, and 3-906, all made of a nitrile rubber. Also included in the tests was a valve packing (Autoclave Engineers) encased in AE Valve 20A-2142. Permeation experiments were run usually in duplicate to 82.7 MPa (12,000 psi) with helium and deuterium at room temperature. The data are extrapolated to give values for tritium

Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

Science.gov (United States)

Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

2011-02-01

High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

Microcontroller based, ore grade measuring portable instruments for uranium mining industry

International Nuclear Information System (INIS)

Dheeraj Reddy, J.; Narender Reddy, J.

2004-01-01

Ore Face Scanning and Bore Hole Logging are important essential activities which are required to be carried out in any Uranium mining industry. Microcontroller based, portable instruments with built-in powerful embedded code for data acquisition (of Radiation counts) and Ore Grade calculations will become a handy measuring tool for miners. Nucleonix Systems has recently developed and made these two portable instruments available to UCIL, which are under use at Jaduguda and Narvapahar mines. Some of the important features of these systems are compact, light weight, portable, hand held, battery powered. Modes of Data Acquisition: CPS, CPM and ORE GRADE. Detector: Sensitive GM Tube. Choice of Adj. TC (Time Constant) in 'ORE GRADE', acquisition mode. Built-in automatic BG (Background) recording and subtraction provided to indicate net CPS, CPM or ore GRADE in PPM. Can store 1000 readings at users choice. Built-in RS232 serial port facilitates data downloading into PC. This paper focuses on design concepts and technical details for the above two products. (author)

Propolis Protection from Toxicity Caused by Aluminium Chloride in Male Rats

International Nuclear Information System (INIS)

Mangood, S.A.; Kamal, A.M.; Haggag, A.M.

2012-01-01

Propolis is a resinous natural hive product derived from plant exudate collected by honey bees and has been extensively used in folk medicine. The present study was undertaken to determine the effectiveness of propolis in alleviating the toxicity of aluminium chloride (AlCl 3 )on some hematological and biochemical parameters of male albino rats. Twenty four male albino rats were arranged into 4 equal groups; control group, aluminium group (34 mg AlCl 3 /kg/day), propolis group (100μg propolis/rat)and aluminium plus propolis group. Rats were orally administered their respective doses daily for 30 days. AlCl 3 caused significant decrease in hemoglobin (Hb), red blood cell count (RBC), hematocrit (Ht), total and differential leucocyte count (TLC) when compared to control. On the other hand, aluminium administration caused a significant increase in urea, uric acid, creatinin, bilirubin, the content of phosphorous, alanine aminotransferase (ALT) and asparate aminotransferase (AST) and significant decrease in total protein, albumin, globulin and calcium when compared to control. The administration of propolis alleviated the toxic effect of AlCl 3 in experimental rats. It could be concluded thal propolis my afford protection from toxicity caused by aluminium chloride in male albino rats

Characteristics of Crushing Energy and Fractal of Magnetite Ore under Uniaxial Compression

Science.gov (United States)

Gao, F.; Gan, D. Q.; Zhang, Y. B.

2018-03-01

The crushing mechanism of magnetite ore is a critical theoretical problem on the controlling of energy dissipation and machine crushing quality in ore material processing. Uniaxial crushing tests were carried out to research the deformation mechanism and the laws of the energy evolution, based on which the crushing mechanism of magnetite ore was explored. The compaction stage and plasticity and damage stage are two main compression deformation stages, the main transitional forms from inner damage to fracture are plastic deformation and stick-slip. In the process of crushing, plasticity and damage stage is the key link on energy absorption for that the specimen tends to saturate energy state approaching to the peak stress. The characteristics of specimen deformation and energy dissipation can synthetically reply the state of existed defects inner raw magnetite ore and the damage process during loading period. The fast releasing of elastic energy and the work done by the press machine commonly make raw magnetite ore thoroughly broken after peak stress. Magnetite ore fragments have statistical self-similarity and size threshold of fractal characteristics under uniaxial squeezing crushing. The larger ratio of releasable elastic energy and dissipation energy and the faster energy change rate is the better fractal properties and crushing quality magnetite ore has under uniaxial crushing.

Practice and prospect on bioleaching of uranium ore in China

International Nuclear Information System (INIS)

Liu Jian; Fan Baotuan; Meng Yunsheng; Zheng Ying; Liu Chao; Zhou Lei

2008-01-01

Developing situation on bioleaching of uranium ore in China is introduced. The selection and domestication of bacteria, development and application of biocntact oxidation tank, and practice on bioleaching of uranium ore in China are retrospeted and prospected. (authors)

Development of Technology for Enrichment of Silver Containing Ores

Science.gov (United States)

Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

2016-10-01

The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re

Beneficiation studies of Bajaur manganese ore by different processing techniques

International Nuclear Information System (INIS)

Riaz, M.; Khan, F.U.; Yamin, A.; Bilquees, R.; Muhammad, N.

2010-01-01

The manganese ore of Bajaur Agency of Pakistan was subjected to flotation, heavy medium separation, gravity concentration and magnetic separation techniques for beneficiation. The original composition of the manganese ore was 45.56% Mn , 4% Fe/sub 2/O/sub 3/, 40% SiO/sub 2/. The Mn content was raised to a maximum 48.76 % in the concentrate with the recovery of 67.78 % through flotation technique. Other techniques rendered marginal increase in Mn concentration against the theoretical possibility of substantial enrichment by rejecting the 20 % gangue minerals. The separation of manganese minerals from associated gangue was difficult, due to mineralogical complexity of the ore, extreme fineness of the particle size, texture and minerals intergrowth. High Mn/Fe ratio, phosphorus, and silica contents were within tolerable limits for utilisation of the ore in ferro-manganese production. (author)

Assessment of the contrast of rare metal ores

International Nuclear Information System (INIS)

Kuznetsova, O.V.

1987-01-01

The method of rapid assessment of useful component content on the basis of X-ray radiometric method of analysis of non-crushed ore lumps is presented. Using as an example rare metal deposits, linear dependence between logarithms of Nb 2 O 6 contents and the value of fragment separation index during radiometric separation is established. The use of the dependence ensures sufficient accuracy for the characteristic of rare metal ore content

Ore bearing system and hydrological characteristics of mineralized sector in Hushiliang area

International Nuclear Information System (INIS)

Zhang Zhaolin; Liu Zhengbang; Miao Aisheng

2010-01-01

Hushiliang area is one of the best uranium ore bearing areas in Erdos basin from the point of fluvial sedimentary system and uranium geochemical environment, So far, three mineralized sector has been found that are Nalingou, Nongshengxin, Baobeigou. By using the first-hand data of uranium regional survey in this area lately and systematically comparing and analyzing of the hydrological structure in the mineralized sector of this area, the thesis ascertain the ore and water bearing fluid reservoir's spatial relationship generally, and argues that the Zhiluo formation ore and water bearing fluid reservoir in this area is a unified underwater ore bearing system, and the orebody's hydrological structure is propitious in the distributary channel and unpropitious in the main channel because of deep ore bearing layer to the ISL. (authors)

Technology of Polish copper ore beneficiation – perspectives from the past experience

Directory of Open Access Journals (Sweden)

Wieniewski Andrzej

2016-01-01

Full Text Available The paper describes the main types of existing copper deposits in the world and the most common enrichment technologies. The characteristic elements of the current flowsheet of the Polish ore beneficiation were discussed together with the reasons for using them. The paper presents a perspective flowsheet based on more than 50-years of experience in beneficiation of Polish copper ore. The main elements of proposed technology are: leaving in justified cases the division of ore into fractions of increased sandstone and carbonate ores content, flotation in the milling circuit as part of the effective preparation of the ore to rougher flotation, intensive rougher flotation, classic cleaning system, processing of the middlings with grinding system in new type mills, classification and flotation with outlet of final tailings.

High-purity aluminium creep under high hydrostatic pressure

International Nuclear Information System (INIS)

Zajtsev, V.I.; Lyafer, E.I.; Tokij, V.V.

1977-01-01

The effect of the hydrostatic pressure on the rate of steady-state creep of high-purity aluminium was investigated. It is shown that the hydrostatic pressure inhibits the creep. The activation volume of the creep is independent of the direction in the range of (4.7-6.2) kg/mm 2 and of the pressure in the range of (1-7.8000) atm. It is concluded that self-diffusion does not control the creep of high-purity aluminium at room temperature in the investigated stress and pressure range

Contradictory effect of chromate inhibitor on corrosive wear of aluminium alloy

International Nuclear Information System (INIS)

Pokhmurskii, V.I.; Zin, I.M.; Vynar, V.A.; Bily, L.M.

2011-01-01

Research highlights: → Corrosive wear of aluminium alloy in inhibited artificial acid rain was studied. → Tribometer with linear reciprocating ball-on-flat geometry was used.→ Corrosion potential, polarization current and friction coefficient were measured. → Chromate decreases corrosion of aluminium alloy under wear conditions. → Chromate in general accelerates corrosive wear of the alloy in acid rain. - Abstract: The corrosive wear of D16T aluminium alloy in artificial acid rain was studied. A special tribometer with the linear reciprocating ball-on-flat geometry was used. The setup allows to measure simultaneously an open circuit potential, to carry out potentiostatic and potentiodynamic polarization studies of the alloy corrosion and to record the friction coefficient. It was established that the addition of strontium chromate inhibitor to the working environment decreases an electrochemical corrosion of the aluminium alloy under wear conditions, but in general accelerates its destruction due to insufficient wear resistance of a formed surface film.

A study of aluminium-exposed fish using a scanning proton microprobe

Energy Technology Data Exchange (ETDEWEB)

Cholewa, M; Legge, G L.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Eeckhaoudt, S; Van Grieken, R [Universitaire Instelling Antwerpen, Antwerp (Belgium)

1994-12-31

A major problem has arisen in Europe with the depopulation of fresh water fish in lakes and streams collecting acid rain. The sensitivity to acidification is species specific and appears to be associated with metal levels. The Scanning Proton Microprobe (SPMP) at the Micro Analytical Research Centre of the University of Melbourne was used to study the subcellular distribution of aluminium and other elements in the gills of fish exposed to acidified water with elevated Al-levels. Experiments were performed on thin sections taken from fish exposed to media with different pH and aluminium concentration. Aluminium was found on the surface of the gill lamellae, but also inside the tissue. Bulk analysis of the gills showed much higher concentrations in the aluminium-exposed fish, compared to the control ones, but no information regarding the actual accumulation sites can be inferred. Extensive study of damage done to the sample by intense proton beams during elemental analysis was performed with scanning transmission ion microscopy. 3 refs., 3 figs.

A study of aluminium-exposed fish using a scanning proton microprobe

Energy Technology Data Exchange (ETDEWEB)

Cholewa, M.; Legge, G.L.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Eeckhaoudt, S.; Van Grieken, R. [Universitaire Instelling Antwerpen, Antwerp (Belgium)

1993-12-31

A major problem has arisen in Europe with the depopulation of fresh water fish in lakes and streams collecting acid rain. The sensitivity to acidification is species specific and appears to be associated with metal levels. The Scanning Proton Microprobe (SPMP) at the Micro Analytical Research Centre of the University of Melbourne was used to study the subcellular distribution of aluminium and other elements in the gills of fish exposed to acidified water with elevated Al-levels. Experiments were performed on thin sections taken from fish exposed to media with different pH and aluminium concentration. Aluminium was found on the surface of the gill lamellae, but also inside the tissue. Bulk analysis of the gills showed much higher concentrations in the aluminium-exposed fish, compared to the control ones, but no information regarding the actual accumulation sites can be inferred. Extensive study of damage done to the sample by intense proton beams during elemental analysis was performed with scanning transmission ion microscopy. 3 refs., 3 figs.

Process Simulation of Aluminium Sheet Metal Deep Drawing at Elevated Temperatures

International Nuclear Information System (INIS)

Winklhofer, Johannes; Trattnig, Gernot; Lind, Christoph; Sommitsch, Christof; Feuerhuber, Hannes

2010-01-01

Lightweight design is essential for an economic and environmentally friendly vehicle. Aluminium sheet metal is well known for its ability to improve the strength to weight ratio of lightweight structures. One disadvantage of aluminium is that it is less formable than steel. Therefore complex part geometries can only be realized by expensive multi-step production processes. One method for overcoming this disadvantage is deep drawing at elevated temperatures. In this way the formability of aluminium sheet metal can be improved significantly, and the number of necessary production steps can thereby be reduced. This paper introduces deep drawing of aluminium sheet metal at elevated temperatures, a corresponding simulation method, a characteristic process and its optimization. The temperature and strain rate dependent material properties of a 5xxx series alloy and their modelling are discussed. A three dimensional thermomechanically coupled finite element deep drawing simulation model and its validation are presented. Based on the validated simulation model an optimised process strategy regarding formability, time and cost is introduced.

A study of aluminium-exposed fish using a scanning proton microprobe

International Nuclear Information System (INIS)

Cholewa, M.; Legge, G.L.F.

1993-01-01

A major problem has arisen in Europe with the depopulation of fresh water fish in lakes and streams collecting acid rain. The sensitivity to acidification is species specific and appears to be associated with metal levels. The Scanning Proton Microprobe (SPMP) at the Micro Analytical Research Centre of the University of Melbourne was used to study the subcellular distribution of aluminium and other elements in the gills of fish exposed to acidified water with elevated Al-levels. Experiments were performed on thin sections taken from fish exposed to media with different pH and aluminium concentration. Aluminium was found on the surface of the gill lamellae, but also inside the tissue. Bulk analysis of the gills showed much higher concentrations in the aluminium-exposed fish, compared to the control ones, but no information regarding the actual accumulation sites can be inferred. Extensive study of damage done to the sample by intense proton beams during elemental analysis was performed with scanning transmission ion microscopy. 3 refs., 3 figs

Study of Surface Roughness and Cutting force in machining for 6068 Aluminium alloy

Science.gov (United States)

Purushothaman, D.; Kaushik Yanamundra, Krishna; Krishnan, Gokul; Perisamy, C.

2018-04-01

Metal matrix composites, in particular, Aluminium Hybrid Composites are gaining increasing attention for applications in air and land because of their superior strength to weight ratio, density and high temperature resistance. Aluminium alloys are being used for a wide range of applications in Aerospace and Automobile industries, to name a few. The Aluminium Alloy 6068 has been used as the specimen. It is mainly composed of Aluminium (93.22 - 97.6 %), Magnesium (0.60 - 1.2 %), Silicon (0.60 - 1.4 %) and Bismuth (0.60 - 1.1 %). Aluminium 6068 is widely used for manufacturing aircraft structures, fuselages and wings. It is also extensively used in fabricating automobile parts such as wheel spacers. In this study, tests for the measurement of surface roughness and cutting force has been carried out on the specimen, the results evaluated and conclusions are drawn. Also the simulation of the same is carried out in a commercial FE software – ABAQUS.

The quality of our drinking water: aluminium determination with an acoustic wave sensor.

Science.gov (United States)