scholarly journals The Dual Paradigm of Mining Waste: “From Ecotoxicological Sources to Potential Polymetallic Resources”—An Example from Iberian Pyrite Belt (Portugal)

2021 ◽  
Vol 5 (1) ◽  
pp. 23
Author(s):  
Sofia Barbosa ◽  
António Dias ◽  
Ana Ferraz ◽  
Sandra Amaro ◽  
M. Graça Brito ◽  
...  
Keyword(s):  
Clustering Analysis ◽  
Environmental Remediation ◽  
Element Concentration ◽  
Chemical Elements ◽  
Mine Waste ◽  
Distribution Patterns ◽  
Iberian Pyrite Belt ◽  
Industrial Heritage ◽  
X Ray

The main goal of this study was to identify potential chemical elements present in three types of polymetallic mine waste, stored in the old mine site of São Domingos, located in the Iberian Pyrite Belt, Alentejo, Southern Region of Portugal. This study involves the characterization of potential resources in those mine residues, bearing in mind that its reprocessing can facilitate the environmental remediation and rehabilitation activities which are underway at the site. X-ray Fluorescence (XRF) and micro (μ)-XRF 2D mapping surveys were performed. Univariate and multivariate data analysis reveal that differences in compositions are mainly related with element concentration per type of waste. Image processing and clustering analysis allowed the recognition of distinct elemental spatial distribution patterns. Some of these residues, although classified as archeological-industrial heritage materials may present toxicity to the ecological environment and to human health. This fact enhances, therefore, geoethical doubts regarding its remining and exploitability. In this context, a multi-criteria decision analysis considering two geoethical alternatives was performed.

Growth Kinetics and Mechanical Characterization of a Hard Boron Coating on a Tool Steel

2017 ◽  
Vol 380 ◽  
pp. 29-34 ◽  
Author(s):  
D. Sánchez Huerta ◽  
N. López Perrusquia ◽  
I. Hilerio Cruz ◽  
M.A. Doñu Ruiz ◽  
E.D. García Bustos ◽  
...  
Keyword(s):  
Activation Energy ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Chemical Elements ◽  
Thermochemical Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optimal Classification

The mechanical characteristics are determined to a FeB/Fe2B coating applied in AISI L6 steel tool and blades make to cut paper. The thermochemical treatment was applied at temperatures of 1173, 1223 and 1273 K with permanence time of 0.5, 2 and 3 h for each temperature. The diffusion coefficient and activation energy for each phase is obtained for this boron coating on an AISI L6 steel. HRC test were made to establish the type of adherence (qualitative) and comparing with the VDI 3198 standard and the results were obtaining optimal classification of HF1-HF2 in condition for 3h of the three temperatures. The result by nanoidentation show hardness of 1000 - 2000 HV as well as the Young's modulus for each present phase of the coating. Through micrographs (SEM) are showing thicknesses up to 79.52 ± 18.82 μm for FeB and 97.80 ± 20.01μm for Fe2B, a morphology sawn ́s type is evidence. Through EDS and x-ray diffraction are used to show the chemical elements formed.

scholarly journals THE ICOSAHEDRAL PHASE OF Al63Cu25Fe12 SYSTEM

2019 ◽  
Vol 28 (1) ◽  
pp. 51-56
Author(s):  
Anastazia Melnik ◽  
Luciano Nascimento
Keyword(s):  
Chemical Elements ◽  
Stoichiometric Composition ◽  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ideal Composition ◽  
Diffraction Patterns

The present work aimed to characterize the microstructure of the icosahedral phase (quasicrystalline phase-ϕ) of the system with stoichiometric composition of the quasicrystal Al63Cu25Fe12. The ternary alloy with nominal composition of Al63Cu25Fe12 was processed by mechanical alloying (MA) as a viable solid state processing method for producing various metastable and stable quasicrystalline phases. The structural characterization of the obtained samples was performed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), while the elemental composition of the chemical elements Al, Fe and Cu were determined by X-ray spectroscopy technique of dispersive energy (EDS). According to the results of XRD, the diffraction patterns of Al63Cu25Fe12 showed the presence of β-Al(Fe, Cu) and λ-Al13Fe4 phases coexist with the thermodynamic ϕ-phase quasicrystalline. Finally, elemental analysis indicates that during alloy synthesis there is little variation of the ideal composition. The results indicate that alloys with high percentage of icosahedral phase can be obtained by casting in the air.

X-ray photoelectron spectroscopy characterization of aerosol particles in Antarctica

2015 ◽  
Vol 27 (5) ◽  
pp. 493-499 ◽  
Author(s):  
Simona Rella ◽  
Cosimino Malitesta
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Chemical Elements ◽  
Aerosol Particles ◽  
Qualitative And Quantitative Analysis ◽  
Surface Enrichment ◽  
X Ray ◽  
Qualitative And Quantitative

AbstractQualitative and quantitative analysis of surface species on size-segregated atmospheric particulate collected in Antarctica during the 2010–11 summer was performed by X-ray photoelectron spectroscopy (XPS). This represents the first example of surface characterization of Antarctic aerosols. The size class with particle cut-off diameter of 3 μm was richest in terms of chemical elements. Peculiar findings of the application included detection of Ca (possibly surface-segregated) and surface enrichment of Mg. The determination of nitrate, ammonium and sulphate species on collection filters provides evidence for a possible advantage of XPS over more laborious techniques (e.g. ion chromatography). The presence of these species is in reasonable agreement with other recent reports from Antarctica.

scholarly journals Chemical characterization of PM10 in two small towns located in South Poland

Nukleonika ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 29-34
Author(s):  
Anna Turek-Fijak ◽  
Joanna Brania ◽  
Katarzyna Styszko ◽  
Damian Zięba ◽  
Zdzisław Stęgowski ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Chemical Elements ◽  
Chemical Characterization ◽  
Small Towns ◽  
Ray Method ◽  
Air Samples ◽  
X Ray ◽  
Limit Value ◽  
High Concentrations

Abstract The purpose of this study is to analyse the elements and PM10 concentrations in air samples gathered in the winter of 2017/2018 in two small towns, namely Skala and Wadowice. The chemical elements were identified for each sample using the energy dispersive X-ray method. The spectrometer was equipped, among others, with an Mo-X-ray tube which was the source of the photons and the Si(Li) detector. The following chemical elements: Cl, K, Fe, Ca, Zn, Pb, Br, Ti, Cu, Mn, V, Co, Rb, Ni, Sr, and Cr were identified in the samples. In addition, As and Se were identified in Wadowice. First, the results were compared with each other and then with the results for the nearest city. It was observed that the PM10 concentrations were significantly higher than the UE limit value for PM10, which equals 50 μg·m−3 per 24 h. Moreover, the high concentrations of, among others, K, Pb, Cl or Zn, are likely to be linked with fossil fuels combustion and biomass burning. The levels of element concentrations in Wadowice and Skala resemble the levels observed several years earlier in Krakow.

scholarly journals Physical chemical characterization of historical mining waste and ARD prediction tests

2017 ◽  
Vol 18 ◽  
pp. 01031
Author(s):  
Antoneta Filcenco-Olteanu ◽  
Lena Alakangas ◽  
Antoio Fiuza ◽  
Marius Zlagnean ◽  
Nicolae Tomus
Keyword(s):  
Chemical Elements ◽  
Mine Waste ◽  
Chemical Characterization ◽  
Dissolved Metals ◽  
Acid Base ◽  
Metal Mining ◽  
Acid Generation ◽  
Waste Dumps ◽  
Baia Mare

There are thousands of historical mine tailings and metallurgical residues present on inactive metal mining sites which have been abandoned. However, the potential release of dissolved metals, acidity, or suspended particulates from mine-waste dumps can be a serious and long-lasting problem. A variety of environmental impacts may occur at this abandoned mine sites and leading the list is acid generation, which is one of the main problems from metal mining. The objective of the present study was to characterize and evaluate the Romanian historical tailing of Sasar-Red Valley, near Baia Mare. This involved physical and chemical characterization of the materials and its acid generating potential. Sasar tailing impoundment contains 8.5 million m3 of tailings and occupies an area of 32.5 hectares. Tailings samples were collected from different depths in three sampling points, and characterized by grain size, chemical elements concentration, elements distribution of elements in depth, paste pH, acid-base account and net acid generation tests. Acid base accounting (ABA) tests in conjunction with net acid generation (NAG) tests classified the samples into the category of ‘potentially acid generating’. This paper presents a synthesis of works performed in the Improve Resource Efficiency and Minimize Environmental Footprint (REMinE) project.

scholarly journals FLUORESCÊNCIA DE RAIOS X POR DISPERSÃO DE ENERGIA APLICADA À CARACTERIZAÇÃO DE TIJOLOS DE SÍTIOS HISTÓRICOS DE PERNAMBUCO

2019 ◽  
Vol 34 (1) ◽  
pp. 163
Author(s):  
Helen Jamil Khoury ◽  
Roberto Araújo ◽  
Sandra De Brito Barreto ◽  
Viviane Khoury Asfora
Keyword(s):  
Chemical Elements ◽  
Raw Materials ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Para Determinar ◽  
Historical Sites ◽  
Non Destructive

No presente trabalho são 1 apresentados os resultados de estudos por fluorescência de raios X de tijolos brasileiros. Neste estudo foram avaliados 22 tijolos, sendo sete de Igarassu, dois do Forte do Brum e 13 de Olinda. Um equipamento portátil de fluorescência de raios X por dispersão de energia foi desenvolvido para este estudo. Análises por difração de raios X também foram efetuadas para determinar as fases cristalinas presentes nos tijolos. Os resultados mostraram a existência de fases minerais, como quartzo, em todos os tijolos avaliados. A Análise da Componente Principal foi aplicada aos dados dos espectros de fluorescência de raios X obtidos. Os resultados mostraram que a partir do gráfico de scores das componentes principais CP1 e CP3, respectivamente representadas pelo Fe e Ca, foi possível separar os tijolos de Igarassu e do Forte do Brum em cinco grupos, que estavam associados com o século de fabricação. Por sua vez, os tijolos de Olinda foram separados em dois grupos, sendo um formado por um único tijolo e o outro grupo pelos demais tijolos. Estes resultados sugerem que os tijolos foram produzidos com diferentes matérias primas ou em diferentes locais. ENERGY DISPERSIVE X-RAY FLUORESCENCE APPLIED TO THE CHARACTERIZATION OF BRICKS OF PERNAMBUCO HISTORICAL SITESABSTRACTThis work presents the results of X-ray fluorescence analysis of Brazilian bricks, collected from several historical sites of the State of Pernambuco, Brazil. In this study, twenty two bricks were analyzed; seven from Igarassu, two from Forte do Brum in Recife, and thirteen from Olinda. A portable X-ray fluorescence system was assembled and used for the qualitative determination of the chemical elements present in the samples. X-ray diffraction analysis was also carried out to determine the crystal mineral phases in the bricks. All the bricks studied showed several minerals, such as quartz A Principle Component Analysis was applied to the full X-ray fluorescence spectra. In the score plot of principal components PC1 and PC3, represented by Fe and Ca respectively, it can be seen that the results for the bricks from Igarassu and Forte do Brum may be grouped in five clusters corresponding to the bricks´ century and manufacture locations. The analysis of the Olinda bricks yielded two separate groups, one with a single brick and the second group with the other eleven bricks. These results suggest that the bricks were produced with different raw-materials or manufactured in different locations.KEYWORDS: non-destructive analysis; X-ray fluorescence; cultural heritage; bricks; X-ray diffraction.

scholarly journals Physical characterization of hafnium aluminates dielectrics deposited by atomic layer deposition

2015 ◽  
Vol 10 (1) ◽  
pp. 49-58
Author(s):  
Danilo R. Huanca ◽  
V. Christiano ◽  
C. Adelmann ◽  
Patrick Verdonck ◽  
Sebastião G. Dos Santos Filho
Keyword(s):  
Atomic Layer Deposition ◽  
Chemical Elements ◽  
Atomic Layer ◽  
Homogeneous Distribution ◽  
Gyration Radius ◽  
Crystalline Phases ◽  
X Ray ◽  
Layer Deposition ◽  
Scanning Electron

Hafnium aluminates films with 50 mol% of Hf were deposited onto Si(100) using atomic layer deposition. The films were annealed by RTP at 1000 oC for 60 s in pure N2 or N2+5%O2 and by LASER at 1200oC for 1ms in pure N2. Then, they were characterized by X-ray spectroscopies, ellipsometry, Rutherford backscattering and scanning electron microscopy. For thin films annealed by RTP in N2, phase separation takes place, promoting the formation of HfO2 and Al2.4 O3.6 crystalline phases. In contrast, the films annealed by LASER remain predominantly amorphous with crystalline facets of Al2.4O3.6. Also, non-homogeneous distribution of the chemical elements within the dielectrics gave rise to the formation of several regions which can be viewed as sub-layers, each of them with arbitrary electron density and thickness. As a result, Kratky curves pointed out to the coexistence of different features described by different gyration radius yielding GISAXS scattering profiles with polydispersive characteristics. Finally, the samples annealed by RTP were interpreted as agglomerates of spheroids with different sizes (1.1-2.2 nm) and with different crystalline phases whereas the samples annealed by LASER were interpreted as larger spheroids of crystalline Al2.4O3.6 (1.7-2.7nm) embedded in a matrix predominantly amorphous.

PRODUCTION AND CHARACTERIZATION OF Ba2NdSbO6 COMPLEX PEROVSKITE AS A SUBSTRATE FOR YBa2Cu3O7-δ SUPERCONDUCTING FILMS

2006 ◽  
Vol 20 (08) ◽  
pp. 427-437 ◽  
Author(s):  
Q. MADUEÑO ◽  
D. A. LANDÍNEZ TÉLLEZ ◽  
J. ROA-ROJAS
Keyword(s):  
Thin Films ◽  
Chemical Elements ◽  
Compositional Analysis ◽  
Morphological Characterization ◽  
Superconducting Thin Films ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Candidate

We report systematic studies of Ba 2 NdSbO 6 as substrates for the production of YBa 2 Cu 3 O 7-δ superconducting thin films. Chemical stability and crystallographic coupling between Ba 2 NdSbO 6 and YBCO were examined by characterizing Ba 2 NdSbO 6- YBa 2 Cu 3 O 7-δ (0 to 100 vol.%) polycrystalline composites. X-ray diffraction experiments showed that Ba 2 NdSbO 6 belongs to the complex cubic perovskite family. Moreover, we determine that these materials are chemically stables, e.g. there is no chemical reaction at the interface, and the lattice parameters evidenced a matching ~ 2%. Morphological characterization of our samples was performed through scanning electron microscopy, which revealed the existence of separated grains of Ba 2 NdSbO 6 and YBa 2 Cu 3 O 7-δ. Compositional analysis of samples was performed by energy dispersive X-ray experiments, which showed the inexistence of impurities or undesired chemical elements. DC susceptibility measurements permitted us to determine that the presence of Ba 2 NdSbO 6 does not affect the critical temperature of the superconducting transition of YBa 2 Cu 3 O 7-δ. Our results evidenced that Ba 2 NdSbO 6 is an excellent candidate as a substrate for the fabrication of YBa 2 Cu 3 O 7-δ superconducting thin films.

Synthesis and Characterization of Zn doped Li(Li0.21Mn0.54Ni0.125Co0.125)O2 as the Layer Materials For Battery Applications

2018 ◽  
Vol 21 (2) ◽  
pp. 127-131
Author(s):  
S. Rumh. Kadhim ◽  
Reihan Etefagh ◽  
H. Arabi
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Elements ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
And Chemical Properties

In this paper, pure and impure nanopowders of Li(Li0.021Mn0.54Ni0.125Co0.125)O2 were prepared with different percentages (x=0.02%, 0.05%, 0.075%, 0.10%) of Zn impurity by sol-gel method, and the effect of different percentages were investigated on the structural, physical and chemical properties of the samples. These properties of samples characterized by X-ray diffraction (XRD), field-scattering microscopy (FESEM), X-ray energy spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), infrared spectroscopy (FTIR), and the results of characterization were investigation. All the reflection peaks indicate that the samples have standard α-NaFeO2 layered structure with the space group R3m, except for the super lattice ordering between 22°-25°.The FESEM images have shown that these nanoparticles have Hexagonal structures for doped and undoped nanopowders. The particle size of nanopowders in the range of 30-80 nm the chemical analysis of EDS has proven the presence of Zn in the samples. TG /DTA measurements showed weight loss in pure and impure of nanopowders. In infrared spectroscopy (FTIR), the connection bonds and chemical elements used in these nanopowders have been investigated.

scholarly journals Investigation of metals content in the fine fraction of municipal waste from Alytus Regional Landfill

Chemija ◽  
2019 ◽  
Vol 30 (3) ◽  
Author(s):  
Rugilė Kemeklytė ◽  
Algimantas Bučinskas ◽  
Gintaras Denafas
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Chemical Elements ◽  
Fine Fraction ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This study presents the results of investigation of the fine waste fraction from the Alytus Regional Landfill. The fine fraction was analysed with the aim of characterization of the chemical elements content using scanning electron microscopy, coupled with energy-dispersive spectroscopy (EDS), SEM and X-ray diffraction (XRD) analysis. Quartz SiO2, calcite CaCO3, anhydrite CaSO4, albite NaAlSi3O8, dolomite CaMg(CO3)2, microcline KAlSi3O8, periclase MgO and muscovite KNa(Al, Mg, Fe)2(Si3.1, Al0.9)O10(OH)2 minerals were identified. The quantity of C, O, Na, Mg, Al, Si, K, Ca, Fe, P, S, Cl and Ti chemical elements was determined and their percentage change after heating was calculated.

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