scholarly journals Variability and Bias in Measurements of Metals Mass Fractions in Automobile Shredder Residue

Recycling ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 34 ◽  
Author(s):  
Løvik ◽  
Figi ◽  
Schreiner ◽  
Rösslein ◽  
Widmer ◽  
...  
Keyword(s):  
Trace Metals ◽  
Chemical Analysis ◽  
Sample Preparation ◽  
Resource Potential ◽  
Shredder Residue ◽  
Automobile Shredder Residue ◽  
Mass Fractions ◽  
Systematic Effects ◽  
Wet Chemical ◽  
Good Agreement

The treatment of end-of-life vehicles generates large amounts of automobile shredder residue (ASR), a potential source of recycled metals. Reliable measurement methods are required to determine the composition of ASR and evaluate the resource potential. We reported on research undertaken to investigate bias and variability in the process of measuring trace metals in ASR. Two primary samples of shredder light fraction (SLF) underwent extensive physical sample preparation and chemical analysis. The samples were spiked to control random variations and systematic effects during physical sample preparation. Chemical analysis was conducted using wavelength-dispersive X-ray fluorescence spectrometry (WD-XRF), a fully validated wet-chemical analysis, and a wet-chemical analysis representing an “in-house” lab procedure. Physical sample preparation introduced deviations up to a factor of 2, likely due to preferential losses and heterogeneity. Deviations for WD-XRF measurements of elements were in the range +100%/−50%. In-house chemical analysis produced results that were in good agreement with validated results for Al, Fe and Sn, but led to biased results or high variability for Cd, Dy, La, Nd, Pb, Pd, Pt and Sb. To improve the chemical analysis of trace metals in SLF, we recommended reducing particle size to less than 0.1 mm before chemical analysis and using a larger number of repeated digestions.

scholarly journals Characterizing the Urban Mine–Challenges of Simplified Chemical Analysis of Anthropogenic Mineral Residues

Resources ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 132 ◽  
Author(s):  
Mählitz ◽  
Løvik ◽  
Figi ◽  
Schreiner ◽  
Kuntz ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Chemical Analysis ◽  
Lithium Ion ◽  
Reference Value ◽  
Spectral Lines ◽  
Internal Quality ◽  
Xrf Analysis ◽  
Analysis Methods ◽  
Mass Fractions ◽  
Wet Chemical

Anthropogenic mineral residues are characterized by their material complexity and heterogeneity, which pose challenges to the chemical analysis of multiple elements. However, creating an urban mine knowledge database requires data using affordable and simple chemical analysis methods, providing accurate and valid results. In this study, we assess the applicability of simplified multi-element chemical analysis methods for two anthropogenic mineral waste matrices: (1) lithium-ion battery ash that was obtained from thermal pre-treatment and (2) rare earth elements (REE)-bearing iron-apatite ore from a Swedish tailing dam. For both samples, simplified methods comprising ‘inhouse’ wet-chemical analysis and energy-dispersive Xray fluorescence (ED-XRF) spectrometry were compared to the results of the developed matrix-specific validated methods. Simplified wet-chemical analyses showed significant differences when compared to the validated method, despite proven internal quality assurance, such as verification of sample homogeneity, precision, and accuracy. Matrix-specific problems, such as incomplete digestion and overlapping spectra due to similar spectral lines (ICP-OES) or element masses (ICP-MS), can result in quadruple overestimations or underestimation by half when compared to the reference value. ED-XRF analysis proved to be applicable as semi-quantitative analysis for elements with mass fractions higher than 1000 ppm and an atomic number between Z 12 and Z 50. For elements with low mass fractions, ED-XRF analysis performed poorly and showed deviations of up to 90 times the validated value. Concerning all the results, we conclude that the characterization of anthropogenic mineral residues is prone to matrix-specific interferences, which have to be addressed with additional quality assurance measures.

Sector growth and symmetry of (F,OH) apatite from the Asio mine, Japan

1994 ◽  
Vol 58 (391) ◽  
pp. 307-314 ◽  
Author(s):  
Mizuhiko Akizuki ◽  
Hirotugu Nisidoh ◽  
Yasuhiro Kudoh ◽  
Tomohiro Watanabe ◽  
Kazuo Kurata
Keyword(s):  
Optical Properties ◽  
Crystal Growth ◽  
Electron Diffraction ◽  
Chemical Analysis ◽  
Growth Surface ◽  
Complete Disappearance ◽  
X Ray ◽  
Solid Crystal ◽  
Wet Chemical ◽  
Growth Features

AbstractA study of apatite crystals from the Asio mine, Japan, showed sectoral texture related to the growth of the crystal, and with optically biaxial properties within the sectors. Wet chemical analysis gave a composition Ca5(PO4)3(F0.64,OH0.38,Cl0.01)1.03 for the specimen.Additional diffraction spots were not observed in precession and oscillation X-ray photographs and electron diffraction photographs. Since the internal textures correlate with the surface growth features, it is suggested that the internal textures and the unusual optical properties were produced during nonequilibrium crystal growth. The fluorine/hydroxyl sites in hexagonal apatite are symmetrically equivalent in the solid crystal but, at a growth surface, this equivalence may be lost, resulting in a reduction of crystal symmetry. Heating of the apatite to about 850°C results in the almost complete disappearance of the optical anomalies due to disordering, which may be related to the loss of hydroxyl from the crystal.

Pyrolysis process for treatment of automobile shredder residue: preliminary experimental results

2001 ◽  
Vol 42 (5) ◽  
pp. 573-586 ◽  
Author(s):  
S Galvagno ◽  
F Fortuna ◽  
G Cornacchia ◽  
S Casu ◽  
T Coppola ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pyrolysis Process ◽  
Shredder Residue ◽  
Automobile Shredder Residue

Thermodynamical Calculations and Experimental Confirmation about the Mg-Al-Spinel Reaction Path in the Sol-Gel-Process

2006 ◽  
Vol 317-318 ◽  
pp. 135-138 ◽  
Author(s):  
Wilfried Wunderlich ◽  
Krupathi Vishista ◽  
Francis D. Gnanam ◽  
Daniel Doni Jayaseelan
Keyword(s):  
Thermal Analysis ◽  
Reaction Path ◽  
Sol Gel ◽  
Chemical Processing ◽  
Aluminium Isopropoxide ◽  
Spinel Formation ◽  
Sol Gel Process ◽  
Wet Chemical ◽  
Enthalpy Data ◽  
Good Agreement

The aim of this research is, to clarify which route the sol-gel-process is taking in the case of a Al-Mg-spinel slurry, in particular, whether the hydrolysis reaction or the spinel formation is faster and which of the intermediate hydroxide phases Al(OH)3, and Mg(OH)2, or MgO and Al2O3 or MgAl2O4H2O are formed during the spinel formation. The spinel-alloy was produced using the polymeric route during wet chemical processing. Aluminium-isopropoxide was hydrolyzed in order to form the boehmite-sol and then the same amount of magnesia was added and mixed. This sol precipitated as boehmite (AlOOH) and brucite (Mg(OH)2) after ageing for 12h as confirmed by differential thermal analysis (DTA), and differential thermal gravity (DTG) measurements. After that, the powders were subsequently annealed at 900oC for 3h in air and observed by TEM. Calculations using thermodynamic enthalpy data are in good agreement with the experiments and can be used to predict reaction paths in other system as well.

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