In the present work we report the full structural and spectroscopic characterization of an UICC crocidolite standard sample, that is a fibrous riebeckite from Koegas Mine, Northern Cape (South Africa). The chemical composition was obtained by SEM-EDS and cation site partition was retrieved by complementing chemical, Mössbauer and X-ray powder diffraction data. Cell parameters, fractional coordinates, and site scattering for M(1), M(2), M(3), M(4) were refined using the Rietveld method. The UICC crocidolite standard sample shows the chemical formula ANa0.026BNa2.000C (Fe2+2.212Fe3+2.041Mg0.747)Σ=5.000T(Si7.950Al0.022)Σ=7.972O22O(3)(OH)2, very close to that of the end-member riebeckite A□BNa2C(Fe2+3Fe3+2)Σ=5TSi8O22O(3)(OH)2, the major difference being the Fe3+/Fetot ratio of 0.48, slightly higher than the ideal ratio of 0.40. Cation site distribution of the UICC crocidolite standard sample is: [Mg0.50Fe3+0.31Fe2+1.19]Σ=2.00 at M(1); [Mg0.10Fe3+1.60Fe2+0.30]Σ=2.00 at M(2); [Mg0.15Fe3+0.13Fe2+0.72]Σ=1.00 at M(3). Refined cell parameters are: a=9.73516(19) Å, b=18.0453(3) Å, c=5.32895(9) Å, β =103.5159(12) °, V=910.23(3) Å3. Quantitative Phase Analysis indicates that 93.7(3) wt% of the sample consists of crocidolite, the remaining being distributed among five different phases including magnetite and quartz.

Chemical and structural characterization of UICC crocidolite fibres from Koegas Mine, Northern Cape (South Africa) / Pacella, A.; Andreozzi, G.; Nodari, L.; Ballirano, P.. - In: PERIODICO DI MINERALOGIA. - ISSN 0369-8963. - 88:3(2019), pp. 297-306. [10.2451/2019PM910]

Chemical and structural characterization of UICC crocidolite fibres from Koegas Mine, Northern Cape (South Africa)

Pacella A.
Membro del Collaboration Group
;
Andreozzi G.;Ballirano P.
Writing – Review & Editing
2019

Abstract

In the present work we report the full structural and spectroscopic characterization of an UICC crocidolite standard sample, that is a fibrous riebeckite from Koegas Mine, Northern Cape (South Africa). The chemical composition was obtained by SEM-EDS and cation site partition was retrieved by complementing chemical, Mössbauer and X-ray powder diffraction data. Cell parameters, fractional coordinates, and site scattering for M(1), M(2), M(3), M(4) were refined using the Rietveld method. The UICC crocidolite standard sample shows the chemical formula ANa0.026BNa2.000C (Fe2+2.212Fe3+2.041Mg0.747)Σ=5.000T(Si7.950Al0.022)Σ=7.972O22O(3)(OH)2, very close to that of the end-member riebeckite A□BNa2C(Fe2+3Fe3+2)Σ=5TSi8O22O(3)(OH)2, the major difference being the Fe3+/Fetot ratio of 0.48, slightly higher than the ideal ratio of 0.40. Cation site distribution of the UICC crocidolite standard sample is: [Mg0.50Fe3+0.31Fe2+1.19]Σ=2.00 at M(1); [Mg0.10Fe3+1.60Fe2+0.30]Σ=2.00 at M(2); [Mg0.15Fe3+0.13Fe2+0.72]Σ=1.00 at M(3). Refined cell parameters are: a=9.73516(19) Å, b=18.0453(3) Å, c=5.32895(9) Å, β =103.5159(12) °, V=910.23(3) Å3. Quantitative Phase Analysis indicates that 93.7(3) wt% of the sample consists of crocidolite, the remaining being distributed among five different phases including magnetite and quartz.
2019
Asbestos; Mössbauer Spectroscopy; Rietveld method; Scanning Electron Microscopy with Energy Dispersive System (SEM-EDS); Surface reactivity; UICC crocidolite; X-ray Powder Diffraction (XRPD)
01 Pubblicazione su rivista::01a Articolo in rivista
Chemical and structural characterization of UICC crocidolite fibres from Koegas Mine, Northern Cape (South Africa) / Pacella, A.; Andreozzi, G.; Nodari, L.; Ballirano, P.. - In: PERIODICO DI MINERALOGIA. - ISSN 0369-8963. - 88:3(2019), pp. 297-306. [10.2451/2019PM910]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1361688
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