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Description of an aerodynamic levitation apparatus with applications in Earth sciences.

Pack A, Kremer K, Albrecht N, Simon K, Kronz A - Geochem. Trans. (2010)

Bottom Line: We apply aerodynamic levitation to bulk rocks in preparation for microchemical analyses, and for evaporation and reduction experiments.Levitation of metal oxide-rich material in a mixture of H2 and Ar resulted in the exsolution of liquid metal.Reduction of oxides to metal is a means for the extraction and analysis of siderophile elements from silicates and can be used to better understand the origin of chondritic metal.

View Article: PubMed Central - HTML - PubMed

Affiliation: Georg-August-Universität, Geowissenschaftliches Zentrum, Goldschmidtstraße 1, D-37077 Göttingen, Germany. apack@uni-goettingen.de.

ABSTRACT

Background: In aerodynamic levitation, solids and liquids are floated in a vertical gas stream. In combination with CO2-laser heating, containerless melting at high temperature of oxides and silicates is possible. We apply aerodynamic levitation to bulk rocks in preparation for microchemical analyses, and for evaporation and reduction experiments.

Results: Liquid silicate droplets (~2 mm) were maintained stable in levitation using a nozzle with a 0.8 mm bore and an opening angle of 60°. The gas flow was ~250 ml min-1. Rock powders were melted and homogenized for microchemcial analyses. Laser melting produced chemically homogeneous glass spheres. Only highly (e.g. H2O) and moderately volatile components (Na, K) were partially lost. The composition of evaporated materials was determined by directly combining levitation and inductively coupled plasma mass spectrometry. It is shown that the evaporated material is composed of Na > K > Si. Levitation of metal oxide-rich material in a mixture of H2 and Ar resulted in the exsolution of liquid metal.

Conclusions: Levitation melting is a rapid technique or for the preparation of bulk rock powders for major, minor and trace element analysis. With exception of moderately volatile elements Na and K, bulk rock analyses can be performed with an uncertainty of ± 5% relative. The technique has great potential for the quantitative determination of evaporated materials from silicate melts. Reduction of oxides to metal is a means for the extraction and analysis of siderophile elements from silicates and can be used to better understand the origin of chondritic metal.

No MeSH data available.


Related in: MedlinePlus

Plot of the composition of the evaporated gas/aerosol from picrite PB-63 vs. number of cycles (7.7 cycl s-1). The signals were smoothed with a moving average of 20 cycles.
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Figure 12: Plot of the composition of the evaporated gas/aerosol from picrite PB-63 vs. number of cycles (7.7 cycl s-1). The signals were smoothed with a moving average of 20 cycles.

Mentions: More than 80 wt.% of the aerosol was Na and K (Fig. 12). Both elements showed a strong correlation in the evaporated material. The Na/K-mass ratio in the evaporated material was in the range between 0.9 and 1.2. The amount of Si in the evaporated material varied between ~5 and ~18 wt.%. The Si-content increased with increasing temperature. Minor components in the evaporated material were Mg and Fe; both occurring in the 1 wt.% concentration level at the highest temperatures (Fig. 13). Other elements were only present as trace components in the evaporated material.


Description of an aerodynamic levitation apparatus with applications in Earth sciences.

Pack A, Kremer K, Albrecht N, Simon K, Kronz A - Geochem. Trans. (2010)

Plot of the composition of the evaporated gas/aerosol from picrite PB-63 vs. number of cycles (7.7 cycl s-1). The signals were smoothed with a moving average of 20 cycles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2958152&req=5

Figure 12: Plot of the composition of the evaporated gas/aerosol from picrite PB-63 vs. number of cycles (7.7 cycl s-1). The signals were smoothed with a moving average of 20 cycles.
Mentions: More than 80 wt.% of the aerosol was Na and K (Fig. 12). Both elements showed a strong correlation in the evaporated material. The Na/K-mass ratio in the evaporated material was in the range between 0.9 and 1.2. The amount of Si in the evaporated material varied between ~5 and ~18 wt.%. The Si-content increased with increasing temperature. Minor components in the evaporated material were Mg and Fe; both occurring in the 1 wt.% concentration level at the highest temperatures (Fig. 13). Other elements were only present as trace components in the evaporated material.

Bottom Line: We apply aerodynamic levitation to bulk rocks in preparation for microchemical analyses, and for evaporation and reduction experiments.Levitation of metal oxide-rich material in a mixture of H2 and Ar resulted in the exsolution of liquid metal.Reduction of oxides to metal is a means for the extraction and analysis of siderophile elements from silicates and can be used to better understand the origin of chondritic metal.

View Article: PubMed Central - HTML - PubMed

Affiliation: Georg-August-Universität, Geowissenschaftliches Zentrum, Goldschmidtstraße 1, D-37077 Göttingen, Germany. apack@uni-goettingen.de.

ABSTRACT

Background: In aerodynamic levitation, solids and liquids are floated in a vertical gas stream. In combination with CO2-laser heating, containerless melting at high temperature of oxides and silicates is possible. We apply aerodynamic levitation to bulk rocks in preparation for microchemical analyses, and for evaporation and reduction experiments.

Results: Liquid silicate droplets (~2 mm) were maintained stable in levitation using a nozzle with a 0.8 mm bore and an opening angle of 60°. The gas flow was ~250 ml min-1. Rock powders were melted and homogenized for microchemcial analyses. Laser melting produced chemically homogeneous glass spheres. Only highly (e.g. H2O) and moderately volatile components (Na, K) were partially lost. The composition of evaporated materials was determined by directly combining levitation and inductively coupled plasma mass spectrometry. It is shown that the evaporated material is composed of Na > K > Si. Levitation of metal oxide-rich material in a mixture of H2 and Ar resulted in the exsolution of liquid metal.

Conclusions: Levitation melting is a rapid technique or for the preparation of bulk rock powders for major, minor and trace element analysis. With exception of moderately volatile elements Na and K, bulk rock analyses can be performed with an uncertainty of ± 5% relative. The technique has great potential for the quantitative determination of evaporated materials from silicate melts. Reduction of oxides to metal is a means for the extraction and analysis of siderophile elements from silicates and can be used to better understand the origin of chondritic metal.

No MeSH data available.


Related in: MedlinePlus