Limits...
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.


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Cross section through the lower part of the levitation apparatus (sample chamber removed). The levitation nozzle comprised a 0.8 mm bore and an opening angle of 60°.
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Figure 3: Cross section through the lower part of the levitation apparatus (sample chamber removed). The levitation nozzle comprised a 0.8 mm bore and an opening angle of 60°.

Mentions: We used a SYNRAD 50 W CO2 laser (λ = 10.4 μm) as heat source. The laser was focused to a beam diameter of ~1.5 - 2 mm by means of a ZnSe lens (ƒ = 125 mm). The laser energy output could continuously be varied between 0 and 95%. The levitation chamber hosted the levitation nozzle. The chamber was used when conducting experiments in controlled atmospheres (e.g., under reducing conditions) were carried out (or the chamber was used during conducting experiments in controlled atmospheres). Two sapphire windows were used for video monitoring and for illumination. The top of the chamber was covered with an IR transparent ZnSe window. The levitation nozzle had an opening angle of 60° and a 0.8 mm bore (Fig. 3). It was made of aluminum. The levitation gas was regulated with a computer-controlled VÖGTLIN red-y mass flow controller (0 - 1000 mL min-1).


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

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

Cross section through the lower part of the levitation apparatus (sample chamber removed). The levitation nozzle comprised a 0.8 mm bore and an opening angle of 60°.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Cross section through the lower part of the levitation apparatus (sample chamber removed). The levitation nozzle comprised a 0.8 mm bore and an opening angle of 60°.
Mentions: We used a SYNRAD 50 W CO2 laser (λ = 10.4 μm) as heat source. The laser was focused to a beam diameter of ~1.5 - 2 mm by means of a ZnSe lens (ƒ = 125 mm). The laser energy output could continuously be varied between 0 and 95%. The levitation chamber hosted the levitation nozzle. The chamber was used when conducting experiments in controlled atmospheres (e.g., under reducing conditions) were carried out (or the chamber was used during conducting experiments in controlled atmospheres). Two sapphire windows were used for video monitoring and for illumination. The top of the chamber was covered with an IR transparent ZnSe window. The levitation nozzle had an opening angle of 60° and a 0.8 mm bore (Fig. 3). It was made of aluminum. The levitation gas was regulated with a computer-controlled VÖGTLIN red-y mass flow controller (0 - 1000 mL min-1).

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