Exploration hochreiner Semmeringquarzite für die Glasindustrie

Research output: ThesisMaster's Thesis

Authors

Abstract

The main raw material for the production of clear and colored glass is high-purity quartz. The demand for high-purity quartz raw materials by the Styrian glass industry is currently covered by only two quartz sand deposits. In order to ensure supply chain security, prospection and exploration for high-purity quartz raw materials is performed within the project "MRI_Quarz - Untersuchung von Vorkommen hochwertiger Quarzrohstoffe im südöstlichen Bundesgebiet". Based on the preliminary results, the Semmering-quartzite deposit of the Karl Friesenbichler GmbH Nfg & Co KG quarry (Unterdissau, district of Weiz, Styria) was selected as the exploration target. The deposit can be geologically assigned to the Permo-Triassic metasediments of the Vorau nappe (Silvretta-Seckau nappe system), which is locally exposed in the Fischbach Window. The main criterion for classification as a high-purity quartz raw material is an Fe2O3 content of less than 0,03 m% (clear glass) and 0,5 m% (colored glass). Phengitic muscovite with an average of 5,43 m% FeO was identified as the main Fe-bearing mineral phase. In addition to the main and minor components quartz and respectively light mica, albite, alkali feldspar, apatite, barite, gorceixite, kaolinite, monazite, limonitized pyrite, rutile and zircon occur as accessories. Based on XRF measurements, the green quartzites (1607 ppm Fe2O3) can be considered suitable for colored glass production, and the white quartzites (309 ppm Fe2O3) as for white glass production. The white quartzites occur only as hydrothermally decolorized alteration zones in green quartzite and are often associated with veinlets of glassy quartzite (65 ppm Fe2O3). The alteration to high-purity quartzites is likely to have been associated with tectonic and hydrothermal activity during the opening of the Fischbach Window. In order to achieve the required high-purity qualities, selective mining and optical sorting are presumably required. The suitability of a multi-electrode resistivity measurement was investigated for future prospection work. It should be possible to differentiate the high-purity quartzites from the host rock based on their higher resistivity due to the lower mica content. It should be kept in mind, that the small-scale structure of the alteration zones could be below the resolution limit of the measurement method and potentially only massive accumulations of alteration zones can be reliably detected. In the course of this thesis, a method comparison between a portable LIBS analysis in the field and laboratory XRF is made. After previous calibration with quartzite powder compacts, which were analyzed by wavelength-dispersive XRF as part of the prospection work, LIBS readings within the limits of Si: 41-48 m%, Fe: 0-0,26 m%, Al: 0-2 m%, Mg: 0-0,07 m% and Ba: 0-0.24 m% can be considered correct. Especially Fe contents below 0,05 m% are measured accurately. Generally, it should be noted, that the Semmering-quartzites of the Fischbach Window contain alteration zones with high-purity quartz varieties that would be suitable for the production of clear or stained glass.

Details

Translated title of the contributionExploration of high-purity Semmering-quartzite for the glass industry
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date22 Mar 2024
DOIs
Publication statusPublished - 2024