Crystallization of a basic sodalite under hydrothermal conditions studied by MAS-NMR, XRD and DTA/DTG

authored by

Carsten Mundus, Werner Müller-Warmuth, Josef Christian Buhl

Abstract

Hydrothermal syntheses in the system Na₂O-SiO₂-Al₂O₃-H₂O, using cristobalite, corundum and mullite as starting substances, show simultaneous crystallization of basic hydrosodalite with basic cancrinite. The samples are characterized relative to their composition and the structure of the resulting products by ²⁹Si and ²⁷Al MAS-NMR spectroscopy in combination with thermal analysis and powder X-ray diffraction. By extending the reaction times up to 240h, two different mechanisms could be identified at 423 and 473 K: at elevated temperature, the formation of cancrinite starts earlier and the reaction rate is increased. In both cases, crystallization of the products is accompanied by a transformation of the cancrinite into sodalite.

Organisation(s)

Institute of Mineralogy

External Organisation(s)

University of Münster

Type

Article

Journal

European journal of mineralogy

Volume

8

Pages

231-239

No. of pages

9

ISSN

0935-1221

Publication date

22.04.1996

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Geochemistry and Petrology

Electronic version(s)

https://doi.org/10.1127/ejm/8/2/0231 (Access: Closed)