Investigation of Mechanisms and Kinetics of the Hydrothermal

Martin Luther Universität Halle-Wittenberg
Institut für Geowissenschaften
Mineralogie/Geochemie
Prof. Dr. Dr. H. Pöllmann
Von-Seckendorff-Platz 3, 06120 Halle,
Tel: +49.345.5526111, Fax:+49.345.5527180,
e-mail: [email protected]
Investigation of Mechanisms and Kinetics of the Hydrothermal Synthesis of
Novel Hydraulic Binding Materials
Patrick Ullrich
Main issue is the investigation of the hydrothermal synthesis of crystalline and nanocrystalline
calcium-silicate-hydrates (C-S-H-phases) and especially the formation of -dicalcium-silicatehydrate (-C2SH). These materials are forming as precursor during the production of the novel
hydraulic binding material Celitement (www.celitement.de). They are produced in the main
process step, a hydrothermal synthesis in an autoclave at 200°C [Beuchle et al. 2008, Beuchle
2010].
The reactions taking place during the process in the autoclave
should be investigated directly, so called: in situ. For this
purpose, a micro-autoclave for use at the synchrotron radiation
facility ANKA (KIT, Karlsruhe) has been developed. The
experimental setup enables the conduction of a hydrothermal
synthesis at the beamline SUL-X and at the same time, the
determination of the phase composition in the reaction chamber
by x-ray diffraction (XRD, E=16keV, beam cross section: 300m
x 150m). The micro-autoclave has a reaction volume of 27l
(path length:
1mm) and can
be assembled
with
sapphire
or
diamond
windows.
Temperatures can be regulated by a
temperature controller between 70°C and
200°C (+/-1°C).
Abb. 1: Setup of the microautoclave at SUL-X.
The in situ measurements enable the direct
investigation of the processes during the
reaction. Based on the results it is now possible
to draw conclusions about reaction mechanisms
and kinetics of the formation of C-S-H-phases.
Abb. 2: Changes in the phase composition of a
synthesis of SiO2 (quartz sand) and Ca(OH)2 in 3dimensional view.
Literature:
Beuchle, G. ; Garbev, K. ; Schweike, U. ; Stemmermann, P.: Einphasiges hydraulisches Bindemittel, Verfahren zu
seiner Herstellung und mit diesem Bindemittel hergestellter Baustoff. 2008
Patentnummer: 10 2007 035 257 B3; 10 2007 035 258 B3; 10 2007 035 259 B3
Beuchle, G. ; Garbev, K. ; Schweike, U. ; Stemmermann, P.: Verfahren zur Herstellung eines belithaltigen
Bindemittels.2010; Patentnummer: EP 1 915 325 B1

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