Hydration of periclase at 350 degrees C to 620 degrees C and 200 MPa

Author(s)
Ilker Hakan Kuleci, Christian S. Schmidt, Erik Rybacki, Elena Petrishcheva, Rainer Abart
Abstract

The hydration of periclase to brucite was investigated experimentally. Single crystals of periclase machined to millimeter sized cubes with (100) surfaces were reacted with distilled water at temperatures of 350 to 620 ∘C and a pressure of 200 MPa for run durations of 5 to 40 minutes. Hydration produced a layer of brucite covering the surface of periclase. While the shrinking periclase largely retained its cube shape a surface roughness developed on the μm scale and eventually outward pointing spikes bounded by (111) faces emerged on the retreating faces of the periclase due to kinetic selection of less reactive (111) and (110) surfaces. The periclase to brucite conversion followed a linear rate law, where the reaction rate increased from 350 to 530 ∘C and then decreased towards higher temperature and finally vanished at about 630 ∘C, where periclase, brucite, and water are in equilibrium at 200 MPa. The overall kinetics of the hydration reaction is conveniently described in terms of a phenomenological interface mobility. Measuring the velocity of the hydration front relative to the lattice of the reactant periclase, the temperature dependence of its mobility is described by an Arrhenius relation with pre-exponential factor 1.7.10−12 m 4/s.J and activation energy of E A =55 kJ/mol.

Organisation(s)
Department of Lithospheric Research
External organisation(s)
Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum
Journal
Mineralogy and Petrology
Volume
110
Pages
1-10
No. of pages
10
ISSN
0930-0708
DOI
https://doi.org/10.1007/s00710-015-0414-2
Publication date
12-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
105116 Mineralogy, 105120 Petrology
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/hydration-of-periclase-at-350-degrees-c-to-620-degrees-c-and-200-mpa(3d99e49d-90bd-4b8e-8b48-ea697357650c).html