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Thermal Behavior and Determination of the Heated Structure of 11Å Anomalous Tobermorite by in situ X‐ray Diffraction
Author(s) -
YAN Yu,
WANG Hejing
Publication year - 2021
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.14678
Subject(s) - tobermorite , wollastonite , materials science , lime , calcite , crystallography , scanning electron microscope , mineralogy , quartz , diffraction , transmission electron microscopy , analytical chemistry (journal) , composite material , chemistry , nanotechnology , metallurgy , cement , optics , raw material , physics , organic chemistry , chromatography
This article presents the thermal transitions of a tobermorite‐bearing sample when heated from 30°C up to 1200° C, both in vacuum and in static air, including tobermorite transforming to wollastonite, aragonite to calcite and calcite to lime. Characteristics obtained by in situ high temperature X‐ray diffraction, field emission scanning electron microscopy and scanning transmission electron microscopy analyses jointly indicate that the investigated tobermorite is anomalous. The variations along the a , b , c axes and the volume changes of tobermorite with increasing temperature are described, and its thermal shrinkage coefficients therefore determined. The comparison between the refined structures at 30°C and 800°C demonstrates that the shrinkage degree (Δ a / a 0 ) along the a axis is higher than those (Δ b / b 0 , Δ c / c 0 ) along the b and c axes. The wollastonite is formed in two ways: Tobermorite converting to wollastonite and lime reacting with quartz to form wollastonite.