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In situ synchrotron powder diffraction study of active belite clinkers
Author(s) -
De la Torre Ángeles G.,
Morsli Khadija,
Zahir Mohammed,
Aranda Miguel A.G.
Publication year - 2007
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889807042379
Subject(s) - belite , powder diffraction , materials science , rietveld refinement , crystallography , phase (matter) , synchrotron , silicate , atmospheric temperature range , mineralogy , analytical chemistry (journal) , chemistry , crystal structure , metallurgy , clinker (cement) , cement , physics , thermodynamics , portland cement , organic chemistry , chromatography , nuclear physics
The clinkerization processes to form belite clinkers, with theoretical compositions close to 60 wt% of Ca 2 SiO 4 , have been studied in situ by high‐resolution high‐energy (λ = 0.30 Å) synchrotron X‐ray powder diffraction. In order to obtain active belite cements, different amounts of K 2 O, Na 2 O and SO 3 have been added. The existence range of the high‐temperature phases has been established and, furthermore, Rietveld quantitative phase analyses at high temperature have been performed for all patterns. The following high‐temperature reactions have been investigated: (i) polymorphic transformations of dicalcium silicate, ‐Ca 2 SiO 4 ↔‐Ca 2 SiO 4 from 1170 to 1230 K, and ‐Ca 2 SiO 4 ↔α‐Ca 2 SiO 4 from 1500 to 1600 K; (ii) melting of the aluminates phases, Ca 3 Al 2 O 6 and Ca 4 (Al 2 Fe 2 )O 10 , above ∼1570 K; and (iii) reaction of Ca 2 SiO 4 with CaO to yield Ca 3 SiO 5 above ∼1550 K. Moreover, in all the studied compositions the temperature of the polymorphic transformation ‐Ca 2 SiO 4 ↔α‐Ca 2 SiO 4 has decreased with the addition of activators. Finally, active belite clinkers were produced as the final samples contained α‐belite phases.