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Studies on Formation and Recrystallization of Intermediate Reaction Products in the System Magnesia‐Silica‐Water
Author(s) -
KALOUSEK GEORGE L.,
MUI DANIEL
Publication year - 1954
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1954.tb14001.x
Subject(s) - talc , differential thermal analysis , mineralogy , raw material , silicic acid , recrystallization (geology) , magnesium , materials science , chrysotile , chemistry , chemical engineering , metallurgy , organic chemistry , diffraction , geology , paleontology , physics , engineering , asbestos , optics
Mixtures of magnesia and silicic acid ranging in composition from 0.5 to 2.0 M/S were treated hydrothermally at temperatures of 75° to 350°C. for various periods of time. The reaction solids were examined by differential thermal analysis, X ray, and electron microscopy and analyzed chemically. The intermediate products of reaction ranging in composition between that of talc (0.75 M/S) and chrysotile (1.5 M/S) comprised a continuous series of cryptocrystalline needle‐like crystaIs matted tightly together and showing the same X‐ray pattern. The initial reaction product of the 0.75 to 1.50 M/S raw mixtures was a cryptocrystalline solid having a 1.5 M/S ratio. This phase subsequently reacted with the residual silica, so long as any was available, to form a solid having the composition of the raw mix, but only at relatively moderate temperatures(100°to175°C.). As the temperature was increased the crystals of the 0.75 and 1.50 M/S compositions increased in size, but all remained submicroscopic. The compositions intermediate between 0.75 and 1.5 M/S crystallized as mixtures of talc and chrysotilelike products. The chrysotilelike product appeared as minute needles which did not possess any apparent flexibility.