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HETEROGENEITY IN SILICON‐IRON MIXED HYDROXIDES
Author(s) -
HERBILLON A. J.,
VINH AN J. TRAN
Publication year - 1969
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1969.tb01569.x
Subject(s) - precipitation , ferric , phase (matter) , silicon , amorphous solid , silica gel , spectroscopy , chemistry , analytical chemistry (journal) , materials science , inorganic chemistry , mineralogy , nuclear chemistry , crystallography , metallurgy , chromatography , organic chemistry , physics , quantum mechanics , meteorology
Summary Several mixed hydroxides obtained by co‐precipitation of FeCl 2 or FeCl 2 with Na 2 SiO 2 followed by ageing and purification were studied by X‐ray diffraction, infra‐red spectroscopy, and surface‐area measurements. The compounds with molecular ratios SiO 2 /Fe 2 O 3 ranging from 0·1 to 1·17 are essentially amorphous. Silica, which is not to be considered as an integral part of the gel, is chemi‐sorbed on the ferric or‘ferrosic’ phase. The good agreement between IR, DTA, and surface‐area measurements with increasing molecular ratios permits the distinction between two ranges of silica contents. In the first range, MR <·1, silica is directly chemisorbed on the adsorbant. In the MR >0·1 range, silica polymerizes as a separate phase growing upon the‘ferrosic’ or‘ferric’ phase.