Journal
CLAY MINERALS
Volume 48, Issue 5, Pages 687-696Publisher
MINERALOGICAL SOC
DOI: 10.1180/claymin.2013.048.5.22
Keywords
saponite; stevensite; hectorite; mixed-layer hectorite/stevensite; XRD; identification; heating; Cs-saturation; glycerol solvation
Ask authors/readers for more resources
A new method for identifying the trioctahedral smectites saponite, stevensite and hectorite is proposed in this study. The method is based on differences in the X-ray diffraction (XRD) patterns of the three smectites after (a) heating at 500 degrees C for 90 min and (b) glycerol solvation of the Cs-forms of the smectites for 20 h. After heating at 500 degrees C, well below the dehydroxylation temperature of the three smectites, saponite and hectorite re-expand upon ethylene glycol (EG) solvation, whereas stevensite layers remain collapsed. Saponite forms one-layer and hectorite two-layer complexes after Cs-saturation and glycerol solvation. Cs-stevensite displays a gradual increase in d(001) with increasing solvation time in glycerol vapours and forms two-layer glycerol complexes with prolonged solvation. Except for the individual Mg-smectites, the proposed method may be used to identify compositional heterogeneity that may exist in the smectites. Furthermore, it should be useful in identifying the individual trioctahedral Mg-smectites when present in mixtures, and in detecting interstratified layers of different Mg-trioctahedral smectites. Application of the method revealed that the SYnL-1 laponite (CMS Source Clay Project) is not homogeneous but consists of hectorite, stevensite and possibly mixed-layer hectorite/stevensite layers.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available