Abstract
The swelling of sericite by a LiNO3 hydrothermal treatment and the effect of dehydroxylation of sericite prior to hydrothermal treatment are investigated in this study. We demonstrate that a well-swelled sericite with 80% exchangeable K and a cation exchange capacity of 1.10 meq/g can be prepared from a fully dehydroxylated sample under 270 °C hydrothermal treatment. Some Li+ ions were found to permanently migrate into the sericite but without a total charge reduction of sericite after hydrothermal treatment. Accordingly, some octahedral hydroxyls transform into "-OLi" forms, a transformation that may be promoted by dehydroxylation. The hydrothermal treatment reconstitutes the hydroxyl groups of sericite lost during dehydroxylation. However, OH groups of pyrophyllite released during dehydroxylation are not regained after hydrothermal treatment. Finally, the pyrophyllite in the original sericite ore is not affected during hydrothermal treatment. Consequently, pure sericite particles in hydrothermally treated sericite ore can be easily separated from pyrophyllite particles by hydrodynamic sedimentation due to the selective swelling of sericite.
| Original language | English |
|---|---|
| Pages (from-to) | 282-288 |
| Number of pages | 7 |
| Journal | Applied Clay Science |
| Volume | 43 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2009 Feb 1 |
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All Science Journal Classification (ASJC) codes
- Geology
- Geochemistry and Petrology
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Swelling of sericite by LiNO3-hydrothermal treatment. / Shih, Yu Jen; Shen, Yun-Hwei.
In: Applied Clay Science, Vol. 43, No. 2, 01.02.2009, p. 282-288.Research output: Contribution to journal › Article
TY - JOUR
T1 - Swelling of sericite by LiNO3-hydrothermal treatment
AU - Shih, Yu Jen
AU - Shen, Yun-Hwei
PY - 2009/2/1
Y1 - 2009/2/1
N2 - The swelling of sericite by a LiNO3 hydrothermal treatment and the effect of dehydroxylation of sericite prior to hydrothermal treatment are investigated in this study. We demonstrate that a well-swelled sericite with 80% exchangeable K and a cation exchange capacity of 1.10 meq/g can be prepared from a fully dehydroxylated sample under 270 °C hydrothermal treatment. Some Li+ ions were found to permanently migrate into the sericite but without a total charge reduction of sericite after hydrothermal treatment. Accordingly, some octahedral hydroxyls transform into "-OLi" forms, a transformation that may be promoted by dehydroxylation. The hydrothermal treatment reconstitutes the hydroxyl groups of sericite lost during dehydroxylation. However, OH groups of pyrophyllite released during dehydroxylation are not regained after hydrothermal treatment. Finally, the pyrophyllite in the original sericite ore is not affected during hydrothermal treatment. Consequently, pure sericite particles in hydrothermally treated sericite ore can be easily separated from pyrophyllite particles by hydrodynamic sedimentation due to the selective swelling of sericite.
AB - The swelling of sericite by a LiNO3 hydrothermal treatment and the effect of dehydroxylation of sericite prior to hydrothermal treatment are investigated in this study. We demonstrate that a well-swelled sericite with 80% exchangeable K and a cation exchange capacity of 1.10 meq/g can be prepared from a fully dehydroxylated sample under 270 °C hydrothermal treatment. Some Li+ ions were found to permanently migrate into the sericite but without a total charge reduction of sericite after hydrothermal treatment. Accordingly, some octahedral hydroxyls transform into "-OLi" forms, a transformation that may be promoted by dehydroxylation. The hydrothermal treatment reconstitutes the hydroxyl groups of sericite lost during dehydroxylation. However, OH groups of pyrophyllite released during dehydroxylation are not regained after hydrothermal treatment. Finally, the pyrophyllite in the original sericite ore is not affected during hydrothermal treatment. Consequently, pure sericite particles in hydrothermally treated sericite ore can be easily separated from pyrophyllite particles by hydrodynamic sedimentation due to the selective swelling of sericite.
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UR - http://www.scopus.com/inward/citedby.url?scp=58249142298&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2008.09.006
DO - 10.1016/j.clay.2008.09.006
M3 - Article
VL - 43
SP - 282
EP - 288
JO - Applied Clay Science
JF - Applied Clay Science
SN - 0169-1317
IS - 2
ER -