Synthesis of kaolinite from micas and K-depleted micas

Yunchul Cho, Sridhar Komarneni

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

The weathering stages of K-depleted biotite, K-depleted phlogopite, and natural biotite were investigated using hydrothermal treatment with AlCl3 solution at 200°C for 12 to 72 h. Although there were some differences in the degree of weathering of the two K-depleted micas, both first transformed to hydroxy-Al interlayered vermiculite (HIV), which then altered to kaolinite. In case of the natural biotite, the biotite first transformed to a K-depleted mica-like phase, which then altered to kaolinite. The natural biotite had resisted weathering to kaolinite more than did the K-depleted biotite, as expected. The K-depleted phlogopite had less resistance in weathering to kaolinite than the K-depleted biotite. The transformation process changed the color of the micas. The K-depleted biotite changed from greenish-black through yellow to pale gray whereas the natural biotite changed from greenish-black through beige to yellow. However, in the case of K-depleted phlogopite, there was no significant color change during the transformation process. The presence of the interlayer K+ ions and the structural Fe2+ ions in mica appear to have contributed to the differences in the degree of weathering to kaolinite among the micas investigated.

Original languageEnglish (US)
Pages (from-to)565-571
Number of pages7
JournalClays and Clay Minerals
Volume55
Issue number6
DOIs
StatePublished - Dec 1 2007

All Science Journal Classification (ASJC) codes

  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)

Fingerprint Dive into the research topics of 'Synthesis of kaolinite from micas and K-depleted micas'. Together they form a unique fingerprint.

  • Cite this