Hydrothermal transformation of mixed metal oxides and silicate anions to phyllosilicate under highly alkaline conditions

Qi Tao, Manyou Chen, Hongping He, Sridhar Komarneni

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Mixed metal oxides (MMO) were transformed to phyllosilicate in the presence of silicate anions under hydrothermal conditions. The product was shown to be saponite with a trioctahedral layer structure by characterization with XRD, FTIR, 27Al and 29Si MAS NMR, HRTEM and TG-DTG. The formation of saponite was through a rehydration-dissolution-precipitation pathway, involving the critical steps such as the reconstruction of MMO to hydrotalcite (Ht), exsolution of Al3+ from Ht, condensation of metasilicate anions with Ht, and finally crystallization of saponite. Isomorphous substitution of Al3+ for Si4+ in silicate oligomers is the key for the above conversion, which generated the negative charge necessary for the condensation between the silicate oligomers and Ht surface and the formation of 2:1 saponite TOT layers. High pH value (over 14.0) favored the condensation of silicate oligomers and led to crystallization of saponite. Thus, we report a novel method for the crystallization of saponite.

Original languageEnglish (US)
Pages (from-to)224-230
Number of pages7
JournalApplied Clay Science
Volume156
DOIs
StatePublished - May 1 2018

All Science Journal Classification (ASJC) codes

  • Geology
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Hydrothermal transformation of mixed metal oxides and silicate anions to phyllosilicate under highly alkaline conditions'. Together they form a unique fingerprint.

Cite this