Hydrothermal reaction of silica sand contains some impurities with lime

Osamu Watanabe, E. Hideki Ishida

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Tobermorite and xonotolite are the representative of calcium silicate materials and many studies have been made in the past regarding the methods of synthesis from relatively highly purified starting materials. From the point of preserving the global environment, procurement of pure raw materials for industrial use is likely to become difficult in the future, and the recycled use of various waste materials cannot be avoided. The hydrothermal reaction of slaked lime and silica sand containing feldspar and clay minerals as impurities have investigated. It was found that the flexural strength of the solidified bodies increased with increasing treatment temperature and treatment time, reaching values of up to 20MPa which was enough for building material and was proportional to the amount of reaction products but independent of their type. Hydrogarnet and C-S-H were formed in the initial stages of reaction and the amount of these phases tended to decrease and 1.1 nm tobermorite formed as the reaction progressed further. This indicates that hydrogarnet and C-S-H are precursors of 1.1 nm tobermorite. In this hydrothermal process, it was clarified that the reaction was controlled by the diffusion of Si fraction from kinetic study.

Original languageEnglish
Title of host publicationWATER DYNAMICS
Subtitle of host publication3rd International Workshop on Water Dynamics
Number of pages6
Publication statusPublished - 2006 May 15
Externally publishedYes
EventWATER DYANMICS: 3rd International Workshop on Water Dynamics - Sendai, Japan
Duration: 2005 Nov 162005 Nov 17

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherWATER DYANMICS: 3rd International Workshop on Water Dynamics


  • C-S-H
  • Clay minerals
  • Diffusion
  • Feldspar
  • Hydrogarnet
  • Hydrothermal reaction
  • Silica sand
  • Tobermorite

ASJC Scopus subject areas

  • Physics and Astronomy(all)


Dive into the research topics of 'Hydrothermal reaction of silica sand contains some impurities with lime'. Together they form a unique fingerprint.

Cite this