FORMATION OF GYROLITE DURING HYDROTHERMAL SYNTHESIS IN THE MIXTURES OF CAO AND AMORPHOUS SIO2 OR QUARTZ

Gyrolite, a calcium silicate hydrate, rarely occurs as a natural mineral in association with zeolites as a low-temperature hydrothermal replacement product of basic igneous rock. Synthetic gyrolite was hydrothermally created in the late 1930s. This article reports on parameters of gyrolite hydrothermal synthesis that were determined when primary mixtures consisting CaO and amorphous SiO2-nH2O or quartz and a sequence of intermediary compound formation were examined and explained. Hydrothermal synthesis was carried out in saturated steam at 150, 175, and 200 deg C temperatures. The duration of isothermal curing was 4, 16, 24, 32, 48, 72, and 168 h. Results showed that gyrolite does not form even after a week in the mixtures of CaO and amorphous SiO2 at 150 deg C temperature in saturated steam. Increase in the temperature positively affects the synthesis of this compound. The authors note that while synthesizing gyrolite, intermediary compounds C-S-H (I) and Z-phase are always formed. The authors conclude that the mechanism of hydrothermal reactions and a sequence of compounds to be formed in CaO mixtures with quartz are quite different. Experimentally obtained data and preconditions are verified by thermodynamic calculations.

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    Elsevier

    The Boulevard, Langford Lane
    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • Siauciunas, R
    • Baltakys, K
  • Publication Date: 2004-11

Language

  • English

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  • Accession Number: 00986435
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 8 2005 12:00AM