Abstract: The crystals of hydrated silicates which were formed with pressure-steam were studied by using the scanning electron microscope, X-ray diffractometer, Fourier transformation infrared spectrometer and thermoanalyzer. According to the measurements, their structure characteristics were investigated, and the mechanisms for the formation were discussed in detail.
It was found from experiments that under the pressure-steam condition, the amorphous quartz and the crystalline quartz reacting with Ca(OH)₂ would mainly come to be Xonotlite and Tobermorite respectively. These reactions were able to explain the mechanism of hydrated crystals and the diffusing mechanism through the lattice, respectively. If he amorphous quartz and crystalline quartz existed together, the former reacted with Ca(OH)₂ at a higher rate than the latter, and the product was mainly Xonotlite.