Synthesis of a Diatomite-Based Calcium Metasilicate Hydrate and Investigation of Its Adsorptive and Structural Properties

Optimal conditions have been found for lime treatment of diatomite from the Jradzor deposit (Armenia) which ensure that the resulting calcium metasilicate hydrate has a large specific surface area, high adsorption capacity, and good filtration performance. Differential thermal analysis, IR spectroscopy, and X-ray diffraction have been used to identify the mechanism underlying the formation of a C–S–H(I) calcium metasilicate hydrate during lime treatment of diatomite. Water and benzene vapor adsorption isotherms have been used to assess adsorptive and structural properties of the C–S–H(I) calcium metasilicate hydrate and calculate parameters of its pore structure. It is shown that C–S–H(I) calcium metasilicate hydrate can be effectively used as a filtration material and adsorbent.