Densification Process of Sepiolite under Hydrothermal Hot-pressing

Abstract

Hydrothermal hot-pressing method was applied for sintering fibrous clay mineral; sepiolite. Densification process was analyzed by shrinkage measurements during the treatments. Hot-pressed samples were studied by XRD, BET surface area, pore size distribution, and compressive strength measurements. The densification was proceeded by two steps; rearrangement of sepiolite fibers, followed by transforming to smectite at surface. Although specific surface area was not decreased significantly, pore size distribution was remarkably changed. The sample was elastically compressed with 990 MPa of elastic modulus, and 15% of elastic deformation. It was concluded that the hydrothermal hot-pressed sepiolite was useful not only for adsorbents but also for a new inorganic elastomer.