Hillebrandite partially dehydrates in two steps at 422 and 508[degrees]C and transforms to [gamma]-[C.
Hillebrandite was synthesized by hydrothermal treatment of quartz and lime with Ca/Si = 2.
2]S depends on calcination temperature of hillebrandite.
Preparation of hillebrandite by hydrothermal treatment of silica fume and lime with and without 2wt% Ba[Cl.
2]S was carried out by calcination of hillebrandite in an electric muffle furnace at 600 or 700[degrees]C for 3 hours.
FTIR indicates that the chance of formation hillebrandite was improved by increase of both time (Figure 5) and temperature (Figure 6) of hydrothermal treatment.
Hillebrandite lost absorbed water at 109[degrees]C.
As determined by TGA/DTA results, hillebrandite completely dehydrates forming [alpha]'-[C.
Hillebrandite does not appear in the XRD analysis (Figure 9(a)) because of its gel structure.
The mixtures of silica fume and lime that were hydrothermally treated at 110[degrees]C for 2 hours contain little amount of hillebrandite of low density with web-like morphology (Figures 11(a) and 11(b)).
1) FTIR results show that hillebrandite was successfully prepared by hydrothermal treatment of lime/silica fume mixtures with (Ca + Ba)/Si = 2 at 110[degrees]C for 5 hours.