https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:12253 2. We demonstrate the optimization of heat treatment of antigorite, providing a benchmark of an extreme case of activation among serpentine minerals. Antigorite was investigated non-isothermally via thermogravimetry-mass spectrometry and in situ X-ray powder diffraction, its thermal reaction sequence elucidated, and reaction kinetics subsequently modeled. Based on the thermally induced structural changes, preferred content of residual hydroxyls in the dehydroxylated antigorite amounts to 10–40% of those present initially. This degree of dehydroxylation minimized the transformation of antigorite into new crystalline phases maximizing the amorphization of the new structure. The thermal reaction sequence provided both the explanation for the observed kinetic behavior and the basis for this optimization strategy. The optimal time for heat activation corresponds to ≤30 min, including the heat-up period at a rate of 30 °C min^–1 and an isothermal stage at 730 °C. This was successfully modeled using a three-dimensional phase boundary reaction model (R3), with activation energy E_a of 160 kJ mol^–1 and a frequency factor A of 5.7 ± 4.1 × 10⁵ s^–1 (5.7 × 10⁵ s^–1 for dynamic and 1.6 × 10⁵ s^–1 for static stage). This strategy translates to a fast and efficient thermal processing in an optimally sized calcining vessel. Furthermore, these results imply that activation of the more common serpentine minerals lizardite and chrysotile would be significantly faster as their dehydroxylation proceeds at lower temperatures than that of antigorite.]]> Sat 24 Mar 2018 08:08:10 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21467 Sat 24 Mar 2018 07:52:31 AEDT ]]>