Ca7ZrAl6O18 acting as a hydraulic and ceramic bonding in the MgO-CaZrO3 dense refractory composite

In this paper, the results of an experimental study concerning the dehydration behavior of the hydrated MgO-CaZrO3-Ca7ZrAl6O18 green compacted sample are presented. Hydrated MgO-CaZrO3-Ca7ZrAl6O18 mixture products were studied by XRD, DTA-TG and FT-IR after 24 h of curing and hydration at room temperature. According to the XRD examination it has been found that brucite, Mg(OH)(2), was only identified as a crystalline hydrated phase. The presence of the metastable hexagonal hydrates (CAH(10), C(2)AH(8)) in the hydrated sample were identified by FT-IR and DTA-TG studies. The MgO-CaZrO3-aluminates dense refractory composite material was investigated by XRD, SEM/EDS and mercury porosimetry. The XRD and SEM/EDS results showed that the compound with chemical composition of Ca12Al14O33 occurred in the MgO-CaZrO3-Ca7ZrAl6O18 matrix. By applying the mercury intrusion porosimetry technique, the heterogeneous pore size distribution of the composite was determined. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.