Formation Mechanism of Gehlenite-Anorthite Materials Containing ZrO2 from Andalusite, CaCO3 and ZrO2
This paper reports the results of using natural andalusite (Al2SiO5) in combination with CaCO3 and ZrO2 in order to obtain aluminosilicate product. This work was devoted to the study of the mechanism of new phases creation in the Al2SiO5-CaO-ZrO2 phase system during heating at different temperatures (1000, 1100, 1200, 1300 and 1400°C). Al2SiO5, CaCO3, and ZrO2 were used in a weight ratio of 45:50:5, respectively. According to the phase composition and chemical analysis in microareas, it was found, that andalusite reacted with CaO giving two calcium aluminosilicates: gehlenite and anorthite at 1400°C. ZrO2 was presented as the separated phase at this temperature. Other occurring transition phases were: CaZrO3 at 1000 and 1200°C, Ca2SiO4 at 1000, 1100 and 1200°C, Ca3ZrSi2O9 at 1300°C. The synthesis mostly depended on the diffusion of Ca2+ ions.
Gundars Mežinskis, Līga Grase, Ruta Švinka, Ilona Pavlovska, Jānis Grabis, Kęstutis Baltakys and Irina Hussainova
E. Śnieżek et al., "Formation Mechanism of Gehlenite-Anorthite Materials Containing ZrO2 from Andalusite, CaCO3 and ZrO2", Key Engineering Materials, Vol. 788, pp. 120-125, 2018