Analysis of the isothermal crystallization of CaSiO3 in a CaO-Al2O3-SiO2 melt through in situ observations

Crystal growth of Wollastonite (CaO center dot SiO2) in a 42CaO-10Al(2)O(3)-48SiO(2) melt is observed in situ at 1320 degrees C and 1370 degrees C using a high-temperature confocal scanning laser microscope (CSLM). The crystallization is initiated by seeding the melt with Wollastonite particles, which is the primary phase at these temperatures and composition. At 1370 degrees C, a faceted growth form is observed, while at 1320 degrees C, dendritic, non-faceted growth occurs. The dendrite tip velocity is measured and compared with Ivantsov's theory. The presented experimental technique proofs to be successful for characterizing isothermal crystallization of minerals in silicate melts. (C) 2011 Elsevier Ltd. All rights reserved.