A quaternary phase isostructural with alpha-Fe1-xSi2 and named `'caalsifer" for its chemical constitution was earlier detected in industrial ferrosilicon alloys (Margarido and Figueiredo, 1988). With the aim of ascertaining the possible domain for such a non-equilibrium compound and contributing to the understanding of microstructure and phase solidification in casting processes of ferrosilicon alloys, a systematic study of phase formation within the quaternary Fe-Si-Al-Ca system was undertaken. Results are presented of laboratory experiments using both are and induction fusion furnavces with water-cooled copper crucibles, and compositions close to that assumed for cadsifer. The obtained materials were chemically and compositionally characterized through scanning electron microscopy and X-ray diffraction. A relation is tentatively established between microstructure plus phase assemblage on the one hand, and cooling rate on the other.