Calcium Aluminates

By fusion of calcium oxide or calcium carbonate with aluminium oxide a number of aluminates can be obtained. The chemical individuality of four of these seems to be definitely established, 3CaO.Al₂O₃, 5CaO.3Al₂O₃, CaO.Al₂O₃, and 3CaO.5Al₂O₃. The possibility of the formation of the compounds, 2CaO.Al₂O₃, 3CaO.2Al₂O₃, 6CaO.5Al₂O₃, and 11CaO.10Al₂O₃, has also been suggested, but they have not been thoroughly investigated, and it is probable that some or all of them are solid solutions.