Data on the binary system 3CaO.Al2O3-Na2O.8CaO.3 Al2O3 within the system CaO-Al2O3-Na2O

Abstract

Summary Conwicke and Day showed that partial solid solution occurs in the system C₃A-NC₈A₃ at temperatures below the liquidus. Their results indicated a marked similarity between the X-ray powder diffraction data for a preparation containing more than 3·0% Na₂O and the data given by Moore for a new phase in Portland cements. The present work was almost complete when Conwicke and Day's paper was published. It generally confirms their results but gives more information on the solid solution. At the limit of solid solution at 1,350°C the sodium calcium aluminate which is formed has the composition 91·0 mol % C₃A, 9·0 mol % N₃A and has been indexed on an orthorhombic unit cell with a = 15·314, b = 15·394, c = 15·137 Å.