ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Densities of melts in the system CaO-FeO-Fe₂O₃-SiO₂

T. Ličko, V. Daněk, and Z. Pánek

Institute of Inorganic Chemistry, Centre for Chemical Research, Slovak Academy of Sciences, CS-842 36 Bratislava

Abstract: The densities of melts in the system CaO—FeO—Fe₂O₃—SiO₂ in air were measured in the temperature range 1540—1910 K. The densities of the investigated melts increase with the increasing content of the iron oxides. The change of the oxidation state of iron with temperature results in nonlinear dependence of density on the temperature and in the decrease of the molar volume of the melts with the increasing temperature. The system CaO—FeO—Fe₂O₃—SiO₂ is nonideal. From the dependences of the partial molar volumes of Fe₂O₃ and SiO₂ on the composition it can be assumed that a part of the Fe(III) atoms is coordinated tetrahedrically, i.e. it behaves as a network former. The formal negative charge on the iron in the FeO₄ tetrahedron can be compensated with the Ca ²⁺ or Fe²⁺ or Fe³⁺ cations, respectively. The entrance of Fe³⁺  into the polyanionic network is accompanied by the volume contrac­ tion.

Full paper in Portable Document Format: 395a599.pdf

Chemical Papers 39 (5) 599–605 (1985)