Phase diagram for the system CaO-Al2O3-ZrO2

Abstract

Phase equilibria in the system CaO-Al 2 O 3 -ZrO 2 were studied to optimize nozzle composition for tundishes that are used in continuous casters of steel, by identifying the composition that minimizes clogging. Mixtures of CaO, Al 2 O 3 , and ZrO 2 with various compositions were equilibrated at 1873 and 1773 K and then quenched into water. X-ray diffraction analysis was used for phase identification, and electron probe microanalysis was employed to measure chemical compositions. On the basis of these and previous results, the eutectic and peritectic lines have been estimated. Based on the phase diagram, the optimal nozzle composition is CaO-saturated CaZrO 3 .1. The compositions of single-phase regions are experimen-

Relationship between the Aluminum and Oxygen and Sulfur Partitions for Molten Iron and a CaO-Al2O3-ZrO2 Slag in Equilibrium

“…Oxide activities in the CaO-Al 2 O 3 -ZrO 2 system were measured only for the CaO-Al 2 O 3 5) and CaO-ZrO 2 systems. 6) Phase diagrams of the CaO-Al 2 O 3 -ZrO 2 system were reported by Berezhnoi et al, 7) Espinosa et al, 8) Bannister, 9) Kisida et al, 10) Sakai et al 11) and Murakami et al 12) Nurse et al 13) established the CaO-Al 2 O 3 system. The Al 2 O 3 -ZrO 2 system was summarized in the Slag Atlas.…”

Solubility of Calcium and Oxygen in Molten Iron Equilibrated with Slag in CaO, Al2O3 or CaO-stabilized ZrO2 Crucible at 1873 K

“…The intensity of XRD peaks of 3CaO·Al2O3 is stronger than the others. From the CaO-Al2O3-ZrO2 phase diagram 7) as shown in Fig. 1, 3CaO·Al2O3 decomposes at 1 873 K and the molten slag is equilibrated with CaO·ZrO2 and CaO.…”

“…According to the ternary phase diagram of CaO-Al2O3-ZrO2 system as shown in Fig. 1 determined by Murakami et al, 7) the slag in a CaO crucible is equilibrated with CaO and CaO·ZrO2 compound, that in an Al2O3 crucible is equilibrated with CaO·2Al2O3 compound and ZrO2-CaO solid solution (Css) and that in a CaO-stabilized ZrO2 crucible is equilibrated with ZrO2-CaO solid solution (Css) and CaO·ZrO2 compound. Nagata et al 8) measured the activity of CaO in CaO-Al2O3 system and Tanabe et al 9) measured it in CaO-ZrO2 system by mean of an electrochemical method.…”

Smelting of Metallic Titanium from an Oxide Flux Using a CaO-Stabilized ZrO₂ Solid-Electrolyte Electrode

“…The CaO-Al 2 O 3 -ZrO 2 ternary system 15) contains compositions with lower melting temperatures than metallic titanium and is constituted exclusively of metallic oxides with higher oxygen affinity than titanium oxide, according to the Gibbs free energy. Thus, this system satisfies the requirements for the flux in the smelting reduction process.…”

“…A flux composition was selected in the CaO-Al 2 O 3 -ZrO 2 ternary system, 15) whose constituent metallic oxides have high oxygen affinity. This flux can be equilibrated with the CaO-stabilized ZrO 2 solid electrolyte at a suitable composition.…”