Ferrous Oxide Activity in FeO-TiO2-CaO-Al2O3 System.

Abstract

BoxFerrous oxide activity has been determined in molten synthetic slag mixtures of the quaternary system FeO-TiO.-CaO-AI.03 at constant levels of Al,03' Furthermore, in the course of determining the FeO activity in this quaternary system, the ternary system FeO-CaO-AI=0, was also investigated at 1 450'C.The technique used to measure the ferrous oxide activity in the investigated systems was the well established one of gas-slag-metal equilibration in which molten slags contained in armco iron crucibles are exposed to a flowing gas mixture with a known oxygen potential until equilibrium has been attained.After equilibration, the final chemical analysis of the slags give compositions having a particular ferrous oxide activity corresponding to the oxygen potential of the gas mixture.The effect of Al,O, additions on the FeO activity was determined. The results are presented as a series of iso-activity curves on pseudo-ternary diagrams. The interdependence between the ferrous oxide activities and slag composition was also studied.

Sulfur concentration at sulfide saturation (SCSS) in magmatic silicate melts

“…Divalent iron has the highest electronegativity value, 1.65 (Fyfe, 1964), among all the major network-modifier cations (Mg, Ca, Fe, Na, and K) in silicate melts and the empty d orbitals of divalent iron favor its bonding to S 2À more readily than other ions lacking d orbitals, or with filled d orbitals (Fyfe, 1964). However, the activity of divalent iron is affected by the other components in the silicate melt, and the possible formation of melt species involving sulfur and cations other than iron cannot be eliminated (Eissa et al, 1996;O'Neill and Mavrogenes, 2002). Therefore, concentrations of all cations in the melt influence sulfur solubility, rather than only that of Fe.…”

Conversion of Mill Scale Waste into Valuable Products via Carbothermic Reduction

“…Increase of the reducing agent amount leads to decreasing slag iron oxide content and increasing metal carbon content. The activity of the oxygen in the melt is directly proportional to the slag iron oxide content [12]. Therefore, low activity of oxygen in the metal is expected leading to appropriate conditions for the removal of the sulphur and desulphurization of the metal, as it is indicated from (8).…”

Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags

“…According to (2), the value of P e is equal to 9.267 × 10 −16 Pa at 1 673 K, it is very small compared to P O2 . So (1) can be simplified as…”