Critical Assessment and Thermodynamic Modeling of the Fe-O-S System

Abstract

The Fe-O-S system has been assessed over the whole composition range to produce a selfconsistent set of thermodynamic properties of all condensed phases from 298 K to above the liquidus temperatures at ambient pressure. The liquid phase from metallic liquid to sulfide melt to oxide melt is described by a single model developed within the framework of the quasichemical formalism. The model reflects the existence of strong short-range ordering in oxide, sulfide and oxysulfide liquid. Two ranges of maximum short-range ordering in the Fe-O system at approximately FeO and Fe 2 O 3 compositions are taken into account. Parameters of thermodynamic models have been optimized to reproduce all available thermodynamic and phase equilibrium data. The thermodynamic modeling of the Fe-O-S system performed in the present study is of particular importance for the description of the solubility of oxygen in matte.

Integrated Experimental and Thermodynamic Modeling Study of the Effects of Al2O3, CaO, and MgO on Slag–Matte Equilibria in the Cu-Fe-O-S-Si-(Al, Ca, Mg) System

“…Liquid matte/metal (Fe II , Fe III , Cu I , Cu II , O II , S II ), MQMPA [14,18,23,[28][29][30][31][32] Pyrrhotite (Fe, Cu, Vacancy)S, BW [28,30] Digenite-bornite (Cu 2 , Fe, Vacancy)S, BW [29] Intermediate solid sulfide solution (Cu 2 , Fe, Vacancy)S, BW [29] Metallic phases fcc-Cu and fcc-Fe (Fe, Cu, O, S), BW [14,18,23] bcc-Fe (Fe, Cu, O, S), BW [23] Sulfate phases [14,31,32] BW Bragg-Williams model, CEF compound energy formalism, MQMQA modified quasichemical model in the quadruplet approximation, MQMPA modified quasichemical model in the pair approximation experimental methodology based on phase composition measurements by microanalysis techniques. 4.…”

“…A thermodynamic assessment of a multi-component chemical system involves undertaking thermodynamic optimizations of all subsystems. All subsystems of the 5-component Cu-Fe-O-S-Si system have been assessed and the results have been published for the following subsystems: Fe-O, [23] Cu-S, Fe-S, Cu-Fe-S, [28][29][30] Cu-O and Cu-O-S, [14] Cu-Fe-O, [18] Fe-O-S, [31] Cu-Fe-O-S, [32] Cu-O-Si, [27] Fe-O-Si, [20] Cu-Fe-O-Si, [19] Fe-O-S-Si and Cu-Fe-O-S-Si. [1] Furthermore, the Al 2 O 3 -, MgO-and CaO-containing subsystems were assessed in the following studies: Al-Fe-O, [24] Al-O-Si, [15] Al-Fe-O-Si, [34,35] Al-Cu-O and Al-Cu-O-Si, [36] Fe-Mg-O, [26] Mg-O-Si, [37] Fe-Mg-O-Si, [21] Cu-Mg-O and Cu-Mg-O-Si, [36] Ca-Fe-O, [22] Ca-Fe-O-Si, [16] Ca-Cu-O and Ca-Cu-O-Si, [27] Ca-Cu-Fe-O.…”

Thermodynamic database for multicomponent oxide systems

“…This assumption greatly simplifies the model, increasing its predictive ability. The dissolution of excess metal in oxide liquid that may take place at very high temperatures solutions at 1600 °C based on the thermodynamic assessments of the corresponding systems: Fe-O [57], Ni-Fe [58], Ni-Al [59], NaO 0.5 -SiO 2 [60] and NaO 0.5 -BO 1.5 [61]. The enthalpies of mixing for the latter two systems are shown per mole of cations is not important for most practical applications of the oxide database.…”

Experimental Study and Thermodynamic Re-optimization of the FeO-Fe2O3-SiO2 System

“…The liquid iron solution was described using an Associate Model with Fe and O as the components. Previously optimized parameters for the solid metallic phases (fcc and bcc) by Shishin et al [54] and the liquid metal phase by Jung et al [38] were used in the present study.…”

“…The present thermodynamic optimization has been carried out as part of the wider research program aimed at the complete characterization of phase equilibria and thermodynamic properties and the development of a thermodynamic database for the entire Al-Ca-Cu-Fe-Mg-Si-O-S multi-component system. [54,[62][63][64][65][66] The present optimized model parameters form part of the larger database for metallic, sulfide, oxide systems, which can be used together with the FactSage software [40] for the simulation of high temperature metallurgical processes, such as sintering, steel-making, copper smelting and converting, and for the exploration or development of new processes.…”