A new experimental technique for determinations of the activities of P2O5 and FexO—the system CaO-P2O5-FexO

Activities of FeO and P₂O₅ in Dephosphorization Slags Coexisting with Solid Solutions between Di-calcium Silicate and Tri-calcium Phosphate

“…Then, the P 2 O 5 activity in < C 2 S-C 3 P > ss coexisted with CS can be calculated from Eqs. (25), (26) and (27), and is shown by a solid line in Fig. 7.…”

“…The standard states for the activity of P 2 O 5 , a P O 2 5 , and the Henrian activity of phosphorus, h P , were taken as hypothetical pure liquid P 2 O 5 and 1 mass% solution of phosphorus in molten copper, respectively. In {Cu-Fe-P} liquid alloy saturated with < Fe-Cu-P > solid alloy, the activity of phosphorus at dilute phosphorus concentration has been formulated by 27) By combining Eqs. (15) and (17), the Gibbs energy change for Reaction (11) Hence, a P O 2 5 can be obtained by using Eqs.…”

Phase Identification of Crystal Precipitated from Molten CaO–SiO₂–FeO_x–P₂O₅ Slag by High Temperature <i>In-situ</i> X-ray Diffraction

“…A lot of fundamental studies have been performed to understand the dephosphorization mechanisms, as well as to evaluate the phosphorus partitioning in various types of slag. [1][2][3][4][5][6][7][8][9][10][11][12][13] Since the use of calcium fluoride as an additive was restricted, dephosphorization by multi-phase slag (solidliquid coexistent state) has been performed. [14][15][16][17][18][19][20][21][22][23] In this case, the dicalcium silicate (2CaO•SiO 2 , C2S) solid phase precipitates in the molten slag and phosphorus oxide is known to selectively dissolve into the C2S compound as tricalcium phosphate (3CaO•P 2 O 5 , C3P) to form a solid solution.…”

Thermodynamics of Phosphorus and Sulphur Removal during Basic Oxygen Steelmaking

“…It has been reported that steelmaking slag, at such high levels of basicity, may contain such phases. Trömel 13, Fix et al 14, Knuppel and Oeters 15, as well as Hasegawa et al 16, and also Kaida et al 17, had investigated the thermodynamics of P 2 O 5 in heterogeneous slags containing CaO, FeO x and P 2 O 5 and observed that the activities of the oxides of iron and phosphorus, at any particular temperature, remained constant throughout a multi‐phase region, in spite of wide variations in overall chemistry. A similar trend was observed by the present authors as well.…”