Activities of Phosphorus in Copper‐Iron Liquid Alloys Saturated with Copper‐Iron Solid Solutions

Abstract

In order to determine the activities of phosphorus and iron in liquid {Cu-Fe-P} alloys, the two coexisting phases of liquid {Cu-Fe-P} alloys + <Cu-Fe-P> solid solutions were brought into equilibrium with a mixture of AI 20 3 + AIP0 4 + Fe xAI20 4 at temperatures of 1416K and 1526K.The oxygen partial pressures were measured with the aid of a solid-oxide galvanic cell of the type:The equilibrium reactions underlying the experiments can be expressed by 2[P]cu + (5/2) (0 2) + <AI203> = 2 <AIP0 4> and x[Fe]cu + (1/2) (02) + <AI20 3> = <FexAI20 4>The Henrian activity coefficient referred to 1 wt pet solution in pure liquid copper could be well expressed by the formulaThe iron activities referred to pure solid iron could be formulated as log aFe =-(0.37 ±0.12) + (500 ±200) /(T/K) .

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

“…The equilibrium reaction underlying the experiments can be expressed by Reactions [3] and [5]. [4], one obtains [20] Values for a Fe along liquidus line aЈbЈ of Figure 4 have been reported by the present authors [17] [21] The thermodynamic system underlying the experiments consists of 11 components, i.e., With 11 components, 6 equilibrium reactions, and 6 phases, we have only one degree of thermodynamic freedom, f; f ϭ (11 Ϫ 6) ϩ 2 Ϫ 6 ϭ 1.…”

“…The experiments were conducted at 1553, 1573, and 1593 K. At these temperatures, slag ␤ occurs at three-phase assemblage of C 3 P ϩ two L's. In addition, the system involves the following reactions; [17] [18] [19] where {CaO} slag and {Cu} Cu , respectively, denote CaO in liquid slag and copper in {Cu-Fe-P} liquid alloys, respectively, and ϽCuϾ SS , ϽFeϾ SS , and ϽPϾ SS are Cu, Fe, and P, respectively, in ϽCu-Fe-PϾ solid solution. In addition, the system involves the following reactions; [17] [18] [19] where {CaO} slag and {Cu} Cu , respectively, denote CaO in liquid slag and copper in {Cu-Fe-P} liquid alloys, respectively, and ϽCuϾ SS , ϽFeϾ SS , and ϽPϾ SS are Cu, Fe, and P, respectively, in ϽCu-Fe-PϾ solid solution.…”

“…Hence, so far as the activities of Fe and P in molten {Cu-Fe-P} are known, the measurements of the equilibrium oxygen partial pressures for Reactions [3] and [5] would result in simultaneous determinations of the P 2 O 5 and Fe x O activities. In order to prepare for such experiments, the authors [6] have measured the activities of P and Fe in such {Cu-Fe-P} liquid alloys saturated with ϽCu-Fe-PϾ solid solution. Hence, it is now possible to measure the activities of P 2 O 5 and Fe x O by using such a slag/metal equilibrium technique incorporating zirconia electrolyte cell.…”

Thermochemical Properties of Copper-Iron-Sulfur Alloy as Reference Metallic Phase for Analyzing Resulfurization

“…O gas FeO 13,15) and then the activities of FeO and P 2 O 5 can be derived by inserting the equilibrium oxygen partial pressures between Cu-Fe-P liquid alloy and oxide phases, P O2 , determined with oxygen probes and the equilibrium phosphorus content, [%P] Cu − Fe − P , into Eqs. ( 7) and ( 9), respectively.…”

“…........... (15) The value for [f S ] hot metal can be estimated by using the interaction coefficients between components in hot metal. 2,16) Reactions (10) and ( 12) represent the dissolutions of diatomic gaseous sulfur into hot metal and copper-iron alloy, and K (10) and K (12) are available in the literature 2 shows that the chemical affinity between silver and sulfur is much weaker than that between copper and sulfur, the equilibrium content of sulfur in silver may be too low to be determined with sufficient accuracy if silver is used as a reference metal in this experiment.…”