Manganese and Phosphorus Equilibria between Liquid Copper and MnO-P_2O_5 Slag
The liquid copper alloys containing 0.2-1.0 mass% Mn and 0.03-0.5 mass% P were equilibrated with MnO saturated and unsaturated MnO-P<sub>2</sub>O<sub>5</sub> slags in a molybdenum crucible under a flowing CO<sub>2</sub>/CO or CO<sub>2</sub>/H<sub>2</sub> atmosphere in the temperature range of 1523 to 1673 K.<br> Manganese-phosphorus and manganese-manganese interaction parameters in liquid copper were found at 1623 K as follows:<br><br><i>e</i><sub>P</sub><sup>Mn</sup>= -0.010 <i>e</i><sub>Mn</sub><sup>P</sup>= -0.021 <i>e</i><sub>Mn</sub><sup>Mn</sup>= 0.027<br><br>These values were examined by considering the relationships among oxygen partial pressure, the activities of manganese and phosphorus in liquid copper. The standard free energy changes for the reduction of solid MnO, MnO(s)=<u>Mn</u>+1/2 O<sub>2</sub>(g), and the dissolution of pure liquid manganese in liquid copper, Mn (l)=<u>Mn</u>, were determined as a function of temperature.<br> The activities of MnO and P<sub>2</sub>O<sub>5</sub> in MnO-P<sub>2</sub>O<sub>5</sub> slags were measured at 1573 K as a function of the composition. The temperature dependence equation of the P<sub>2</sub>O<sub>5</sub> activity was also derived in the MnO saturated condition. On the basis of the present results, examination was done concerning phosphorus and manganese equilibria between hot metal and the MnO-P<sub>2</sub>O<sub>5</sub> slag.
- ISIJ international
ISIJ international 37(11), 1043-1049, 1997-11-15
The Iron and Steel Institute of Japan