2009 Volume 49 Issue 9 Pages 1298-1307
In order to clarify the reaction behavior of phosphorus in the multi phase flux, the solid 2CaO·SiO2 piece was reacted with the CaO–SiO2–FeOx–P2O5 slag for 1 to 180 s at 1573 or 1673 K. The interfaces between the original solid and liquid phases were observed and compositions of both phases were analyzed by SEM/EDS.
The result shows that P2O5 is condensed at the rim layer of 2CaO·SiO2 piece very fast in less than 1 s. The P2O5 condensed phases are identified as the mixture of 2CaO·SiO2–3CaO·P2O5 solid solution and the surrounding liquid slag. After reaction for longer time, the reaction behavior of P2O5 depends on the reaction temperature and initial slag composition. Reaction temperature and mole ratio of CaO/SiO2 in the initial slag influence the stability of P2O5 condensed phases. Higher temperature induces the dissolution of P2O5 condensed phases while larger mole ratio of CaO/SiO2 has the opposite effect.