Influence of the oxygen partial pressure and the boron content on the behavior of boron in calcium silicate melts

The dissolution behavior of boron in a molten slag was evaluated at 1823 K to establish the boron refining mechanism. From the thermodynamic consideration, two refining mechanisms are confirmed, and a modified equation is suggested. In addition, the structural characteristics of boron in molten slag in different oxygen partial pressure were evaluated to confirm the boride and borate behaviors. The changes in ionic state of boron caused by the oxygen partial pressure were confirmed via Raman spectroscopy. In addition, the network forming characteristics of borate and the network modifying characteristics of boride were observed. From the above results, to improve the boron refinement and the slag fluidity, thereby preventing the silicon loss, refinement of the boron through a slag having much lower equilibrium oxygen partial pressure is suggested.