OPTICAL ABSORPTION SPECTRA OF QUENCHED GLASSY SLAGS CONTAINING IRON OXIDE.

Abstract

To study the ionic structure of slags, liquid Na//2O-SiO//2-Fe//2O//3, Na//2O-P//2O//5-Fe//2O//3, and CaO-SiO//2-Al//2O//3-Fe//2O//3 slags were equilibrated at different oxygen pressures at 1250 degree C, 950 degree C, and 1500 degree C, respectively. After quenching, optical absorption spectra were obtained for the glassy solid slags. From the peak positions, it is deduced that oxygen anions are located around a ferric cation in the tetrahedral symmetry in Na//2O-SiO//2-Fe//2O//3 slags and in the octahedral symmetry in Na//2O-P//2O//5-Fe//2O//3 slags and around a ferrous cation in both tetra- and octahedral symmetries in all the slags studied. The position of the edge of the observed charge transfer bands shifted to lower energy positions with increase in Fe//2O//3 content, oxygen pressure, and basicity. From the edge shift, it seems that the charge transfer band is essentially due to electron transitions between the ferric cation and oxygen anion. The reproducibility of the peak position was within 50 cm **-**1 (0. 006 ev), and the relative error in the molar extinction coefficient was estimated to be plus or minus 15%.