Determination of solid solubility and quantitative analysis of free-lime in steel slag by powder X-ray diffraction

Abstract

X-ray diffraction analysis was performed on steel slag samples, and free-lime, which tend to cause hydration and result in swollen slags, were quantitatively analyzed. Simple CaO and solid solutions in the slag samples that correspond to free-lime could be distinguished from each other from the angles of 200 reflections. The contents of divalent-metal oxides that dissolved in CaO forming solid solution were determined from the lattice parameters calculated from the angles of reflection. The values of the contents were sufficiently large for the slags analyzed in this study to suppress the hydration reaction of the solid solution. Quantities of the free-lime were analyzed by the standard addition method. The reflection intensities of slag samples, to which different amounts of pure CaO were added, were measured, and the contents of the simple CaO and solid solution in the slags of each sample were determined separately.