Surface crystallization of glass based on blast furnace slags

Abstract

Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, surface nucleation of crystals in glass, obtained from metallurgical slags with the addition of SiO₂, is studied. It is shown that the main phases, crystallized from the surface of the samples are melilite (solid solution of gehlenite 2СаО · Al₂O₃ · SiO₂ in akermanite 2СаО · МgO · 2SiO₂) and diopside (CaO · МgO · 2SiO₂). The kinetics of the crystallization of glass is studied and the rates of the surface crystal growth are determined in the glass of nine compositions. The influence of the degree of dispersion of the particles of the original glass on the deposition order of the crystalline phases and the degree of crystallinity of the glass is studied.