The Study Of Effect Of Calcium Fluoride On The Crystallization And Properties Of CAS System Glass-ceramic

The CaO-Al2O3-SiO2glass-ceramics were studied in this paper. By introducing tailings,fluorite, and other chemical raw materials in the CAS system glass, slag glass-ceramics weremade through the effective control of heat treatment parameters. Calcium fluoride is a goodnucleating agent in the plasma state in the high-temperature melt, and highly movement inthe melt during the fluoride ion precipitation while cooling. Therefore, this experiments wereprocessed by controlling the amount of calcium fluoride, and adjusting the tailings contentand other oxides; At the same time, the nucleation and crystallization temperatures wereadjusted in certain temperature range. By means of differential thermal analysis （DSC）,X-raydiffraction（XRD）,confocal microscopy and other tests, the effect of microcrystalline phases,microstructure, mechanical properties, chemical stability is researched by adding differentglass composition and do different heat treatment.The research shows that: With the increase of the content of CaF₂and tailings in the glass composition range, the glass transition temperature and the crystallization temperature are lower. its phase species are augite, wollastonite and diopside, using confocal microscopy to observe the microstructure of the material, the grain size is about1μm. When the tailings content of55%, the CaF₂content of8%, the main phase arewollastonite （CaSiO₃）, and the second phase anorthite （CaAl₂Si₂O₈）, the degree of crystallization can be as high as91%; best flexural strength219.1MPa with tailings content of60%and the CaF₂content of9%, bulk density of2.98g/cm³, chemical stability is good, the glass-ceramics can be used in the construction industry, chemical industry as wear resistance, corrosion-resistant pipe.