Effect of the composition of raw materials and nucleating agents Crystallization behavior of nepheline-pyroxenic glass

摘要

Different combination of raw materials and nucleating agents were incorporated in the batch of nepheline-pyroxene glass to demonstrate their effect on the crystallization process. The effect of TiO_2, Cr_2O_3 and LiF with respect to crystallization of base glass was studied by differential thermal analysis (DTA). These materials improved the crystallization of glass between 50 to 150 ℃ of heat treatment. When LiF+TiO_2 and TiO_2+Cr_2O_3 were put together in the glass batches, the rate of crystallization of glass was increased in the same manner. The presence of TiO_2+LiF+Cr_2O_3 improved the crystallization of the glass by decreasing the heat temperature by about 60 ℃. CaO/MgO and CaO/Na_2O ratios played an important role in the rate of crystal growth. The increase in the CaO/MgO ratio lowers the crystallization temperature by values ranging between 37 and 46 ℃.