Phase Separation Kinetics In The Preparation Of Glass Ceramics From Molten Blast Furnace Slag

Blast furnace slag is a waste produced from blast furnace ironmaking,with its main components CaO,SiO₂,MgO,Al₂O₃ and so on.The chemical composition of glass ceramics is similar to that of glass ceramics,so it is possible to provide a theoretical possibility for the preparation of glass ceramics by blast furnace slag.This measure can not only make solid use of solid waste,but also solve the problem of low heat added value and low added value of industrial products.Using the blast furnace slag of Tangshan Iron and Steel Company Limited as the main raw material,by adding CaO,SiO₂,Al₂O₃,MgO,K₂O,Na₂O and other chemical reagents,preparation of glass ceramics by melting method.The effects of Cr₂O₃,TiO₂ and Fe₂O₃ on nucleation temperature,phase composition and microstructure were investigated by means of high temperature integrated thermal analyzer,X ray diffractometer and field emission scanning electron microscope.On the same heating rate,different nucleating agents Cr₂O₃,TiO₂ and Fe₂O₃ were measured.The test results show that the content of Cr₂O₃ increasing can improve the crystallization ability of glass ceramics crystallization,but the content of Cr₂O₃ is too high to conducive the glass ceramics,the content of Cr₂O₃ is about 2%more appropriate;in a certain range TiO₂,Fe₂O₃,increase the content can improve the crystallization ability of glass ceramics,the TiO₂ content is 8%,the crystallization capacity reaches the maximum;the maximum of Fe₂O₃ is 6%.The samples of the three groups with the strongest crystallization were measured at different heating rates.The test results showed that 2%Cr₂O₃,8%TiO₂ and 6%Fe₂O₃ respectively,to form glass ceramics with diopside and augite and diopside crystal phases,the crystallization activation energy were E₁=369KJ/mol,E₂=439.31KJ/mol,E₃=227.78KJ/mol;2%Cr₂O₃ when the heating rate of alpha control at 13.11?/min below the phase index reached 3,which belongs to the crystallization of three-dimensional growth mechanism?volume crystallization?,they are the formation of fine grain and uniform distribution of the glass ceramics;8%TiO₂,6%Fe₂O₃ phase index were 2.23,2.12,showed that the crystal growth are two-dimensional crystal growth mechanism?surface crystallization?,not the formation of fine grain and uniform distribution of the glass ceramics.