Study On The Formation Mechanism Of MgO-rich Silico-ferrite Of Calcium And Aluminum

The formation process of Mg-rich Silico-Ferrite of Calcium and Aluminum was studied by in-situ XRD.Based on the component analysis and phase analysis of DSCTGA and SEM-EDS,the formation process of SFCAM was studied in detail and systematically.By changing the contents of SiO2,MgO and Al2O3,the migrate of SiO2,MgO and Al2O3 and the mesophase of SFCAM formation process were studied.And then the formation mechanism of SFCAM was summarized.The results are as follows:1)The results of in situ XRD showed that MgO was dissolved into calcium ferrite system to form SFCA through calcium magnesium silicate(CMS),calcium magnesium ferrite(CMF)and magnesium ferrite Mg Fe2O4;MgO and SiO2 promote the phenomenon of solid solution obviously,the rise of MgO will lead to the reduction of SiO2,cogeneration of CMS,SFCAM and other substances.2)The presence of SiO2 inhibited the formation of SFCA-I,and the higher the content was,the effect more obviously.The addition of MgO can promote the formation of SFCAM and reduce the formation temperature of SFCAM.The amount of SFCAM produced in the low temperature zone increases with the addition of MgO.3)The optimum ratio between SiO2 and MgO is 1:1,and when the ratio is below of SiO2,which can promote the formation of SFCAM.When the content of SiO2 increases more than 1:1,the formation of SFCAM is obviously inhibited.4)The effect of Al2O3 on the formation of SFCAM is not obvious,and it has little promotion effect;the increasement of SFCA-I is more obvious with the increasing of Al2O3;the increasement of MgO content can increase the number of active molecules of Al2O3 and make it easier to participate in the solid phase reaction between interfaces.5)From 1200℃ to 1350℃,the amount of SFCAM increases first and then decreases,the most suitable temperature is about 1250℃.Specific temperature is affected by magnesium,aluminum and silicon content of the three will have a small fluctuation.