调质高炉渣非等温析晶动力学研究

Study of Non-isothermal Crystallization Kinetics of Modified Blast Furnace Slag

采用Factsage热力学软件模拟了调质高炉渣矿物的析出过程.结合高温综合热分析(DSC)、场发射扫描电镜(SEM)和X射线衍射仪(XRD)研究了调质高炉渣的析晶过程,并根据DSC曲线用Kissinger,Ozawa和Augis-Bennett方程计算出了析晶反应的活化能.借助Augis-Bennett方程计算了晶体生长指数n,确定了晶化机理.结果表明:随着升温速率的增加,调质高炉渣由三维体积析晶逐渐向表面析晶转变,酸度系数为1.3和1.4的调质高炉渣在高温下的主要析出相均为镁黄长石和钙铝黄长石,析晶活化能分别为469 kJ/mol;471 kJ/mol(T_(p1)),393 kJ/mol(T_(p2)).

The precipitation process of minerals in modified blast furnace slag was simulated with Factsage software. The crystallization process of modified blast furnace slag was studied by using differential scanning calorimeters （DSC） ’ field emission scanning electron microscope （ SEM） and X-ray diffraction（XRD） techniques. Based on the DSC curves’ the crystallization activation energy was calculated by using Kissinger equation,Ozawa equation and Augis-Bennett equation. The crystal growth index n was calculated by using Augis-Bennett equations and the crystallization mechanism was also determined. The results show that with the increasing of heating rate ’ the modified blast furnace slag is changed from three-dimensional volume crystallization to surface crystallization. For the modified blast furnace slag of Mk =1.3 and 1.4,the main precipitations are gehlenite and akermanite,and the crystallization activation energies are 469 kJ/mol,471 kJ/ mol （ Tpi）,393 kJ/mol （ Tp2）, respectively.