晶核剂对高炉渣微晶玻璃晶化行为的影响

Influence of Nucleation Agent on Crystallization of Blast Furnace Slag Glass Ceramics

以高炉渣为主要原料,采用高温熔融法制备了高添加量高炉渣微晶玻璃。在适合添加量的基础上,利用差示扫描量热分析、X射线衍射分析、扫描电子显微镜等研究了晶核剂种类对高炉渣微晶玻璃晶化行为和抗折强度的影响。结果表明:当高炉渣添加量为67.5%(质量分数)时,晶核剂组成为5%(质量分数)CaF_2+1%Fe_2O_3时,玻璃的析晶活化能E降低至337.7 k J/mol,晶体生长指数n至2.47,析出的主晶相为钙铝黄长石;晶核剂组成为5%Ca F2+1%Cr2O3时,析出主晶相为短柱状的钙铝黄长石和颗粒状的透辉石;晶核剂组成为5%CaF_2+1%Cr_2O_3+3%Fe_2O_3时,析出的主晶相虽仍为钙铝黄长石和透辉石,但E降低至260.3 k J/mol,n增至3.52,样品整体析晶,形成100 nm左右的细小晶粒,抗折强度达到147 MPa。

The blast furnace slag glass ceramics were fabricated with blast furnace slag by a melting method. Based on the optimization of the slag content, the effect of nucleation agents on the crystallization and properties of blast furnace slag glass ceramics was investigated by differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, respectively. The results show that gehlenite is the main phase of blast furnace slag glass ceramic when the mass percentage of blast furnace slag is 67.5%, the 5%CaF2＋l%Fe2O3 can reduce the activation energy E of the glass ceramics to 337.7 kJ/mol, and improve the Avrami index n to 2.47. The main phases of the glass ceramics are gehlenite and diopside when the nucleating agent is 5% CaF2＋I% Cr2O3. A blast furnace slag glass ceramic with mean grain size of about 100nm and high bending strength of 147 MPa is obtained when 5% CaF2＋1%Cr2O3＋ 3%Fe2O3 is used as a nucleating agent, the main phases are still gehlenite and diopside, and the Avrami index n increases to 3.52 and the activation energy E significantly decreases to 260.3 kJ/mol.