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偏高岭土基地聚合物高温陶瓷化特性研究
Characteristics of Metakaolinite-Based Geopolmers after Exposure to High Temperatures
【摘要】 以偏高岭土为原料,分别以钠水玻璃和钾水玻璃为碱激发剂,制备地聚合物,并对两组地聚合物样品高温陶瓷化特性进行研究。地聚合物样品的XRD、线性收缩、气孔率和抗压强度分析表明,在800~1000℃时,两组地聚合物均呈无定形凝胶状态; 1100℃开始,由于粘性烧结,K-基地聚合物开始形成稳定的白榴石陶瓷相,线性收缩达到最大值23%,气孔率达到最小值1. 22%,抗压强度提高至47. 76 MPa; Na-基地聚合物在1200℃开始出现霞石陶瓷相和大孔莫来石相,气孔率最小值为3. 10%,最高抗压强度为34. 78 MPa; 1300℃开始,两组地聚合物三维网状结构均完全破坏并生成稳定的陶瓷相。
【Abstract】 The metakaolin, which was mixed with potassium silicate and sodium silicate solution respectively,was used as raw material for the preparation of geopolymer. The characterization of geopolymer under high temperature was investigated. The result show that the geopolymer specimens remain amorphous gel in the 800-1000 ℃ temperature ranges. After calcinating at 1100 ℃ of 6 h,the Kbased geopolymer begins to form the stable leucite ceramic phase due to viscous sintering. In addition,the linear shrinkage and porosity rate of the K-based geopolymer specimens reach a maximum of 23% and a minimum of 1. 22%,respectively. And the compressive strength of K-based geopolymer increases to 47. 76 MPa. Meanwhile,the Na-based geopolymer shows nepheline phase and macroporous mullite phase at 1200 ℃,and its porosity rate reaches a minimum of 3. 10%. The maximum compressive strength of the Na-based geopolymer specimens is up to 34. 78 MPa. After calcinating at 1300 ℃,the threedimensional network structure of the geopolymer is completely destroyed and converts to the stable ceramic phase.
【Key words】 geopolymer; high temperature; linear shrinkage; porosity rate; compressive strength; ceramic phase;
- 【文献出处】 硅酸盐通报 ,Bulletin of the Chinese Ceramic Society , 编辑部邮箱 ,2019年04期
- 【分类号】TQ170.7
- 【被引频次】12
- 【下载频次】289