Effects of Li Substitution on the Microstructure and Thermal Expansion Behavior of Pollucite Derived from Geopolymer

摘要: The purpose of this work was to study the role lithium in cesium-based geopolymers and thermal evolution during heat treatment together with expansion behavior resulting geopolymer ceramic. A series lithium-substituted geopolymers, Cs(1−x)LixGP (where x = 0, 0.1, 0.2, 0.3), were prepared. All samples heated at 1300°C for 2 h on heating studied by a variety techniques. Phase composition, microstructure evolution, behaviors ceramics derived from characterized. specimens exhibited similar evolutionary trends. With increases content, overall mass loss increased gradually due higher hydration energy Li+ than Cs+. Thermal shrinkage these can be divided into four stages, i.e., structural resilience, dehydration, dehydroxylation, sintering, according dilatometer results. introduction Li results two-step sintering geopolymers. average coefficient (CTE) decreased 4.80 × 10−6 K−1 (x 0) 3.61 0.3) increase substitution. reason attributed presence spodumene after treatment, which has relatively low compared pollucite. Meanwhile, molten could serve as buffer phase between pollucite crystals also conducive decline CTE system.