4. Conclusion
CSK intercalation compound with KAc was prepared and calcined below 400 °C and then used as the aluminosilicate material to prepare the geopolymer. As the intercalation was not complete, the kaolinite–KAc intercalation compound coexisted with the nonintercalated kaolinite, which could resist the decomposition of KAc and not dehydroxylate below 400 °C. The optimum dosage of KAc was 30% by mass of CSK for the intercalation compound, which can form the geopolymer with the best compressive strength of 31 MPa at the lowest calcination temperature of 350 °C. CSK-K calcined between 350 °C and 400 °C can be alkali-activated to form the geopolymer with different strengths, which was related to the effect of intercalation reaction and the content of K+. For CSK-K, the temperature of dehydroxylation can be lower with a higher amount of CH3COO− intercalated, which is bonded to the inner surface hydroxyl groups through hydrogen bonding. The decomposition of KAc intercalated can affect the stability of kaolinite's crystal structure and ions of K+ had an influence in the geopolymerization. CSK-K calcined at low temperature, which can be prepared using inexpensive materials via the simple method with low energy consumption, has great potential as a novel material for the manufacture of geopolymers.