16. Sintering shrinkage of kaolin

16. Sintering shrinkage of kaolin

Sintering shrinkage refers to a series of physical and chemical changes (dehydration, decomposition, mullite formation, melting of fusible impurities into glass phase filling the voids between particles) occurring in the firing process of dried kaolin blanks, and the shrinkage performance of products can also be divided into linear shrinkage and volume shrinkage. Like drying shrinkage, sintering shrinkage is too large, which can easily lead to cracking of green body. In addition, if a large amount of quartz is mixed in the billet during roasting, it will undergo crystalline transformation (tripartite to hexagonal), make its volume expand, and also produce reverse shrinkage.