Pore-size distributions and the microstructure of clay-water and alumina-water system were determined by mercury porosimetry and SEM observation to consider the relation between plasticity and packing structure of the dough. Bimodal distributions of pores were observed in size with submicron (s-pore) and severalmicron (1-pore) regions for the extrudable dough of clay-water system. Submicron pore group (s-pore) corresponded to inter-particle pores which exist among the primary particles. And the several-micron pore group (I-pore), which vanishes during drying process at 100°C, would be corresponded to inter-aggregate pores. The 1-pore has strong relation with extruding behavior of the dough: in the dough with higher extrudability, a larger amount of 1-pore was included and the 1-pore was obviously observed even at water contents lower than the plastic limit. On the other hand, monomodal distributions of pores by s-pore were characteristic for the unextrudable doughs of alumina-water system. It was estimated that the 1-pore, which is filled with water under wet condition, acts as the free space among the aggregate during extrusion to promote the deformation of a dough.
ASJC Scopus subject areas
- 化学 (全般)