Changes in the pore structure of ironstone china body with heating

The changes in the pore structures of compacts of ironstone china during a heating process were investigated using mercury intrusion porosimeter. A ro llerhead-machine was used to form the compacts of ironstone china, The comp acts were heated at 400-1280 degrees C for 2h. Pore volume and pore size di stribution of the samples were measured by means of mercury intrusion poros imeter. The results obtained were as follows : (1) The pores existed in the ironstone china body are within the range of pore diameter which can be me asured by means of mercury intrusion porosimeter, then, the changes in the pore structures of compacts during a heating process can be discussed by th e results of mercury intrusion porosimetery, (2) Pore volume of green compa cts measured by means of mercury intrusion porosimeter was 157 mm(3)/g, whi ch was agreed with the results of apparent porosity value of 30% measured b y means of Archimedes methods. (3) The pore diameter at maximum mode of dis tributions was 0.2 mu m, and almost of pores were existed in the range betw een 0.02 and 0.35 mu m in diameter, (4) Pore volume of the compact increase d during the heating process at 800-1000 degrees C. Pore volume heated at 8 00-1000 degrees C was 190 mm(3)/g, and then it decreased with heating tempe rature after 1000 degrees C, (5) The pore diameter at maximum mode of distr ibutions became large with the heating temperature and small pore was decre ased, The pore diameter at maximum mode of distributions was about 0.7 mu m in the sample heated at 1220-1240 degrees C, and then it decreased with th e temperature after 1240 degrees C.