Abstract: The influence of extrusion conditions such as water to powder ratio, extruder frequency and material temperature on kneading，extruding, and carrier properties were studied. The results show that the kneading process, carrier properties are directly affected by extrusion conditions. Based on actual production requirement, the optimum extrusion conditions are found as follows: water to powder mass ratio 1.37~1.40, extrusion pressure of 10~15 MPa, extruder frequency of 35 Hz and then 20 Hz at the point where the peptization starts with external circulating cooling water.

Key words: alumina carrier, carrier properties, kneading, peptization