PURPOSE: To efficiently and safely dry-pulverize alumina without any trouble in operability by adding a prescribed amount of alumina into polyethylene glycohol or polypropyleneglycohol having a prescribed molecular weight.
CONSTITUTION: A pulverization additive consisting of polyethyleneglycohol having 20-600 molecular weight or polypropyleneglycohol having 400-700 molecular weight is prepared. The pulverization additive of 0.05-0.5wt.% (per alumina) is added into alumina and is pulverized in a ball mill or a vibration mill. As a result, an alumina powder excellent in dispersibility to an aq. medium is obtained excellently in pulverization efficiency, safely and without any trouble in operability. In the case of being applied for a castable refractory use, the alumina powder has excellent fluidability and sinterability even if water amount for kneading is decreased.
SHIBATA SEIJI
KAMEDA ISAO
