Abstract
The following results were obtained by using a high-speed mixer granulator and investigating the relationship between the granularity and wettability of aluminum hydroxide and calcium carbonate powders that were surface-treated with stearic acid:
(1) The granulation limit had a strong relationship to dispersibility in water and to the contact angle of the sample powder. Granulation was possible by using water with powders consisting partly of hydrophilic powders.
(2) An induction period of granulation was necessary for seed growth in powders which were highly hydrophobic. This period was influenced by the added water content, mixing speed and the wettability of the sample powder.
(3) The fine powder generation ratio of granules was less with powders which were made partly of hydrophobic than non-treated powders.
