Powder Characteristics of Gibbsite Ground by a Double Rotating Cylinders Mill

Gibbsite powder was ground in air by a double rotating cylinders mill under three different conditions in order to investigate the effect of grinding condition on the characteristics of ground products. Case-1 in which two cylinders are rotated in reverse directions gave higher impact energy of balls than the other cases (Case-2: batch operation and Case-3: continuous operation) in which only the inner cylinder is rotated to attain the same amorphization of the material. The powders produced in Cases-2 and 3 had a larger specific surface area than that by Case-1. Heat generation rate during the dissolution in water of the powder produced by Cases-2 and 3 was much faster than that by Case-1. The reactivity of powder produced by Cases-2 and 3 was higher than that by Case-1.