EFFECTS OF GRINDING AIDS ON THE SURFACE-P ROPERTIES OF FLAKY GRAPHITE

Dry grinding of raw flaky graphite was carried out using a planetary m ill in the presence of additives such as tri-sec-butylaluminate, 1H, 1 H, 5H-octafluoropentanol and 1-pentanol. Each of the additives proved effective in accelerating the size reduction of the graphite, along wi th in making thin platy particles. The agglomeration of powders and th e ball coating were not observed during the grinding, indicating that the additives spread over on all surfaces including the newly born sur face of the particles resulting in a decrease in surface energy, Fluor opentanol having a high acidity showed a relatively higher effectivene ss of grinding aids than 1-pentanol. The function of the aids for thin ning particles has been explained; i. e., the chemisorption of the add itive molecules on the broken bond plane of the graphite probably faci litates the fracture of particles along the cleavage planes.