抄録
An experimental study was carried out to obtain the solid surface increase produced in the ball mill grinding. The samples used were silica glass, quartz, feldspar, limestone, marble and talc. The pebble mill consisted of a cylinder of 12.5cm-diameter by 12.5cm-long and 35 balls of a 2.8cm diameter having the total weight of 1000g. The tests were done at the speed of 87% of critical one and with the feed size of 14∼20 mesh and feed weight of 200g. On the assumption that the shape factor is six, the specific surface was determined by the permeability method.
As the result, the stepped grinding curves as shown in Figs. 1 and 4 were obtained for the relationship between the solid surface produced and grinding time. The grinding curve for closely elastic solids showed three steps as shown in Fig. 1, but it showed two steps for plastic solids (Fig. 4).
