With same ingredient and under same temperature, the smaller the
fineness of the powder after grinding, the higher the specific
gravity and the better the wear resistance. Density of high alumina
ball is mainly affected by initial powders and sintering process.
If the material is not fully burned, or the powder of the raw
material is not thin enough can all cause problems, resulted in low
density. Low density balls does not have enough abrasion resistant
ability, and crack easily.