Determination of the formal powder filling of a wet ball mill in open ...
1. Introduction. The material content of a ball mill can be defined either as powder filling or as material holdup. Powder filling is the fraction of the total volume of interstices between balls at rest inside a mill filled with powder (Austin et al., 1984).Material holdup, on the other hand, is the mass content of powder or slurry inside a mill depending on whether milling is done dry or wet.