Breakage behaviour of different materials—construction of a mastercurve for the breakage probability

Abstract

An approach to quantify the grinding behaviour of different materials is presented. Based on a dimensional analysis and on fracture mechanical considerations, two material parameters, fMat. and Wm,min, are derived theoretically. fMat. characterises the resistance of particulate material against fracture in impact comminution. fMat. comprises the effect of particle size on fracture and the resistance against the external load which is quantified by the specific impact energy. Wm,min characterises the specific energy which a particle can take up without fracture. Values for fMat. and Wm,min which determine the grindability of different materials are given. Both the dimensional analysis and the fracture mechanical considerations lead to the same influence of initial particle size, mass-specific impact energy and newly derived material parameters on the comminution result. Experimentally, the material parameters are determined by single-particle impact tests. Together with the initial particle size and the impact energy, they allow for a quantitative description of the breakage probability of different materials in the form of a mastercurve and can also be applied for the qualitative description of the breakage function. The results for five polymers, limestone and glass spheres of different sizes are shown.