Surface energy potential of single particles and size distribution of broken particulate materials
The present work assumes that all the molecules that make a particle of a brittle material share its surface energy. This energy is the area of the particle times its surface tension. The specific surface energy of the particle, energy per unit mass or per mole, is also used as a potential that characterizes the energy state of its molecules. It is assumed that the energy for the breakage of a brittle particle is used for the creation of new surfaces. It is also assumed that this energy is distributed among the molecules according to the classical theory by Maxwell-Boltzman. Given the correspondence between the specific energy of a particle and the number of its molecules that share it, one can find the size of a particle and consequently the size distribution of the material produced after breakage. The parameters necessary to complete the task are the energy input, the initial mass of the material, its molecular weight, the shape factors, the density and the surface tension. The last one is a difficult parameter to assess due to the fact that solid materials have structural defects that can cause variation of their surface tension. The present approach also allows the calculation of an equivalent temperature that can be used as an index of the energy state of the system.
Key wordsSurface energy potential Energy distribution Size distribution Comminution Particulate materials
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