Nowadays, an alternative to reuse is waste disposal which tends to increase to an unacceptable level in relation to the need of preserving the ecological balance. In that way in the construction field have developed technologies that use long "waste" particles (slag, fly ash, etc) environmentally inert, as substitutes for traditional materials. Using waste from foundries, in making road infrastructure can be a necessity of ecological but also economic opportunity for lowland locations that are in areas without significant deposits of rocks. In this paper we consider the two aspects -ecological and economic, the solution founded for the processing of waste being based on conventional crushing and sorting processes. The crushing process of this kind of particles can be obtained through several methods. Indifferent of the used method for the crushing process, you need to act on the material so that in some of these places appear tensions exceed their breaking limit. Crushing method is chosen depending on the physical and mechanical properties of the material, its initial size, degree of crushing etc. Thus, in this paper we follow the choice of an optimal technological flow for obtaining polyhedral shape on different grain fractions.