Hardness characteristics of rocks subjected to crushing

Abstract

1. The hardness of rocks in crushing is sufficiently characterized by a complex index (the reduced work of fracture), including the specific works of fracture by impact and by abrasion (milling). 2. The closest correlative between the productivity of the “Kaskad” mill and the reduced work of fracture corresponds to the expression of the reduced work of fracture as the sum A′=A1+ωA2′, where ω=1–10. For ball crushing, the reduced work of fracture is expressed as the geometric mean, $$A = \frac{{\sqrt {A_1 A_2 } }}{{360}}.$$ 3. The authors have found the relations between the productivities of primary selfcrushing mills and ball mills and the reduced work of fracture.