Effectiveness factor F_c
0.76
coarse rate depressed to 76% of theoretical
F_c = 1 / (1 + q₂·(|1/x_f − 1/x_c|^α · m_f)²), silica fit: α=0.620, q₂=7.000 mm^1.24
Source: "On the origin of non-linear breakage kinetics in dry milling.pdf" — Topic 8, Part 4