The principle behind froth floatation process is:
magnetic properties of ore and gangue
electrical properties of gangue particles
difference is the specific gravity of ore and gangue particles
preferential wetting of ore and gangue particles
In froth floatation process, the desired mineral is turned hydrophobic by the addition of a collector chemical. The hydrophobic grains of mineral-bearing ore rise to the surface, forming a foam (called froth). The froth is removed and the concentrated mineral is further refined.
Froth floatation process depends on the difference in wettability of particles by froth agents and not on other physical properties.