Abstract This paper investigates the effect of energy/power input on the flotation of three sulphide minerals (galena, pyrite & pentlandite) and three oxide minerals (apatite, hematite & quartz) in an oscillating grid flotation cell (OGC). Oscillating grids generate near ideal hydrodynamic environments, characterised by turbulence which is relatively homogeneous and isotropic. Galena, pyrite, pentlandite (− 150 μm), apatite (− 650 μm), hematite (− 75 μm) and quartz (− 75 μm) were floated in the OGC at power intensities from 0.1 to 5.0 W/kg, using 0.13, 0.24, 0.58 and 0.82 mm bubbles, and at three collector dosages. Results show that the effect of power intensity on the flotation rate is strongly dependent on the mineral type, particle size, bubble size and collector dosage. In general, fine particles benefit from higher energy inputs, intermediate particles have an optimum energy input, and coarse particles do not benefit from agitation.