A method of recovering particles from a liquid, a froth flotation apparatus, and a method of recovering particles in a flotation cell are disclosed. In an embodiment, the method comprises a technique of exposing the particles to first-size bubbles having a first predetermined size; the first-size bubbles adhering to the particles; and exposing the particles in a liquid, with the first-size bubbles adhering to the particles, to second-size bubbles having a second predetermined size, the second predetermined size being at least approximately ten times larger than the first predetermined size. The method further comprises the second-size bubbles adhering to the particles and engulfing the first-size bubbles on the particles; and using the second-size bubbles adhering to the particles to recover the particles from the liquid. In one embodiment a first surfactant is used to form the first-size bubbles, and a second surfactant is used to form the second-size bubbles.