Gold flotation from Colorado River sand with the air-sparged hydrocyclone

Pilot-scale tests indicate that effective concentration of fine gold from Colorado River sands can be achieved by flotation with the air-sparged hydrocyclone. The fine sands (55% -400 mesh and 0.01 opt*) from gravity concentration were processed with a 5-cm air-sparged hydrocyclone (capacity ~1.0 t/h dry solids). Concentrate grades as high as 5.0 opt were produced in a single stage at a recovery of 75%. The separation efficiency was significantly better than that achieved in conventional batch flotation experiments.