Sink-float ferrofluid separator applicable to full scale nonferrous scrap separation

Design and performance of a ferrofluid levitation separator for recovering nonferrous metals from shredded automobiles are reported. The scrap separator uses an electromagnet to generate a region of constant density within a pool of ferrofluid held between the magnetic poles; a saturated kerosene base ferrofluid as able to float all common industrial metals of interest. Conveyors move the scrap into the ferrofluid for separation according to density. Results of scrap mixture separation studies establish the technical feasibility of relatively pure aluminum alloy and zinc alloy fractions from shredded automobile scrap by this ferrofluid levitation process. Economic projections indicate profitable operation for shredders handling more than 300 cars per day.