Patent ID: 6682005
Filing Date: 2004-01-27
Classification: B02C,C22B,Y02P

Abstract:
A process for recovering precious metals and/or heavy minerals from raw materials comprising the steps of:(i) providing a comminuting chamber having an interior space defined, in part, by side and lower walls; (ii) introducing said raw material into said chamber and causing said raw material to fracture into a first fraction of particles which contain a substantial proportion of precious metals and/or heavy minerals and which are of a size in the range at which any precious metals and/or heavy minerals therein are substantially liberated from the remainder of said raw material, a second fraction of particles which are of a size in the same range but which contain substantially less precious metals and/or heavy minerals and a third fraction of particles which are of a size larger than said range; (iii) causing air to flow upwardly in said chamber; (iv) adjusting the rate of upward flow of air of step (iii) in order to cause substantially all of the particles in the first fraction to fall onto said lower wall while particles in the second and third fractions are carried upward in the air flow; and (v) recovering particles which collect on said lower wall for separation of precious metals and/or heavy minerals therefrom.