METHOD OF SEPARATING NATURAL DIAMONDS BY DEGREE OF THEIR SURFACE ROUGHNESS Russian patent published in 2000 - IPC

FIELD: methods of separation of grainy materials by degree of grain surface roughness; applicable in concentration or in production of superhard powders. SUBSTANCE: method includes decoration of grainy material with ferromagnetic powder, their combined mixing, removal of excess of ferromagnetic powder and subsequent separation of grainy material. Prior to decoration, material is separated by grain shape. Decoration is accomplished in presence of liquid supplied in amount equalling 0.4-0.5 wt.% of material. Grainy material is dried before removal of excess of ferromagnetic powder. For decoration, used is made liquid in the form of water or ethyl alcohol. EFFECT: higher efficiency of separation due to increased contrast in adhesion of ferromagnetic material to surface of grainy material. 6 cl, 1 tbl