ULTRAFINE POWDER MADE FROM MONOCRYSTALLINE DIAMOND PARTICLES AND METHOD OF PREPARING SAID POWDER Russian patent published in 2010 - IPC C01B31/06 B82B3/00 

FIELD: chemistry.

SUBSTANCE: invention relates to technology of making powder consisting of finely divided monocrystalline diamond particles, and specifically to abrasive powder which is specifically adapted for use in high-precision mechanical processing. The method involves mechanical grinding of raw material from monocrystalline diamond particles in order to prepare initial ultrafine diamond particles, which are then imparted hydrophilic properties through oxidation of the surface of the diamond particles. The hydrophilic diamond particles are dispersed in water to form a suspension which is regulated and kept weakly alkaline. The suspension then undergoes presorting, as a result of which the fraction with the maximum size of diamond particles which have dimension D₅₀ equal to or greater than 60 nm is removed from the suspension. After removal of the said fraction, the suspension is diluted with water until concentration of diamonds equal to or less than 0.1 wt %. That way, the treated suspension is exposed to centrifugal force, as a result of which a fraction of large diamond particles condenses in form of a solid clot and is then removed from the suspension.

EFFECT: invention enables efficient preparation of ultrafine powder from diamond particles smaller than 50 nm with a narrow particle distribution range.

4 cl, 2 ex, 1 tbl, 2 dwg