METHOD FOR DIAMONDS PURIFICATION Russian patent published in 2009 - IPC C01B33/04 C30B33/12 C30B29/04 C01B31/06 

FIELD: chemistry.

SUBSTANCE: method includes stagewise diamonds treatment in autoclave at increased temperature and pressure under the action of microwave radiation: in the first stage -with mixture of nitric acid and hydrogen peroxide, in the second stage- with mixture of concentrated nitric, chlorhydric and hydrofluoric acids. The treatment in both stages is carried out in acids gas phase at autoclave filling 45-55%, in the first stage the volume ratio nitric acid/hydrogen peroxide is 4:1 respectively, the treatment is carried out at temperature 215-250°C during 15-60 min. In the second stage the volume ratio nitric acid/chlorhydric acid/hydrofluoric acid is 5:4:1 respectively; the treatment is carried out at the same temperature during 15-150 min. In the third stage the mixture is treated with 5% solution of chlorhydric acid/ during 5-15 min and temperature not more than 160°C.

EFFECT: efficiency enhancing of diamonds purification process along with increase of the used equipment productivity and decrease of reagents consumption.

2 ex