METHOD FOR PREPARING ULTRA-FINE HETIAN JADE POWDER

摘要

A method for preparing an ultra-fine Hetian jade powder, comprising: (1) grinding a Hetian jade powder for 20 min-30 h by a ball milling process; (2) dividing the powder in step (1) into a coarse powder and a fine powder; (3) respectively grinding the coarse powder and the fine powder by the ball milling process to obtain a fine powder with a particle size of 150-200 nm; and (4) grinding the fine powder with a particle size of 150-200 nm by the ball milling process to obtain an ultra-fine Hetian jade powder, the ultra-fine Hetian jade powder means at least a part of the powder has a particle size of less than or equal to 100 nm in at least one dimension. The rotational speed of the ball mill in steps (1), (3) and (4) is 50-500 r/min, the grinding medium is zirconia ball, the ball milling liquid is an aqueous solution containing ethanol, and the masses of the ball milling medium and the liquid are both 1-5 times that of the Hetian jade raw powder. In steps (1) and (3), the ball number ratio of small balls, middle balls and big balls of 5-20 : 1-10 : 1-15 is used. In step (4), the ball number ratio of small balls to middle balls of 5-20 : 1-10 is used. The preparation method can fully retain a mineral crystal structure and trace mineral elements of Hetian jades.