The invention discloses a high-purity ultra-fine torispherical
silicon micro-
powder prepared from natural
powder quartz ore and a preparation method of the
silicon micro-
powder. The preparation method comprises the following steps: by taking the cheap natural
quartz ore as a
raw material, adding inorganic dilueted acid which exerts the
grinding aid effect in an ultra-fine
grinding machine so as to prepare ore
slurry, and regulating the pH of the ore
slurry to 2-3; by taking a zirconia ball as a ball-milling medium,
grinding for 2-4 hours in the ultra-fine grinding
machine; when the power of which the particle
diameter is 2mu m reaches 60%-90% in the high-purity ultra-fine
silicon powder, adding reductant
sodium hydrosulfite and complexing agent
oxalic acid, wherein the dosage of the reductant
sodium hydrosulfite is 1-2% of weight of ore powder, and the dosage of the complexing agent
oxalic acid is 0.5-1-5% of weight of ore powder; and after continuing to
grind for a while, washing, filtering and
drying. An ultrafine
processing technology and a purification and bleaching technology are simultaneously achieved in the same equipment; and the preparation method has the advantages of simple process, short flow, low cost and obvious purification effect, and is easy to carry out large
batch production on scale; and the product can be applied to the fields of
electronics, electricians, optical fibers, lasers,
aerospace and the like.