METHOD OF PRODUCING ULTRAFINE POWDER OF SILVER AND SILVER ULTRAFINE POWDER OBTAINED USING SAID METHOD Russian patent published in 2016 - IPC C01G5/00 C30B29/60 B22F9/24 

FIELD: medicine.

SUBSTANCE: invention relates to methods for obtaining powder material containing microparticles, and can be used in medicine as a bactericidal material, in chemistry for purification of drinking water; in production of catalysts; in chemical industry for protective coating of pipeline walls; in the chemical current sources. Method of producing ultrafine silver powder includes treatment of water solution of silver nitrate with reducing agent. As a reducing agent the aqueous solution of thiocarbonic acid (thiourea) and ammonium hydroxide is used taken in the following ratio: silver nitrate:thiocarbonic acid diamide (thiourea):ammonium hydroxide = 1:5÷10:0.01÷0.8. Obtained ultradisperse silver powder contains modified particles of star-like shape, having from 32 to 56 pyramidal and wedge-like beams with length of 40-50 microns with average size of the core 5-6 microns, the density of powder is equal to 0.4-0.8 g/cm³.

EFFECT: technical result consists in obtaining of pure metal particles of silver, characterised with modified structure of surface morphology, simple efficient method using safe and ecologically pure substances.

2 cl, 2 dwg, 2 ex