A technology for preparing nano-metallic
oxide powder with a DC (direct-current)
plasma method comprises steps as follows: a high-purity
metal block is put into a
smelting furnace and is melted, and a melt delivery tube connected with the
smelting furnace is heated; a
reaction chamber is subjected to
vacuum pumping until the pressure reaches 2-10 MPa, cooling air is introduced into the
reaction chamber, and cooling water is introduced into a reactor interlayer arranged in the
reaction chamber; an arc
plasma gasification
system power source of a reactor is switched on, gasification current is adjusted to 10-2,000 A, and
voltage is adjusted to 5-400 V;
inert gas is introduced into the
metal melt, the melt delivery tube is adopted for flow guidance, the gasification reaction is performed, and
metal jet is formed; the metal jet is gasified under the action of arc
plasma so as to form atomic clusters, the atomic clusters are subjected to a reaction with
oxygen,
oxide nanoparticles are formed, is condensed under cold-air negative pressure and enters a
powder collecting chamber with
cold air flow, and the nano-metallic
oxide powder is obtained. The technology is simple, does not need a plasma source and has high yield, and the prepared nano-metallic oxide powder is not prone to agglomeration, is high in purity and facilitates large-scale production.