Method for preparing nanometer silicon powder by induction plasma pyrolysis of silane

Abstract

The present invention discloses a method for preparing nanometer silicon powder by induction plasma pyrolysis of silane, which comprises the following steps: exciting working gas in an induction plasma reactor to form stable high-temperature plasma; mixing gaseous silane with dilution gas; injecting into a high-temperature plasma thermal field; decomposing the gaseous silane under a joint action of a hot airflow and a high-temperature circulating cooling airflow in the high-temperature plasma thermal field; cooling and condensing silicon atoms generated by pyrolysis into nanometer-scale spherical silicon powder; filtering an airflow wrapped with the silicon powder by filters; depositing the nanometer silicon powder on the surfaces of the filters; then blowing off the nanometer silicon powder by a periodic back blowing airflow; and collecting the nanometer silicon powder. The present invention uses silane gas as a raw material, induction plasma as a main heat source and an ordinary heating pipe as an auxiliary heat source, and has the advantages of high thermal decomposition rate, no electrode pollution and long-term continuous production. The prepared nanometer silicon powder has high purity, high sphericity, narrow particle size distribution, good fluidity and high quality.

Dependencies are inferred from the claim text.