Micron-sized ultrafine iron powder preparation method

The invention relates to a micron-sized ultrafine iron powder preparation method and belongs to the technical field of preparation processes of metallic micron-sized ultrafine powder. The preparation method mainly includes: (1) taking scale oxide separated from the surface layer of incineration waste iron as a raw material, adding a certain amount of graphite reducing agent and appropriate zinc stearate as process control agents, and fully grinding and crushing the materials in a planetary ball mill, with the ball-milling process parameters being 3-5:1 in ball material ratio, 300-500r/min in ball-milling speed, 8-24h in ball-grinding time, so as to obtain iron oxide powder with the particle size being 32-1.2 microns; (2) after sieving of the iron oxide powder, heating the iron oxide powder in a tubular heating furnace, and feeding mixed gas of hydrogen and nitrogen in the volume ratio of 1:4 with the gas flow of 200-300ml/min prior to reduction at the temperature of 300-500 DEG C for 10-30 minutes so as to obtain iron powder with the particle size being 1 micron finally.