Particle Coalescence During Hydrogen Reduction of Fine Fe₂O₃ Powders

Abstract

Reduction of fine haematite powders was carried out in a pusher furnace in flowing hydrogen under varying reduction conditions. It was shown that during the reduction process the fine particles coalesce and form agglomerates, the internal porosity of which decreases with increasing reduction temperature. The very high overall porosity of the powder compact is not, however, actually lowered, the coalesced particles being surrounded by large pores, and the compact can be easily milled. Loose iron powders sintered under the same conditions, in contrast, result in massive blocks of comparatively high overall density. PM/0383