Studies on the Morphological Properties of Iron Particles Prepared by Reduction of Iron Salts

Abstract

Iron powders were produced by reduction of iron oxide which prepared by calcination of iron oxalate, oxyhydrate, sulphate and formate, and also were produced by direct reduction of these salts at 400°C, 600°C and 800°C. Their morphological properties were determined by optical microscope and electron microscope.
Observation by electron microscope showed that iron particles produced, in all cases, consisted of small unit particle which were linked with each other, resulting in an aggregate. The size of the unit particle increased with increasing temperature and time of reduction. The aggregates of iron powders prepared at the lower reduction temperature, resemble, in shape, the original crystals of the mother salts or the particles of oxides, and thus the shape of aggregates prepared from oxalate was rod like, from oxyhydrate needle like, and from formate rod like. When the reduction temperature was high, however, material transport occured between aggregates and the aggregates lost their original shape. The effects of preparating method on the size and shape of the iron particle were also observed.