Low temperature degradation (LTD) of iron oxides was investigated with the aim of
understanding how natural iron ores degrade under different conditions. Minimisation of
this degradation would increase the acceptance level of natural iron ores as feed
materials without prior beneficiation. In addition to temperature and reduction gas
composition, sample positioning in the reduction furnace and sample’s original weight were
also found to influence LTD. Samples placed in the top reaction zone of the furnace, which
have the first contact with the reducing gas, were found to degrade 1.5 times more than
those in the middle and bottom reaction zones. In addition, they presented a wide range of
size in the disintegrated particles than those in the middle and bottom reaction zones.
Furthermore, the samples with an original weight equal to or greater than 5 g, had a
disintegration extent of less than 10%. Therefore, if the reduction gas comes into contact
with a certain material first, before contacting the iron oxide, it may serve to reduce on
LTD during reduction. Furthermore, in laboratory conditions, the occurrence of low
temperature breakdown of the natural iron oxides can be minimised by using samples with an
original weight equal to or greater than 5 g.