The present study aims to investigate the use of mixed hematite and magnetite
ores in iron ore pellet production. Pelletizing tests were carried out on
the hematite and magnetite premixed pellet feed. Drop number and compressive
strength tests for green and dry pellets; porosity, compressive strength and
reducibility tests for fired pellets were carried out to determine the
influence of mixing ratios of both iron oxides on those pellet properties.
Experimental results showed that as the hematite content in the mix pellets
is increased, the green drop number decreased from 6.5 to 5.2, the green
compressive strength decreased from 1.51 to 1.28 kg/pellet and the dry
compressive strength decreased from 2.50 to 1.60 kg/pellet. It was
determined that fired compressive strength of mix pellets decreased from 380
to 230 kg/pellet when the hematite content in the mixed pellet is increased.
The reducibility of mix pellets had almost the same trend and it was faster
up to 40 min reduction time. The results showed that the use of hematite
together with magnetite is possible to produce pellets with sufficiently
good quality in terms of wet, dry and fired mechanical strengths. The
porosity and reducibility values of mix pellets were also found to be
adequate to use as feed for the blast furnace.
The study of pelletizing of mixed hematite and magnetite ores