TITLE:
Pilot Scale Froth Flotation Studies To Upgrade Nigerian Itakpe Sinter Grade Iron Ore To A Midrex-Grade Super-Concentrate
AUTHORS:
S. A. Ola, G.A. Usman, A.A. Odunaike, S.M. Kollere, P.O. Ajiboye, A. O. Adeleke
KEYWORDS:
sinter, middrex, concentrate, froth flotation, super-concentrate
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.8 No.5,
May
20,
2009
ABSTRACT: The sinter grade concentrate of Itakpe iron ore found in the North Central Kogi state of Nigeria
with cumulative undersize of 6.34% and 2.12% passing 90μm and 63μmsieves, respectively, and
that assayed 63.63% Fe, 5.90% silica and 0.72% alumina was ground in ball mill to produce a
pilot plant froth flotation feed with cumulative undersize of 74.37% and 42.94% for 90μm and
63μm sieves, respectively. The ball mill discharge was then treated in three stages of roughing,
cleaning and re-cleaning in a pilot plant froth flotation process line and the products obtained
gave 66.66%, 66.51%, 65.44% (Fe) and total acid (silica and alumina) contents of 4.22%,
4.39%, 5.15%, respectively, for the three stages. The super-concentrate obtained also gave
81.13%, 55.19% and 30.57% cumulative undersize for 90μm, 63μm and 45μm sieves,
respectively. The results obtained showed that the roughing stage of the flotation process
produced a super-concentrate that fall in the range of 66% to 68% for use in midrex direct
reduction plant at the Delta Steel Plant, Nigeria. The lowest total acid gangue content of 4.22%
was also obtained for the roughing stage, indicating that the two subsequent processes of
cleaning and re-cleaning were not needed. Although, the total acid content of 4.22% for the
roughing stage product slightly exceeds the upper limit of 3.50% for the Midrex process, Itakpe
sinter grade concentrates with up to 5% acid gangue has been successfully used at the Delta
Steel Plant Midrex plant.