Performance Evaluation of Magnetic Field Intensity on Iron ore slimes

Iron ore industries facing a problem of huge slime generation, dumping causing not only environmental issues but prime natural resources are wasted also. A detailed characterization
followed by beneficiation of two different slimes of iron ores generated during processing of ROM
and dump fines was studied using hydrocyclone followed by wet high intensity magnetic separator to
recover the valuables and as these are already in fine state can be converted to pellets for DRI or blast
furnace application. Slime sample-I, generated from ROM through scrubbing and sizing for coarse
lump as well as fines and classification assayed 59.25% Fe, 5.14% Al 2 O 3, 4.11% SiO 2 , and 4.83%
LOI. The Slime sample-II generated from dump fines after classification assayed 58.4% Fe, 5.27%
Al 2 O 3, 4.67% SiO 2 , and 5.22% LOI. Although the slimes chemical composition is different, XRD
analysis shows that hematite and goethite are major phase whereas gibbsite, kaolinite and quartz are
minor gangue minerals phases. One interesting aspect of the observation is that Slime –I indicated
higher percentage of goethite compared to low grade slime –II. Multi-stage processing has been done
at different magnetic field intensity for two different slimes. Detailed characterization of product
sample has been carried out to study the performance of field intensity on separation efficiency.