Processing Studies on a Sub Grade Iron Ore Sample From S.J.H. Mine, Sandur, Karnataka.

A sub grade iron ore sample from SJH mine, Sandur, Karnataka state was received for evolving a process producing diverse concentrates for steel manufacture. The ROM consisted of mostly brown coloured fines with dark grey coloured hard – compact chips. It contained mainly hematite with subordinate amounts of quartz. Ferruginous clay, gibbsite and magnetite were found in minor to trace amounts. The sample analysed 52.65% Fe(T), 19.65% SiO2,2.57 %Al2O3 and 2.09% LOI. The recommended process flow sheet comprises of [1] Wet scrubbing of ROM followed by wet screening over 6 mm screens.[2] Grinding of screen under size to -150 mesh.[3] Wet high intensity magnetic separation at ~13000 gauss,25%S [4] Thickening -Filtration of final concentrate and tails. The diverse product process yielded [a] A lumpy concentrate assaying 60.61% Fe(T), 9.25% SiO2, 1.65 % Al2O3, 1.57 % LOI with 21.6 % Fe recovery at 18.7 wt.% yield. [b] A powdery pellet grade magnetic concentrate assaying 64.00.% Fe(T), 4.74 % SiO2, 1.30 % Al2O3, 1.00 % LOI with 60.4 % Fe recovery yield at 49.6 wt.% yield. The alternative process comprised of [1] Crushing and grinding the ROM to -50 mesh.[2] Wet high intensity magnetic separation at ~13000 gauss, 25% solids after grinding gravity tails to -150 mesh. The scavenger mag concentrate and I and II cleaner magnetic tails are recycled back gravity grinding circuit.[4] Thickening - filtration of final concentrate and final tails. The process yielded a powdery pellet grade magnetic concentrate assaying 63.82.% Fe(T), 5.34 % SiO2, 1.32 % Al2O3, 1.46 % LOI with 90 % Fe recovery yield at 73.8 wt.% yield. Feasibility study is recommended as the project seems viable and sustainable