Processing Studies on Banded Hematite Quartzite’s of Sandur Sciht, Karnataka, India

The greater demand for high-quality iron ores has forced the iron and steel industries to utilize low-grade iron ores, such as banded hematite quartzite (BHQ). In the present work, a striped hematite quartzite sample from the Haraginadoni area, in the Sandur schist belt, Ballari District, Karnataka, India, was subjected to characterization studies and conventional mineral processing methods to produce pellet-grade concentrate, assayed as Fe > 63.0%, SiO 2 + Al 2 O 3 < 7%, (Al 2 O 3 /SiO 2 < 0.5). The sample was analyzed as 35.70% Fe, 47.44% SiO 2 , 0.75% Al 2 O 3 , 0.06% Mn, 0.07% TiO 2 , 0.03% P, 0.02% S, and 0.83% LOI. We focused on two routes of beneficiating BHQ samples: (1) conventional gravity followed by reverse floatation and (2) magnetic separation followed by cleaning of magnetic concentrate by reverse floatation. Route 1, achieved pellet-grade concentrate through assaying, and was 63.73% Fe, 6.20% SiO 2 , 0.19% Al 2 O 3 , 0.03% Al 2 O 3 /SiO 2 , and 0.23% LOI, D 80 45 µm, with 70.1% Fe recovery and 62.8% concentration efficiency at 39.6 wt% yield. Using Route 2, the process consisted of WHIMS at −74 µm, D 80 54 µm, 10,000 Gauss, and with a 3 mm ball matrix, followed by flotation of the WHIMS concentrate, which produced a concentrate through assaying and was 63.34% Fe, 6.30% SiO 2 , 0.20% Al 2 O 3 (0.03 Al 2 O 3 /SiO 2 ), and 0.20% LOI with 77.4% Fe recovery, achieving a 68.8% concentration efficiency at 44.0 wt% yield, meeting pellet-grade specifications. Comparing and analyzing both routes for the concentration methods, Route 2, i.e., WHIMS and the reverse flotation of WHIMS concentrate, was amenable compared to Route 1.