Resource Management and Utilization of Lean Grade Iron Ore Resources of Karnataka, India

Abstract

As per the National Steel Policy 2017, more than 300 million tons of steel needs to be produced by 2030, to meet the increased demand due to the tripling of per capita consumption of steel in India. Accordingly, the local steel production from the Ballari steel hub of Sandur schist belt is expected to be raised from present 25 million tons per year to 60 million tons per year by 2030, thus necessitating 150 million tons of high grade hard lumpy/pellets for domestic Ballari steel hub alone excluding long term export commitments. Hence, a strategy for processing lean grade iron ores to augment the demand of high-grade iron ores for metallurgical applications is studied. A composite mixed Banded Hematite Quartzite (BHQ) from different ranges of Sandur schist belt, Ballari district, Karnataka, India was subjected to characterization, mineral processing and palletization studies to produce pellets Fe > 62.5 %, (SiO₂+ Al₂O₃)2, 1.00 % Al₂O₃and 1.06 % LOI, comprising fine grained (<70 ?) mainly hematite [55–60%], very fine grained (<40 ?) quartz [35- 40%] and fine grained (<70 ?) minor amounts of martitized magnetite [1–5%], which are mutually intimately intermixed and intergrown, was subjected to beneficiation. The BHQ is amenable to gravity concentration by tabling reverse flotation, and WHIMS produces pellet grade concentrates. The final conventional process comprising gravity concentration, followed by magnetic separation of gravity tails and refining of magnetic fractions by reverse flotation. The final concentrate has produced assaying 64.5% Fe, 6.32% SiO₂, 0.29% Al₂O₃ and 0.63% LOI, with 73% Fe distribution, has met the pellet grade specification. The pellets produced from beneficiated iron ore concentrate is assayed 64.10 % Fe, 6.85 % SiO₂, 0.42 Al₂O₃%. DRI could be produced from the pellets from which steel is produced paving the way for conservation, sustenance, and sustainable development with the viability of using BHQ of the Sandur schist belt.