Comparative study of low-grade banded iron ores for iron recovery

Abstract

Two low-grade banded iron ores are evaluated as a potential source for meeting the iron/steel demand due to the scarcity of high-grade iron ores. The present study investigates the processing and enrichment of banded iron ores and their comparison with pure iron oxide and synthetic mixture. The feasibility of physical beneficiation, microwave processing, and carbothermal reduction is thoroughly investigated. A trace amount of magnetite in BHJ ore leads to an improved response of microwave exposure compared to pure iron oxide and mixture. Physical beneficiation was found futile in recovering iron values. The energy consumed during the microwave processing is calculated as 405.2 kWh/ton, whereas for conventional reduction is 223.7 kWh/ton. Significant iron enrichment was achieved through structural alteration of the ore. The microwave processing offered faster reduction kinetics and ferrite formation in a short duration. BHJ sample was found suitable for extracting iron values compared to BHQ using carbothermal reduction.