Comparison of iron ores upgraded with Falcon concentrator and magnetic separators assisted by coal reduction-conversion process

Abstract

This study investigated the effects of iron ore roasting on iron ore beneficiation. Hematite-magnetite conversion was comprehensively investigated and characterized by XRD, SEM, and M–H analyses. The magnetic susceptibilities of the materials were shown by Honda–Owen plots. The optimum magnetite transformation conditions were found as 800°C temperature, 10 wt.% coal and 10 min reaction time. Preliminary tests with the unroasted ores were conducted before the optimization and comparison tests. The Box Behnken test design was used for modeling the falcon concentrator separation tests. High-intensity wet magnetic, low-intensity dry magnetic and falcon gravity separators were applied to the roasted and unroasted ores at the optimum test conditions. After conversion, the iron concentrations in the grade that could be sold (>56% Fe) were obtained by the wet magnetic separator and the falcon gravity separator with the recovery yields of 90.87 and 81.72%, respectively. The positive effects of roasting were observed in terms of concentrate yields for the wet magnetic separation and gravity separation methods. However, desired saleable iron concentrates were not achieved by dry magnetic separation experiments, although the recovery yields were raised above 80% after the conversion process.