Beneficiation and flowsheet development of a low grade iron ore: A case study

Abstract

In the present study a detailed characterization followed by beneficiation of low grade iron ore was studied. The Run of Mine (R.O.M) sample assayed 21.91 % Fe, which is very low grade in nature. The impurities are SiO2 26.25%, MgO 20.48%, CaO 5.85%, Al2O3 1.86% and loss on ignition (LOI) 12.71%. A Davis Tube test was performed for the assessment of the separability of magnetic ores by low intensity magnetic separators. The heavy liquid test was carried out to evaluate the possible response of the sample by the gravity concentration technique. The samples were subjected to jigging, dry low intensity magnetic separation (DLIMS) and shaking table tests. Thus a sufficient concentrate could not be obtained in +1 mm by using jigging and DLIMS. The obtained results show that the a high grade iron concentrate (>65% Fe) with lower recoveries was obtained from shaking table tests by using -1 mm fraction. According to the results a flowsheet was developed. From the developed flowsheet, it is possible to obtain pellet grade concentrate with 65.41% Fe, 2.54% SiO2, 2.79% MgO, 0.70% CaO and 0.32% Al2O3. with 21.42% weight recovery. The overall gangue rejection recovery of the circuit is over 95%.