Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

Abstract

Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873–1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

Keywords

iron ores / ore reduction / ore roasting / bio-char / magnetic properties

References

[1] Kim WH, Min DJ. A mass and energy estimation for the hydrogen utilization in the iron-making process. Sci. China Technol. Sci., 2011, 54(7): 1655.

[2] Purwanto H, Jeyadevan B, Takahashi R, Yagi J. Recovery of magnetite from leached laterite-residue by magnetic separation. ISIJ Int., 2003, 43(12): 1919.

[3] Purwanto H, Selamat NFM, Pramusanto Akiyama T. Pre-reduced iron produced from low grade ore using biomass. SEAISI Q. J., 2010, 39(2): 18

[4] Purwanto H, Shimada T, Takahashi R, Yagi J. Reduction rate of cement bonded laterite briquette with CO-CO₂ gas. ISIJ Int., 2001, 41, S31.

[5] Rohadiana DN, Jamal ZAZ, Jamaludin SB, Bari MF, Adnan J. Structural & magnetic characterizations of NiLiZn nanoferrites synthesized by co-precipitation method. J. Mater. Sci. Technol., 2011, 27(11): 991.

[6] Svoboda J. Magnetic Methods for the Treatment of Minerals, 1987, Netherlands, Elsevier, 38

[7] Yunus NA, Ani MH, Purwanto H, Salleh HM, Akiyama T, Abd Rashid RZ. Reduction of briquette composite made of low grade from ore and biomass ash. SEAISI Q. J., 2012, 41(4): 12

[8] Yunus NA, Ani MH, Purwanto H, Salleh HM, Abd Rashid RZ, Akiyama T. Magnetization of low grade iron ore using empty fruit bunch ash. Adv. Mater. Res., 2013, 701, 141.

[9] Yunus NA, Ani MH, Salleh HM, Rashid RZ A, Akiyama T, Purwanto H. Reduction of iron ore/empty fruit bunch char briquette composite. ISIJ Int., 2013, 53(10): 1749.

[10] Luo SY, Yi CJ, Zhou YM. Direct reduction of mixed biomass-Fe₂O₃ briquettes using biomass-generated syngas. Renew. Energy, 2011, 36(12): 3332.

[11] Muta’alim Purwanto H, Saleh N, Pramusanto Characterization of pre-reduced iron sand concentrate pellet with coal. Int. J. Sci. Eng. Technol., 2009, 2(3): 7

[12] Abd Rashid RZ, Purwanto H, Salleh HM, Ani MH, Yunus NA, Akiyama T. Carbon doped iron ore using palm kernel shell. Adv. Mater. Res., 2013, 701, 28.

[13] Hata Y, Purwanto H, Hosokai S, Hayashi JI, Kashiwaya Y, Akiyama T. Biotar ironmaking using wooden biomass and nanoporous iron ore. Energy Fuels, 2009, 23, 1128.

[14] Wu Y, Fang M, Lan LD, Zhang P, Rao KV, Bao ZY. Rapid and direct magnetization of goethite ore roasted by biomass fuel. Sep. Purif. Technol., 2012, 94, 34.

[15] Salleh MAM, Kisiki NH, Yusuf HM, Ab Karim Ghani WAW. Gasification of biochar from empty fruit bunch in a fluidized bed reactor. Energies, 2010, 3(7): 1344.