Effects of particle sizes and roasting temperature on the Fe-Ni enrichment of limonite ore from the Wolo mine area, Southeast Sulawesi, using corncob char as reductant

• Published in: IOP conference series. Earth and environmental science 2024-12, Vol.1422 (1), p.12007
• Main Authors: Sufriadin, Shinta, D, Purwanto, Amalia, R, Akhiruddin, Ito, A, Onggang, S
• Format: Article
• Language: English
• Subjects: Chemical composition; Enrichment; Fayalite; Ferric oxide; Food processing; Goethite; Iron; Iron silicates; Light microscopy; Limonite; Mineralogy; Nickel; Optical microscopy; Particle size; Reducing agents; Roasting; Silicon dioxide; Wustite; X-ray diffraction; X-ray fluorescence
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/1422/1/012007

The reduction roasting of a limonite ore sample from the Wolo mine area was investigated using corncob char as a reductant. The objectives of this study were to analyze the effects of particle sizes and roasting temperature on the mineralogical transformation and Fe-Ni enrichment during the roasting process. The limonite ore was prepared into three size fractions of mesh sieves (-100+150, -150+200, and -200 mesh). Limonite ore was roasted with 2g of corn cob char reductant at temperatures ranging between 800 °C and 1100 °C with a 1-hour reduction time. Limonite ore and roasted products were analyzed to determine the mineral and chemical composition using optical microscopy, X-ray diffraction (XRD), and X-ray fluorescence (XRF) methods. Results of the mineralogical analysis indicated that the sample contained chlorite, goethite, lizardite, maghemite, and quartz. Limonite ore is mainly composed of Fe 2 O 3 (53.59%), followed by SiO 2 (12.16%), MgO (2.63%), and Ni (1.52%). Results of reduced roasting of limonite ore exhibited that the ore minerals were transformed into spinel, wustite, fayalite, and some tetrataenite (FeNi). The ore with -100+150 mesh particle and heated at 1,000 °C provided the optimum enrichment of 1.74% Ni and 42.87% Fe, respectively.