Phase transformations of Langkawi ilmenite ore during carbothermal reduction using palm char as renewable reductant

Mohammed, A.I.; Yunos, Nur Farhana Diyana Mohd; Idris, M.A.; Najmi, Nur Hazira; Jamal, Zul Azhar Zahid; Nomura, Takahiro

doi:10.1016/j.cherd.2021.12.048

Cited by 11 publications

(1 citation statement)

References 31 publications

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“…Furthermore, much research has been conducted on the carbothermic reduction of iron oxide using biomass and charcoal experimentally and thermodynamic simulations. It reported that charcoal and biomass from CPO waste could be used as a reducing agent for the reduction process of minerals and ores effectively. , − Reducing gases (CO and H 2 ) are also expected to evolve through thermal decomposition when using biomass or charcoal as a reductant, which enhances the overall reduction. , …”

Section: Introductionmentioning

confidence: 99%

Microstructure Evolution and Phase Transformation of Iron Produced from the Sustainable Carbothermic Reduction Process of High-Pressure Acid Leaching Residue

Setiawan,

Harjanto,

Kawigraha

et al. 2023

ACS Omega

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This paper describes the microstructure evolution and phase transformation of residue from the lateritic nickel ore high-pressure acid leaching (HPAL) during carbothermic reduction using palm kernel shell (PKS) charcoal as a reductant. The study consisted of thermodynamic calculations combined with analysis of reduction experiments. The thermodynamic assessment predicted that the main phases formed during the reduction process were γ-Fe metal, liquid metal, slag, and spinel, with abundance of reducing gas (CO and H2) at the temperature range of 750–1500 °C. The experimental study shows that the resulting product upon cooling was sponge iron or direct reduced iron when HPAL residue-PKS charcoal composites were reacted up to 1400 °C for 45 min. The sponge iron had an average apparent density of 5.8 ± 0.1 g/cm3 and a 90.8 ± 0.4% metallization degree. The microstructure analysis revealed that as the reduction time was increased, small iron nuggets began forming on the surface of the reduced product. By addition of Na2CO3, the separation of iron nuggets from slag appeared to be improved, hence enhancing the overall reduction process. Furthermore, iron nuggets’ highest apparent density and metallization degree were obtained at 7 ± 0.1 g/cm3 and 98 ± 0.5%, respectively, when adding Na2CO3 of 6 wt %. The phase and microstructure analyses also revealed that the iron nuggets comprised coarse pearlite, eutectic cementite, ledeburite, and sulfides. Thus, this study offers alternative sustainable process conditions for simultaneously handling the HPAL residue using PKS waste to produce metallic iron.

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