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

Abstract

The phase transformations of carbothermal reduction of Langkawi ilmenite ore by palm char were studied in reduction temperatures ranging from 1200 °C, 1300 °C, and 1400 °C using a horizontal tube furnace with inert argon gas. The palm shells as renewable carbon reductant for carbothermal reduction of ilmenite ore were converted into palm char using pyrolysis techniques to improve and increase the surface area and carbon content. The present study aims to reduce oxides in ilmenite ore from our local mining to produce titanium oxides by carbothermal reduction process and recycled agricultural waste from palm shell as renewable reductant. The phase and chemical compositions of ilmenite ore and reduced samples were analyzed by XRD and XRF. It was found that ilmenite ore mainly contained titanomagnetite, hematite, and titanium dioxide phases. After carbothermal reduction, the titanomagnetite phase from ilmenite ore was transformed into titanium dioxide, iron titania, iron, and titanium carbide at the highest reduction temperature (1400 °C) via XRD analysis. The phase transformation revealed the porous structure with wider pore size distribution and high carbon from palm char was able to reduce the oxides in ilmenite ore. According to XRF analysis, the TiO2 amount was increased with the temperature; from 25.7 wt.% at 1200 °C up to 50.8 wt.% with the extent of reduction of TiO2 was 78.56% at 1400 °C. The carbothermal reduction of ilmenite ore using palm char as a renewable reductant was possible and promising in mineral ore extractions.