Correlation of Nano Titanium Dioxide Synthesis and the Mineralogical Characterization of Ilmenite Ore as Raw Material

Abstract

A study on mineral characterization and nano titanium dioxide synthesis from ilmenite ore of Bangka Island, Indonesia, has been carried out using a caustic fusion method and hydrochloric acid leaching. Comprehensive mineral characterization was conducted using X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD) to depict each fractionated particle's elemental composition and mineralogy, i.e., +80, ?80+100, ?100+150, ?150+200, -200+325, and -325 mesh. Other analyses performed are VSM to measure the magnetic properties and SEM to determine the distribution of elements at each particle size. Based on the characteristics of the ilmenite ore, magnetic separation was applied for the initial stage and analyzed gravimetrically. Later processing was the synthesis of nano titanium dioxide, conducted sequentially, including roasting and leaching. Roasting was run at 900°C with and without caustic soda, and then hydrochloric acid was applied. In reference to the elemental analysis, titanium (Ti) concentration is higher in smaller particle sizes and vice versa for iron (Fe) concentration, so the synthesis of nano titanium dioxide was carried out using a -100+150 mesh particle size. The optimum condition for nano titanium dioxide synthesis was 2:1 of NaOH and ilmenite weight ratio, 20% HCl concentration, and 4 hours of leaching time. The nano titanium dioxide (TiO2) obtained was then characterized using XRF, XRD, particle size analyzer (PSA), and transmission electron microscopy (TEM). Roasting with caustic soda showed better nano titanium dioxide purity with 96.04% of TiO2 with particle size in the range of 50–80 nanometers.

Keywords

• caustic soda
• hydrochloric acid
• ilmenite
• leaching
• nano-tio2¬
• roasting