Preliminary Synthesis of Iron (II) Oxalate Dihydrate from Ilmenite Ore in Bangka, Indonesia

Iron (II) oxalate dihydrate (FeC2O4·2H2O) is extensively developed as a functional material, serving various purposes, including a cathode material in lithium-ferro-phosphate (LiFePO4) batteries, pigments, and photocatalysts. Conversely, the conversion of waste or by-products of titanium processing from ilmenite into economically significant goods is regarded as an environmentally sustainable project, thus emerging as another prominent research topic in the past few years. This research aims to investigate the use of waste or by-products from titanium processing, specifically ilmenite, in the sulfate method. This waste contains iron and will be employed as a precursor in the synthesizing of FeC2O4·2H2O. The synthesis involves a combination of leaching and precipitation methods, with leaching durations varying from 2 to 5 h at a temperature of 90 °C. The components of the materials were identified by X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), and electron microscopy energy dispersive spectroscopy (SEM-EDS). The X-ray diffraction (XRD) results indicated that FeC2O4·2H2O formed a monoclinic structure during crystallization. The ICP-OES analysis revealed that extending the leaching time from 2 to 5 h led to a significant rise in the concentration of Fe from 374.48 to 2220.54 ppm while simultaneously causing a decrease in the extraction of Fe from 87.32% to 24.82%. The SEM analysis showed that the FeC2O4·2H2O samples had a rod-shaped structure, with particle sizes ranging from 2.22 to 3.96 μm. Based on the given data, it can be deduced that the titanium sulfate liquid waste has significant potential to be used as a precursor in the producing of FeC2O4·2H2O.