Sulfuric Acid Leaching of Bangka Indonesia Ilmenite Ore and Ilmenite Decomposed by NaOH

Abstract

lmenite (FeO.TiO2) ore from Bangka island-Indonesia is a potential raw material for synthesizing titanium dioxide (TiO2), which can be used further as pigmen and photocatalyst. The fabrication of TiO2 particles from ilmenite can be carried out through the solvent extraction using sulfuric acid route. Therefore, the solubility of the ilmenite ore in sulfuric acid environment is one of the key factors to obtain the desired TiO2 particles. The current research is aimed at comparing the solubility of pristine Bangka ilmenite ore with that of precedingly decomposed by sodium hidroxide (NaOH) in pressurized and atmospheric reflux reactors. The dissolution of both precursors was carried out in those reactors under various temperatures of 75, 100, 125, 150 and 175°C. The results showed that the optimum dilution was achieved at 150°C. The obtained recovery of ilmenite was 88.8 % for the pressurized reactor and 75.5% for the atmospheric reflux reactor. The solubility of titanium (Ti) element increased steadily to reach a recovery of 68% at 150°C and decreased significantly afterwards. It was also found that the increase of iron (Fe) element solubility was proportional to the increase of processing temperatures.

FeTiO3 as Anode Material for Sodium‐Ion Batteries: from Morphology Control to Decomposition

“…As ilmenite was the only phase present during the treatment and careful washing was performed at the end of the procedure, the appearance of new reflections is ascribed to the decomposition of ilmenite due to the presence of NaOH, as already reported. Although it was not possible to associate these reflections to any of the already reported decomposition products discussed in the previous section, the global decomposition mechanism is in good agreement with literature data suggesting that the ilmenite under basic conditions undergoes a phase separation resulting in iron rich and titanium rich compounds …”

“…Commercial extraction of titania from ilmenite dates back the 1920’s and nowadays the world production is about 5.3 million metric tons with continuous growing of the worldwide TiO 2 demand, while the ilmenite natural reserves estimated for 800.000 tons . Several industrial procedures are applied for the production of TiO 2 (mainly sulphate and chloride process at high temperature) and Ti metal (Kroll process) . Due to the huge volume of production, new less energetic and cheap methods have been developed for the titania extraction.…”

“…Due to the huge volume of production, new less energetic and cheap methods have been developed for the titania extraction. In particular, recently the soda ash roasting and treatments in basic conditions (KOH, NaOH) have been reported . The production of pure titania follows two steps: initially the reaction with the alkaline hydroxide degrades the ilmenite into a sodium titanate and iron oxide.…”

“…. Reaction (1) was proposed also by another group who used NaOH in solid state reaction instead of hydrothermal treatment with KOH obtaining the same results. Jardim et al.…”

“…Among the several different possible industrial and laboratory procedures for the ilmenite degradation, recently alkaline processes have been proposed . Ilmenite powders treated in NaOH or KOH 10 M solution in the temperature range 150–220 °C react giving sodium titanate and iron oxide phases; subsequent acid leaching allows to obtain pure TiO 2 powders . On the base of these considerations, it is thus essential to pay special attention to the control of experimental conditions of the hydrothermal treatment as a method to tune the morphology, as ilmenite is prone to react and degrade under basic environment.…”