Optimization of microwave heating parameter for TiO₂ extraction process from iron sand Indonesia

Microwave heating is environment-friendly technology which is able to reduce titanomagnetite into TiO₂ or titanium metal caused by CO₂ gas does not vacate the furnace. Titanomagnetite is one of the phases contained in Iron Ore with small amount of titanium (less than 10% Ti). This study aims to get a value of optimal parameter on microwave heating for TiO₂ extraction with different power levels and reductor composition. The method used consists of a magnetic separation, oxidation, reduction process using Microwave Batch Furnace reactor, and hydrochloric acid leaching. Titanomagnetite that oxidized at 1100°C temperature for 4 hours in muffle furnace have phase changed into hemoilmenite (pseudorutile + hematite) with power level is 650 Watt. As the antenna helix added on to design of Microwave Batch Furnace, gain from the heat irradiation become higher to ∼34.7 dB. The power level used is 650 watt on variety graphite : iron ore composition are 3.05: 0.6, 3.05 : 1, and 3. 05: 1.4, thus the best reduction product is processed further by leaching in 20% chlorid acid with 1:6 (S/L ratio). X-Ray Diffraction and X-Ray Fluorense test is used to determine the effect of oxidation, reduction, and leaching process on Iron Ore. Results show that graphite has effect to TiO₂ separation from titanomagnetite phase. As the addition of graphite increases, yield process that represented by recovery TiO2 becomes higher to 4.6% Ti. Microwave adsorption confirmed by using Vector Network Analyse. The amount of microwaves adsorption that represented from S-parameter has increased with the addition of graphite to level 3.05:1. The optimal parameter is resulted in 3.05:1 composition ratio and used 4000 watt power.