Characterization and Leaching Kinetics of Ilmenite in Hydrochloric Acid solution for Titanium Dioxide Production

Abstract

A kinetic study of ilmenite in hydrochloric acid (HCl) leaching in the presence of reducing agent has been investigated. The effect of temperature ranging from 60 °C to 80 °C and HCl concentrations (4-9 M) on titanium and iron dissolution has been reported. The chemical and mineralogical studies of ilmenite samples was also performed using scanning electron microscopy with an energy disperse X-Ray (SEM-EDX), X-ray diffraction (XRD) and X-ray fluorescence techniques (XRF). From XRD analysis, ilmenite was found to be the main mineral phase in the presence of associated minerals such as rutile and hematite. SEM micrograph indicated that ilmenite before leaching has a homogenous and angular shape. After leaching for 3 hours, a few particles have reduced its particle sizes due to structural disruption during chemical attack by HCl, but some still retain their shapes. From chemical analysis of leached product, it is indicated that 85.6% of titanium dioxide with low iron content. The dissolution of ilmenite leaching in HCl is reasonably agreed well with a shrinking core kinetic model. The apparent activation energy for iron and titanium is 71.9 kJ mol-1 and 90.1 kJ mol-1 respectively.