Kinetics and Reduction Mechanism from The Carboiodination Reaction of Ilmenite Ore with Different Carbon Reductants

Abstract

The extraction of titanium (Ti) from ilmenite (FeTiO₃) using carboiodination offers a potential method for selective and environmental green processing, especially when employing renewable carbon sources. This study examines the reduction behaviour and kinetics of ilmenite using carboiodination, with graphite and palm-based char serving as the carbonaceous reductants. The experimental procedure was conducted in a vertical tube furnace maintained at 1000 °C under an inert argon atmosphere to ensure controlled reaction conditions. The reaction kinetic analysis was calculated based on first-order kinetic reduction from the gas produced [ carbon monoxide (CO) and carbon dioxide (CO2)] during the reduction process by the gas analyser, while Scanning Electron Microscopy/ Energy-Dispersive X-ray Spectroscopy (SEM/ EDS) analysed the reduction mechanism. Palm char (PC-I) obtained the greatest reaction rate constant (0.002298 moles/s) and yielded 35.7 mass% Ti at 1000 °C, contrary to graphite (G-I), which produced 27.6 mass% Ti. The carboiodination reaction involves the formation of volatile titanium tetraiodide (TiI₄) via the reaction of titanium dioxide (TiO₂) with carbon (C) and iodine (I₂). PC-I’s enhanced performance compared to G-I is attributed to its high surface area, porosity, and catalytic mineral content, which facilitate redox reactions and lower activation energy. The findings indicate palm char’s promise as a sustainable alternative to fossil-based reductants in ilmenite reduction.