Effect of rice husk volatiles in iron ore reduction and its kinetic study

Abstract

ABSTRACT India is an agricultural country, whose main crop is rice. Processing and milling of rice crops generate waste which is not yet potentially utilized, at most, it can be used for combustion purposes only. Hence, this research attempts to utilize rice husk volatiles (RHv) as a reducing agent for iron ore pellets in iron and steel making. Selected rice husk (RH) consists of approximately 72% volatile matter. The reduction process was carried out at different temperatures at 800, 900, 1000, and 1100°C and time intervals of 15, 30, 45, 60, and 75 min in a double chamber vertical furnace, using RHv as a reducing agent. It has been observed that the reduction percentage of iron ore obtained in case of RHv is 79.01% at 1100°C in 75 min. Field Emission Scanning Electron Microscope (FESEM) and X-ray diffraction (XRD) analysis show the reduced pellets’ morphological characteristics and phase transformation, respectively. Kinetic analysis was done using the shrinking core model and it shows that at lower temperatures, that is, 800, 900, and 1000°C, reduction was diffusion control and followed by chemical reaction control at 1100°C. The activation energy obtained for diffusion and chemical control was 159 KJ/mol and 83.93 KJ/mol, respectively.