Reduction behaviour of Odisha Sands Complex, India ilmenite-coke composite pellets

Abstract

Presently, ilmenite concentrates from Odisha Sands Complex at Chhatrapur, India are utilized to produce TiO2 slag by direct smelting in an electric arc furnace. However, the process involves the consumption of excess electrical energy and difficulty in handling the arc furnace due to frothing effects. A more efficient process of pre-reducing the ilmenite before smelting has been proposed in the present communication. In particular, studies have been undertaken on the reduction process of ilmenite-coke composite pellets. The difference in the reduction behaviour of raw ilmenite and ilmenite-coke composite pellets has been established and compared with that of the pre-oxidized raw pellets. The effects of various processing parameters like temperature, residence time, and reductant percentage on the metallization of composite pellets in a static bed have been investigated. Metallization of about 90% has been achieved at 1250 °C for a reduction period of 360 min with a 4°% coke composition. Furthermore, the reduced pellets have been characterized through chemical analysis, optical microscopy, field emission scanning electron microscopy and X-ray diffraction analysis. The reduction behaviour of composite pellets has also been found better than that of pre-oxidized pellets indicating the former to be more efficient.