Effect of barite on mineralogical composition and structure of iron ore sinter

Barite containing iron ore samples were sintered in a down draft sinter pot aiming at producing sinters having 0.5-5.5 mass%BaO. The influence of barite on maximum sintering temperature, extent of sulphur removal and FeO content in sinter was studied. Qualitative and quantitative phase analyses were carried out using electroprobe microanalyser (EPMA) while the different developed phases were identified with X-ray diffraction (XRD) techniques. The structure of sintered samples was microscopically examined. In sinter, the extent of sulphur removed slightly increases with BaO content up to 1.5 mass%, followed by a considerable increase in 2.5 mass% BaO containing sinter. The sintering temperature decreases with the increase in BaO content giving a maximum decrease in 2.5 mass% BaO. The increase in BaO content up to 1.5 mass% slightly decreases the magnetite content followed by a sharp decrease of 2.5 mass%. Barium ferrite was not detected in sinters containing up to 1.5 mass% BaO and most of BaO was directed to the slag. In 2.5 mass% BaO containing sinter, eutectic and needle structures of barium ferrite solid solutions were developed. The eutectic structure decreased while the needle structure increased in number and size of samples containing.2.5 mass% BaO.