In the alumina production process through the dominant commercial Bayer process red mud by-product, which is not consumable and causes serious environmental challenges is produced. Alternative sustainable process for alumina extraction from bauxite is Pedersen process, which was patented in 1920s and was in operation in Norway for many years before closing down due to economic reasons. In this process bauxite is smelted and reduced, which yields pig iron and a calcium aluminate slag. Alumina is further produced from the slag through a hydrometallurgical process. In the present study, different bauxites with different chemical compositions are smelted with lime and reduced by coke. The smelting reduction is studied through chemical, microstructural and phase analysis. It is shown that complete separation of iron from the slag is possible and in addition the process is effective for partial separation of the other impurities such as Ti, Si, V,… from the Al2O3-containing slag.