REDUCTIVE ROASTING AND MAGNETIC SEPARATION OF GREEK BAUXITE RESIDUE FOR ITS UTILIZATION IN IRON ORE INDUSTRY

The treatment of Greek bauxite residue through reduction roasting and magnetic separation is investigated. A sample of Greek bauxite residue, hematite being the predominant iron carrier mineral, is subjected to reduction roasting to produce a calcine with intensive magnetic properties where magnetite or metallic iron are the main iron mineral phases. The calcine is then subjected to wet magnetic separation so that the magnetic product can be utilized as a feed for sponge or cast iron production. The effect of parameters such as temperature, intensity of reducing conditions, intensity of magnetic field or dispersing agent addition rate on the result of both processes is investigated. It was indicated that reductive roasting at 500 degrees C followed by wet magnetic separation of the calcine produced at low current intensity (0.04 A) and simultaneous addition of a dispersant resulted in the production of a magnetic product with iron content as high as 36%. The obtained results regarding iron recovery were very promising providing input for further research on the optimization of the proposed method.