Evaluation of iron ore tailings for the production of building materials

Iron ore tailing is a by-product generated during washing of iron ore & its amounts to be around 18-20 million tones per year in India. Storage of this huge amount of iron ore tailing in massive ponds pose environmental hazards. This study considers two Indian sources of iron ore tailings (marked as A1 and A2) & their structural evaluation utilizing X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). XRD analysis shows that A1 sample contains much more iron hydroxide oxide (hydrohematite) than the A2 sample. FESEM study also reveals that the A1 sample is less porous and denser than the A2 sample. The compacts of a mixture of 60 wt % iron ore tailings (A1 & A2 separately) and 40 wt% ferrogeneous type of kaolinitic clay were heated in the temperature range of 850-1000 degrees C. The heated samples were characterized in terms of bulk density, water absorption and cold crushing strength (CCS). The results revealed that such mixture can be used to produce building materials such as bricks (solid & hollow) & pavement blocks. Energy economy & lower production costs are some major benefits. The structural character of iron ore tailing has as important role on the strength development of heated compacts