Catastrophic swelling of self-reducing pellets in the recycling of solid residues of steelmaking plants

The phenomenon of abnormal swelling during the reduction of composite pellets (fines of iron ore plus charcoal and electric are furnace dust plus coal), was analysed. The abnormal swelling was associated to the formation of iron whiskers. Radial temperature gradients in the pellets may induce to formation of whiskers therefore cause abnormal swelling during reduction process. The decrease of the diameter of the pellets and the increase of the heating rate has eliminated the abnormal swelling during the reduction process.