Utilising of the oiled rolling mills scale in iron ore sintering process

Up to 5% of steel is lost with the scale at hot rolling operation. This waste contains 69-72% of iron in the form of oxides. However, its recycling is confronted with presence of up to 20% of oil and 10% of water. E.g. when the oiled scale is introduced as an additive to the iron ore sintering mixture, incomplete combustion of liberated oil at heating during sintering process creates problems for gas cleaning and may even lead to damage of the equipment. A possibility to improve combustion of the scale's oil at the sintering process by preparation of a mixture with peat was shown in the laboratory experiments. Industrial trials demonstrate possibility to increase the oil combustion degree at sintering 2.7 times as much. Consumption of the oiled scale was increased from zero to 12.8 kg (in a form of scale-peat blend) per ton of sinter, which allows for closing the loop of this waste at the integrated steelmaking factory. (C) 2010 Elsevier B.V. All rights reserved.