Slag treatment at Kardemir integrated iron and steel works

Integrated iron- and steelmaking plants generate large amounts of solid wastes, which are mainly blast furnace and steel furnace slags, dusts, sludges, etc. The main problem faced at Kardemir integrated iron and steel works is with the steelmaking slags, i.e. open-hearth furnace slag and more recently basic oxygen furnaces (BOF) slag. Over the last 50 years of operation, more than 5 million tons of slag has accumulated in the waste stockyard. To make use of this slag, a slag-processing plant came into operation at Kardemir in 1999. In this plant, after crushing and classification of the slag to various sizes, the magnetic particles present in the slag are separated by electromagnets. The magnetic 10-50 mm product of the slag-processing unit is charged to blast furnaces as raw material and the magnetic pieces in the range of 50-500 mm are charged to BOF as scrap. This study was undertaken with the objective of determining the effects of addition of the above-mentioned magnetic products of the slag-processing unit on the operation and performance of the blast furnace and the BOF No magnetic separation is applied to the - 10 mm fraction and this material is added into sinter mix as a source of iron and fluxing materials. A further objective of the study was determination of the effect of addition of the - 10 mm product of the slag-processing unit on the properties of the sinter and use of slag-added sinter on the operation of the blast furnace. The slag-processing unit has been found to be a good solution to the environmental problems created by the accumulated slag. (C) 2003 Elsevier B.V All rights reserved.