A blast furnace view on slags

In 1982, SSAB, Lulea Works, converted the blast furnace ferrous burden from an acid to an olivine pellet with a high Fe content. This change made it possible to gradually reduce the slag volume to 150kg per metric ton of hot metal with huge positive effects on the blast furnace operation. SSAB, Oxelosund Works, can present a similar development, initially by increasing the Fe content in sinter and later by converting to a 100% olivine pellet operation in 1995. In addition to a description of the historical development of the properties of SSAB blast furnace slags, this paper describes the technical means and issues as well as the environmental constraints governing future developments of slag volume and chemistry, including effects of changes in burden quality and possible tuyere injection of slag formers.