Utilization of ironmaking and steelmaking slags

smelting of hammerable iron and its treatment in antiquity and Medieval produced also by-product: slag. Because of small yields of iron the process produced only small amounts of slag that did not attract attention of smelters concerning its possible use. the use of slag pieces was only accidental. a lot of slag pieces and blocks from slag pit shaft furnaces were used as a material for mound building around a church in central denmark. the author of this paper found pieces of smithy slag in walls of houses in medieval town Cencelle in italy [1]. in some cases rich sources of iron smelting slags were used by modern smelters. thick layers of iron-rich smelting slags, by-products of etruscan iron smelting in Populonia, were extensively used as an iron source by 2nd world war italian metallurgy. the introduction of charcoal blast furnaces in the 16th century in west europe is also a starting point in regular utilization of metallurgical slags, mainly blast furnace slags. though the first use of blast furnace slag was in road construction, within a short time it acquired the name “material for many ways of utilization”. in the 20th century many institutions and societies appeared with the main aim to support the use of full production of both ironmaking and steelmaking slags. in present the utilization of the slags is the measure of level attained by steel metallurgy in the country or region. in this paper some remarks on ways of ironmaking and steelmaking slags utilization are presented. Paragraphs related to steelmaking slags are restricted to slags from oxygen converter refining, from electric arc furnace processes and from ladle furnace processes. the slags from other steelmaking processes, from tundish of continuous caster and from pig iron treatment processes are not included in this paper.