Laboratory treatments of EAF slag for its use in construction

Abstract

Laboratory treatments of a plant EAF slag sample 71686 were conducted using stabilizers containing P2O5 and air granulation. The results show that it is necessary to add the stabilizers to increase contents of P2O5 from 0.39% to 0.7% for the slag stabilization. By a fast air cooling, most of the granules from the granulation are spherical, with a low internal porosity and dense structure. Content of Fe2O3 in the granules increased from 7.92% to 18.4% and FeO decreased from 14.3% to 7.8%, due to an oxidation during the slag granulation. Contents of metal elements, As, Cd, Cr, Mo, Pb, Ni and Zn, in the leachates from the treated slag samples were lower than the limit values for leaching from inert wastes pursuant to Directive 1999/31/EC. The slag samples after the treatments may then be regarded as environmentally friendly to use in construction. © (2013) Trans Tech Publications, Switzerland.