Assessment of chemical sensitivity of Waelz slag

Laboratory investigation of Waelz slag stabilization

“…These results complied with those reported in literature (Busè et al, 2014;Milella, 2004;Barna et al, 2000): although the basic process is preferred, due to the higher process yield and the less consumption of kiln refractory, it produces slag with high attitude to release lead. Moreover, due to the high basicity of such a slag, the final solution pH reaches high values that enhance the lead dissolution (Houben et al, 2013;Pierrard et al, 2002).…”

“…Very high concentrations of chromium and lead, together with high levels of barium and zinc classify the EAF powder dragged by the fumes as a hazardous waste. Under these conditions, not only can EAFD not be recycled for other purposes (except for zinc and lead extraction in the Waelz process) but the Waelz slag is also affected by the same environmental problem, which excludes its re-use, as Barna et al (2000) demonstrated very well.…”

“…Based on the mixture and composition of the material charged in the furnace, the operating conditions and the characteristics of the slag cooling, two different types of slag are obtained: silica-rich and lime-rich slags (Barna et al, 2000). Even though the most of the zinc, lead and cadmium are removed and recovered during EAFD treatment, the Waelz slag is still classified as a dangerous and toxic waste due to excessive concentration of As, Cd, Cr 6+ , Cu, Pb, Ba and V (Barna et al, 2000).…”

Leaching of APC residues from secondary Pb metallurgy using single extraction tests: the mineralogical and the geochemical approach

“…The leached amount was, however, relatively low (<1% of the total content) with the exception of the TCLP leachate from sample B ( Table 3). The leachability of As is strongly dependent on the pH, with higher amounts released under acidic conditions [26]; the obtained leaching data indicate that this phenomenon could be taken into account for the TCLP leachates exhibiting slightly higher As leachability ( Fig. 2 and Table 3).…”

Construction demolition wastes, Waelz slag and MSWI bottom ash: A comparative technical analysis as material for road construction

“…In the Basque Country, around 125,000 ton of EAF dusts are treated annually, recovering approximately 30,000 ton of zinc and generating approximately 70,000 ton of an industrial by-product called Waelz slag. Few technical contributions about the characterization and potential of this material have been found in literature (Barna et al, 2000).…”