EVALUATION OF POLLUTANT POTENTIAL RELEASE FROM A BOF STEEL SLAG USED IN A CIVIL ENGINEERING SCENARIO
Basic Oxygen Furnace (BOF) steel slags are industrial by-products resulting from the steelmaking process in oxygen converters. The use of BOF slags in place of natural aggregates in road construction has been restrained due to insufficient volume stability and to the lack of environmental regulation. This study aimed at investigating the potential release of pollutants, especially Cr, V and Ba, from a BOF slag re-used in a civil engineering structure using a multi-scale approach. Chemical and mineralogical characterizations of slag were implemented using micro-analysis techniques (X-ray diffraction, micro X-ray fluorescence and XANES spectrometry, electron microprobe analysis). Batch and column leaching tests were carried out on slag samples, as well as a pH-dependent leaching test using a pHstat system. Finally, a long term survey of the quality of seepage waters from a lysimeter and from an experimental platform was carried out. Conductivity, pH, total dissolved solids and Ca contents of the seepage waters and leaching test eluates were high, mainly due to the presence of free-lime in slag (about 6％ as CaO). The concentration of Ba was rather high in leachates, but Cr and V release was low. Microanalyses carried out on slag grains showed that Cr and V were bound to rather stable ferrous mineral phases, but V was also bound to more reactive calcium silicates. Under the tested conditions, the release of Cr and V was poor due to the low solubility of the ferrous minerals, the trapping of metals during the formation of secondary Ca-Si hydrates, and due to the very alkaline pH of solutions resulting mainly from the dissolution of lime.
Steel slag leaching test mineralogy road construction pollutants
M. LEGRET A. B(E)NARD D. DENEELE P. CHAURAND J. DOMAS J. ROSE.
Laboratoire Central des Ponts et Chaussées, BP 4129, 44340 Bouguenais, France INERIS, Domaine du Petit Arbois, BP 33, 13545 Aix-en-Provence Cedex 04, France CEREGE, Europ(o)le de lARBOIS, BP 80, 13545 Aix-en-Provence Cedex 04, France CTPL, ArcelorMittal Fos-sur-Mer, Aile 3 - Bureau 200, 13776 Fos-sur-Mer Cedex, France
国际会议
北京
英文
430-435
2010-05-17（万方平台首次上网日期，不代表论文的发表时间）