High intensity magnetic separation for the clean-up of a site polluted by lead metallurgy.
The industrial history in the district of Linares (Spain) has had a severe impact on soil quality. Here we examined soil contaminated by lead and other heavy metals in "La Cruz" site, a brownfield affected by metallurgical residues. Initially, the presence of contaminants mainly associated with the presence of lead slag fragments mixed with the soil was evaluated. The subsequent analysis showed a quasi-uniform distribution of the pollution irrespective of the grain-size fractions. This study was accompanied by a characterization of the lead slag behavior under the presence of a magnetic field. Two main magnetic components were detected: first a ferromagnetic and/or ferrimagnetic contribution, second a paramagnetic and/or antiferromagnetic one. It was also established that the slag was composed mainly of lead spherules and iron oxides embedded in a silicate matrix. Under these conditions, the capacity of magnetic separation to remove pollutants was examined. Therefore, two high intensity magnetic separators (dry and wet devices, respectively) were used. Dry separation proved to be successful at decontaminating soil in the first stages of a soil washing plant. In contrast, wet separation was found effective as a post-process for the finer fractions.
Environmental Biotechnology and Geochemistry Group, University of Oviedo, C/Gonzalo Gut, S/N, 33600 Mieres, Asturias, Spain.
C
C
Sierra
J
J
Martínez
J M
JM
Menéndez-Aguado
E
E
Afif
J R
JR
Gallego
D001151:Arsenic / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D007220:Industrial Waste; D060328:Magnetic Phenomena; D008669:Metallurgy; D008670:Metals / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000302:isolation & purification*
D007220:Industrial Waste; D008670:Metals; D012989:Soil Pollutants; D001151:Arsenic