Geochemical characterization of dust from arsenic-bearing tailings, Giant Mine, Canada

Dust from uncovered mine tailings at Giant mine, an abandoned in northern Canada, has been a concern for nearby residents. We have utilized microanalytical mineralogical analysis combined with quantitative measurements of phase distribution and bulk concentration to fully characterize the dust currently generated tailings. Surface material was sampled three impoundments on site sieved <63 μm as proxy dust, total suspended particulate (TSP) samples were collected continuously over two months represent airborne that is Inductively coupled plasma-optical emission spectrometry (ICP-OES) -mass (ICP-MS) show elevated concentrations As, Sb, Zn, Pb, Cu Ni all samples; comparison results unsieved As more concentrated fraction The X-ray absorption near edge structure (XANES) indicate mixture As1−, As5+ As3+. Scanning electron microscope-based mineral liberation (SEM-MLA) roaster-generated iron-oxides (i.e., maghemite), calcium-iron arsenate yukonite), arsenopyrite comprise majority As-bearing particles surface tailings; these solid phases, poses greatest risk human health it exhibits highest relative bioaccessibility. A rare lead phase, which may be bioaccessible, also detected minor quantities this identified mimetite through μXRD analysis. Very little arsenic trioxide found samples, no TSP because exposed trioxide-bearing roaster stack emissions during 1950s 1960s buried by recent Soils contain historic emissions, indicates mine-impacted environmental media surrounding impoundment could some cases pose greater than themselves.