Mineralogical characterization of arsenic in gold mine tailings from three sites in Nova Scotia
| Autor: | M.C. Corriveau, Michael B. Parsons, Heather E. Jamieson, Gwendy E.M. Hall |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Arsenopyrite
Environmental remediation Metallurgy chemistry.chemical_element General Chemistry Electron microprobe Particulates Optical mineralogy Tailings chemistry Geochemistry and Petrology Environmental chemistry Scorodite visual_art visual_art.visual_art_medium General Earth and Planetary Sciences Environmental science Arsenic General Environmental Science |
| Zdroj: | Geochemistry: Exploration, Environment, Analysis. 11:179-192 |
| ISSN: | 2041-4943 1467-7873 |
| Popis: | Chronic exposure to high concentrations of arsenic (As) in windblown and vehicle-raised dust from tailings sites in Nova Scotia poses a potential health risk to recreational users of these areas and to nearby residents. The exposure may involve inhalation of dust, as well as oral ingestion of particles. It is important to understand the mineralogy and morphology of As-bearing dust particles in order to evaluate the risk posed by near-surface particulates in As-bearing tailings fields, as this will influence the stability and toxicity of As in the wastes. Optical mineralogy, scanning electron microscopy, electron microprobe, X-ray diffraction, synchrotron-based micro-X-ray diffraction (μXRD) and micro-X-ray absorption near edge structure (μXANES), and sequential leach extractions were applied to tailings samples from three sites in eastern Nova Scotia. Arsenic occurs naturally in these gold deposits mainly in arsenopyrite (FeAsS). In the near-surface material of the tailings fields, sulphide minerals have almost completely oxidized to secondary minerals such as scorodite (FeAsO 4 •2H 2 O) and Ca-Fe arsenates. Iron oxyhydroxides contain variable amounts of As 2 O 5 from trace to 30 wt.% and CaO up to 8 wt.%. The presence of multiple As-hosting solid phases, including relatively soluble Ca-Fe arsenates and Fe oxyhydroxides with adsorbed As has important implications for human health risk assessment and remediation design. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|