Ochreous iron-oxyhydroxide precipitates occur at the bedrock surface of Golden Falls as a result of the long-term discharge of acid mine drainage (AMD) produced by chemical weathering of the Chinkuashih gold-copper deposits and tailings. X-ray diffraction, SEM, TEM, FTIR, ICP, and TG-DTA data indicated that the ocher precipiates were dominated by schwertmannite with an average chemical formula of Fe16O16(OH)11(SO4)2.5·16H2O. The schwertmannite occurred as nanometric fibrous crystallites that had an radiating arrangement forming spheroidal aggregates with hedgehog-like surface microstructures and a specific surface area of 76 m2/g. The ICP analysis further suggested that the schwertmannite contained 2,794 ppm As, 439 ppm Al, 115 ppm Cu, and 23 ppm Cr on average. The result implies that the environmental impacts of the Golden Falls AMD may have been deferred and/or reduced by the precipitation of schwertmannite and the sorption of As and metals thereon.
|Translated title of the contribution||A mineralogical study of acid mine drainage precipitates from Golden Falls, Chinkuashih|
|Number of pages||12|
|Journal||The Taiwan Mining Industry|
|Publication status||Published - 2013 Sep|
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)