"Alexandru Ioan Cuza" University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi, Romania.
Gottfried Wilhelm Leibniz University, Welfengarten 1 D-30167, Hannover, Germany.
Sci Total Environ. 2016 Jan 15;542(Pt A):629-41. doi: 10.1016/j.scitotenv.2015.10.139. Epub 2015 Nov 3.
The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30-90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid.
巴亚斯普鲁伊（Baia Sprie）浅成热液系统以其丰富的矿物组合而闻名，为酸性矿山排水提供了有利条件，可以被视为全球受影响矿区的一个典型范例。废弃的迈因希山露天矿的风化样品已通过 X 射线衍射（XRD）、扫描电子显微镜（SEM）、拉曼和近红外（NIR）光谱进行了分析。鉴定出的相主要为不同水合度的铁硫酸盐（szomolnokite、rozenite、melanterite、coquimbite、ferricopiapite）、锌和铝硫酸盐（gunningite、alunogen、halotrichite）。为了确定所研究硫酸盐之间的相变，对样品进行了不同温度的加热。成功确定了每种矿物相的分解过程中脱水温度和中间相。在加热实验中，gunningite 是唯一没有发生转变的硫酸盐。所有其他硫酸盐都在 30-90°C 的温度范围内开始脱水。酸性矿山排水是硫酸盐形成的主要原因，这是由黄铁矿氧化引发的，而黄铁矿是丰富的铁硫酸盐的主要来源。基于脱水温度，气候学解释表明 melanterite 的形成和长期存在与大陆性和温带气候有关。除上述地区外，coquimbite 和 rozenite 也归因于干旱/半干旱地区。更稳定的硫酸盐，如 alunogen、halotrichite、szomolnokite、ferricopiapite 和 gunningite，可以在所有气候条件下形成和存在，从干燥的大陆性气候到甚至热带湿润气候。
