Unidad Asociada UVA-CSIC al Centro de Astrobiología, Valladolid, Spain,
Environ Sci Pollut Res Int. 2014;21(11):6783-92. doi: 10.1007/s11356-013-1927-z. Epub 2013 Jul 2.
Acidic waters and sulphate-rich precipitates are typical by-products of mining activity such as in Rio Tinto (Huelva, SW Spain). This river drains pyrite mines situated in the Iberian Pyrite Belt which have been in operation since the Bronze Age and probably constitutes the oldest continuously operating mining activity over the world. In the present work, we have used Raman spectroscopy to study a wide range of natural mineral samples collected at Rio Tinto which origin is related to evaporation and mineral transformation processes in a wet and extreme acidic environment. In addition, we simulated the phenomenon of mineral precipitation in controlled conditions by using a simulator developed at the laboratory evaporating natural water collected at Rio Tinto. Also, a series of experiments using the same waters as small droplets have been carried out using micro-Raman technique. The droplets were placed on substrates with different chemical composition and reactivity. The results reveal that the precipitation sequence occurred in Rio Tinto mainly comprises copiapite and coquimbite group minerals followed by several other low hydrated iron sulphates. The experiments carried out on droplets allow estimating with higher accuracy the precipitation sequence.
酸性水和富含硫酸盐的沉淀物是采矿活动（如西班牙西南部的里奥廷托）的典型副产品。这条河流经伊比利亚黄铁矿带的硫铁矿矿，这些矿自青铜时代以来就一直在开采，可能是世界上最古老的持续开采活动。在本工作中，我们使用拉曼光谱研究了在 Rio Tinto 采集的广泛的天然矿物样本，这些样本的起源与在潮湿和极端酸性环境中的蒸发和矿物转化过程有关。此外，我们使用在实验室中开发的模拟器，在控制条件下模拟了矿物沉淀的现象，该模拟器蒸发了 Rio Tinto 采集的天然水。同样，还使用微拉曼技术对相同的水进行了一系列作为小液滴的实验。将液滴放置在具有不同化学成分和反应性的基底上。结果表明，Rio Tinto 中发生的沉淀序列主要包括铜铀云母和铜铀云母族矿物，其次是几种其他低水合铁硫酸盐。在液滴上进行的实验可以更准确地估计沉淀序列。
