The nature of micro- and nanocrystalline weathering products of sulfidic ores rich in As and Sb

富含砷（As）和锑（Sb）的硫化物矿石通常被开采，并作为许多重要金属、准金属和原材料的来源。采矿废物，无论是历史上的，最近的，或目前产生的，是一个主要的环境负荷，即使采矿和加工技术正在稳步改善。当与大气和水圈接触时，硫化矿石和相关的采矿废物风化、转化并可能污染环境。在这里，我建议研究晶体结构和晶体化学的矿石风化产物中富含砷和锑。他们是常见的，往往控制流动性和生物利用度的有毒的类金属和金属。然而，其性质尚不清楚。在该提议中，我们将针对来自系统Fe（III）-As（V）-S（VI）-H2O和（Cu，Zn，Ag，Bi，Fe）-Sb（V）-As（V）-H2O的相。也就是说，我们将研究铁砷酸盐kankite，zykaite，和一套以前未知的阶段从Rotgülden（奥地利）。从后一个系统，我们将检查风化产物的四面体砷黝铜矿矿石。除了详细的光学显微镜和电子探针工作，工作的重点是在衍射技术：高分辨率粉末X射线衍射和电子旋进衍射。后一种方法，特别是，将用于破译的耐候产品的纳米级混合物的晶体结构。该项目将成为纳米级自然风化产品的基准研究。虽然透射电子显微镜已普遍用于环境研究，解决复杂纳米混合物中所有相的晶体结构的可能性确实是一场革命。它将打开一扇大门，一个详尽和完整的表征风化产物及其转化序列。

Sulfidic ores rich in arsenic (As) and antimony (Sb) are commonly exploited and serve as a source of many important metals, metalloids, and raw materials. Mining waste, either historical, recent, or currently produced, represents a major environmental load, even though the mining and processing technologies are steadily improving. Upon contact with atmosphere and hydrosphere, the sulfidic ores and the associated mining wastes weather, transform, and may pollute the environment. Here I propose to study crystal structures and crystal chemistry of selected weathering products of ores rich in As and Sb. They are common and often control the mobility and bioavailability of the toxic metalloids and metals. Yet, their nature is not known. Within this proposal, we will target phases from the systems Fe(III)-As(V)-S(VI)-H2O and (Cu,Zn,Ag,Bi,Fe)-Sb(V)-As(V)-H2O. Namely, we will study the ferric arsenates kankite, zykaite, and a suite of previously unknown phases from Rotgülden (Austria). From the latter system, we will inspect weathering products of tetrahedrite-tennantite ores. In addition to detailed optical microscopy and electron microprobe work, the focus of the work is in the diffraction techniques: high-resolution powder X-ray diffraction and electron precession diffraction. The latter method, in particular, will be used to decipher the crystal structure of the nanosized mixtures of weathering products. This project will be a benchmark study of nanosized natural weathering products. Although transmission electron microscopy has been used commonly in environmental studies, the possibility to solve crystal structures of all phases in a complex nanomixture is truly a revolution. It will open the door to an exhaustive and complete characterization of the weathering products and their transformation sequences.