SusChEM: Indium in Magmatic-Hydrothermal Systems

21世纪的新技术，从LCD显示器到触摸屏和太阳能电池，都涉及到一些金属的使用，而就在几十年前，这些金属还不是地球上的主流资源。人类的创新导致了铟的新用途，包括生产氧化铟(ITO)，这是一种既导电又光学透明的物质。这些属性允许将其用作智能手机、平板电脑和相关设备的触摸屏中的有源组件。其结果是，从1990年代到2000年代中期，铟的需求增长了三倍，而ITO对这一增长的需求负有很大责任。这项研究不仅将加深我们对铟在地壳中分布的认识，还将有助于勘探新的含铟矿石，从而有助于满足未来我国对铟的需求。铟的主要来源包括块状硫化物矿床、含花岗岩脉的脉状矿床和其他与花岗岩有关的矿床。铟最常从闪锌矿中回收，闪锌矿是一种锌硫化物矿物。作为这项工作的一部分，我们将进行实验，以填补我们关于铟在次火山岩浆系统的晶相、水相和熔融相之间的分配以及在成矿条件下将铟纳入闪锌矿的热力学方面的关键知识空白。研究结果将有助于对岩浆-热液效率进行定量估计，从而将铟从岩浆中移出，并并入含闪锌矿的矿石中。这项拟议的研究将允许勘探家和研究人员检验高温含铟矿石的形成假说。该项目由NSF 2014财年可持续化学、工程和材料(SusChEM)倡议支持。

New technologies for the 21st century, with applications from LCD displays to touch screens and solar cells, involve the use of some metals that were not mainstream Earth resources just a few decades ago. Human innovation has led to new uses for indium, including the production of indium tin oxide (ITO), a substance that is both electrically conductive and optically transparent. These properties permit its use as the active component in the touch screens of smart phones, tablets, and related devices. As a result, the demand for indium increased three-fold from the 1990s to the mid-2000s, and ITO has been responsible for much of this increased demand. The research proposed herein will not only improve our understanding of the distribution of indium in the crust of the Earth, but will aid in the exploration for new indium-bearing ores, and thereby, help provide for the future indium needs of the country.The primary sources for indium include massive sulfide deposits, vein deposits including granite-related veins, and other granite-related deposits. Indium is most commonly recovered from sphalerite, a zinc sulfide mineral. As part of this work, experiments will be performed to close critical gaps in our knowledge concerning the distribution of indium among the crystalline, aqueous, and molten phases of sub-volcanic magmatic systems, as well as the thermodynamics of the incorporation of indium into sphalerite under ore-forming conditions. Results of the research will permit quantitative estimates of the magmatic-hydrothermal efficiency with which indium can be removed from magmas, and be incorporated into sphalerite-bearing ores. The proposed research will permit explorationists and researchers to test hypotheses for the formation of high-temperature indium-bearing ores. This project is supported via the NSF FY14 Sustainable Chemistry, Engineering, and Materials (SusChEM) initiative.