英文摘要: | 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. |