Production of Indium Concentrate from Waste LCD Screens
Thomas Boundy, Erik Spiller, and Patrick Taylor
Summary: A commercially viable process for the extraction of indium from liquid crystal
displays (LCDs).
Description: Indium tin oxide (ITO) is a transparent electrode material with advantageous
electronic and optical properties. Worldwide, the demand for indium is growing due to the
increased use of touch screen consumer electronic devises. Since the lifetime for these devises
is on average in the United States only a few years, the indium that is contained in end-of-life
liquid crystal display (LCD) screens should be recovered before disposal. The challenge that
current indium recovery methods face is that since the concentration of indium contained
within the LCD unit is relatively low, the volume of glass that is needed to obtain meaningful
amounts of indium is large. As a result, the shipping costs of the LCD screens cut severely into
the potential revenue, and the amount of acid that is used in the leaching operation exorbitant.
This method employs a number of abrasion specific comminution processes that take
advantage of the surface confined ITO to produce an indium rich concentrate that can be
economically leached to recover the indium. The process economics can be further improved
by the separation of other saleable material fractions from the screen such as liquid crystal
blends.
Main Advantages of this Invention
 Improves economics for indium recovery
 Straight forward to apply
Potential Areas of Application
 Large consumer electronics companies
 Indium Leaching Circuits
ID number: 16041
Intel ectual Property Status: US provisional patent
filed.
Opportunity: We are seeking an exclusive or non-exclusive licensee for implementation of this
technology.
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For more information contact:
William Vaughan, Director of Technology Transfer
Colorado School of Mines, 1500 Illinois Street, Guggenheim Hall Suite 314, Golden, CO 80401
Phone: 303-384-2555; e-mail: wvaughan@mines.edu