Attrition scrubbing for recovery of indium from waste liquid crystal display glass via selective comminution

More than three quarters of global indium consumption is used for the manufacture of liquid crystal displays (LCDs). These devices contain indium at concentrations that appear to be too low to be economically valorized by standard hydro- or pyrometallurgical methods under current market conditions. Because indium is a metal critical to many electronics and clean energy technologies, developing commercially viable processes for recovery indium from such end of life products is expected to offer societal benefit. While LCD screens contain indium at low levels, the surface confinement of indium in these devices makes abrasion an intriguing option for concentrating indium to industrially relevant levels. To that end, attrition scrubbing is investigated and shown capable of producing a concentrate upgraded in indium concentration by a factor of 10 with greater than 90% recovery of indium. The same process leaves the LCD glass cleaned of semiconductor elements that are viewed as impurities to the glass recycling sector. Relative economics of such a pretreatment process relative to direct chemical processing routes are presented. (C) 2017 Elsevier Ltd. All rights reserved.