Chinese scientists have devised a set of new methods to recover indium from used LCD screens, hoping to develop a closed-loop recycling process before the world’s reserves of the rare metal run out.
The team from the School of Environment of Tsinghua University in Beijing tested 18 methods for removing indium from discarded LCD screens and displays. The methods involved crushing and grinding the LCD glass into particles less than 75 micrometres in size. The researchers then soaked the particles in a sulphuric acid solution at a temperature of 50 ºC.
The set of experiments rendered promising results.
“All the obtained results and findings could contribute to affording a closed-loop recycling process for waste LCDs and sustainable development of indium industries,” the researchers stated in a report published in the journal ACS Sustainable Chemistry & Engineering.
With the electronics industry selling millions of gadgets equipped with LCD screens, displays and panels of various sizes every year, there could easily be supply problems within the next 20 years if a sustainable way of indium recycling is not developed, some estimates suggest.
Indium is used in LCD screens in the form of a thin film of indium tin-oxide which acts as a transparent conductive coating. Recycling of the material is only in its earliest stages at present.
In China - currently the world’s most dynamic electronics market - it is estimated that 100 million TVs, computers and laptops will be thrown away between 2014 and 2020.