China – Scientists at Tsinghua University’s School of Environment in Beijing say they are closing in on a new method to recover indium from used liquid crystal display (LCD) screens.
For the past 18 months, the team has been exploring crushing and grinding methods that have yielded LCD glass particles of less than 75 micrometres in size. These were then soaked in a sulphuric acid solution at a temperature of 50°C.
‘We found that the leaching process could largely modify the raw material and enhance its activation for further recovery,’ the group declares in the ACS Sustainable Chemistry & Engineering journal. ‘All the obtained results and findings could contribute to affording a closed-loop recycling process for waste LCDs and sustainable development of indium industries.’
They argue that the recycling of LCD screens is quickly becoming a ‘hot issue’, not least because indium deposits are expected to reach a dangerously low level just 20 years from now. Meanwhile, up to 100 million LCD screens are expected to be thrown away between 2014 and 2020.
China recycled 1.3 million tonnes – or 28% – of its e-scrap via ‘authorised’ channels in 2013, according to a recent report by the United Nations University. E-scrap generation in the whole of Asia totalled 16 million tonnes last year, with China ranking first on 6 million tonnes.