Separating the CRT glass types for recycling

A leading UK specialist waste processor and recycler, has installed X-ray technology to sort glass reclaimed from cathode ray tubes, as used in televisions and computer monitors

A leading UK specialist waste processor and recycler, MDJ Light Brothers of Lewes in Sussex, has scored a world-first by installing machinery using X-ray technology to sort the different types of glass reclaimed from cathode ray tubes (CRT), as used in televisions and computer monitors.

The equipment, a Varicon-X from S+S Inspection, has never before been used to separate CRT funnel glass, containing lead, from the screen glass, which has a fluorescent coating.

The WEEE Directive, which takes effect on 1st July 2007, to divert more electrical and electronic waste from landfill through improved recycling, recovery and reuse, requires the removal of this coating from CRTs during processing.

The Varicon-X machine, to be installed in a new, 25,000 sq ft building, will be able to process CRT glass at a rate of more than 30,000 tonnes per annum, using normal shift patterns.

The Light Brothers facility will initially be sorting around 15,000 tonnes of CRT annually but it is expected that more CRT glass, collected as a result of the WEEE Directive implementation, will be processed once the new system is fully operational.

Although LCD and plasma flat screens are now replacing traditional CRTs in TVs and monitors, Light Brothers forecasts that the need for effective and efficient CRT glass recycling will continue to increase for at least the next decade.

End-of-life televisions and computer monitors received at the Lewes facility are initially dismantled manually to remove the CRT and other recyclable materials in a process enabling Light Brothers to achieve a materials recovery rate of better than 90% by weight.

After the electron gun and other metal components have been removed, the CRTs are fed into an imploder to reduce the glass to consistent grain size before passing through the Varicon-X.

Its software uses advanced algorithms to identify the two types of glass by monitoring the degree of X-ray absorption and instructing the separation system to direct the glass types into the appropriate hoppers.

"We looked at several systems for accurately separating the core types of CRT glass," says managing director Jonathan Light, "but none could match the Varicon-X at this highly specialised and difficult task.

Our visit to the S+S factory in Germany, where the machine tested our own samples, was very impressive.

Being able to supply customers such as screen manufacturers with guaranteed quality, reclaimed glass will make a big difference to the economics of CRT glass recycling.

Our use of this technology will enable Light Brothers to continue leading the development of recycling and reuse solutions that help Britain address its ever-escalating targets for cutting waste".

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