Materials recovery from waste cathode ray tubes (CRTs)
With the implementation of the Waste Electrical and Electronic Equipment (WEEE) directive and growing concern about the environmental impact of CRT glass, GTS, in a project led by ICER (Industrial Council for Electronic Equipment Recycyling) set out to identify issues affecting disposal and recycling of CRT glass which in 2002 was estimated at some 104,352 tonnes of glass arisings.
The project set out to estimate current and future arisings, look at existing applications of the waste materials, examine five applications for CRT glass in detail, identify new applications and examine current and emerging techniques for seperating leaded and unleaded glass.
CRTs contain two types of glass: barium/stronium and leaded glass. These are welded together with lead frit, the inside of the screen is coated with a mixture of phosphors and a CRT is usually housed in a plastic casing. This makes the glass unsuitable for recycling use in container glass manufacture.
With an apparent lack of applications for CRT the need was urgent to identify and prioritise applications for CRT glass and some 35 possible applications were identified. Five were eventually targeted for in-depth study:
- bricks and tiles (panel glass);
- flux in brick/ceramic ware manufacture;
- foam glass for insulation;
- manufacture of new CRTs;
- fluxing material for metals smelting.
The report also includes information on arisings of both the waste glass and plastic casings, the existing routes for waste CRT glass, collection and separation methods with recommendations for recycling and collection servies and further research.