The use of recycled glass as a heavy clay product fluxing body additive is not a new concept. CERAM has recently completed a major WRAP funded brick industry project (WRAP project GLA2-018) investigating the energy saving and emissions reducing benefits of using powdered recycled container glass for just such purposes. In addition we have undertaken smaller investigations, with both Electrical Recycling Company Ltd (Privately Funded Project) and ICER/Glass Technology Services Ltd (WRAP Project GLA15-006), in to the potential benefits of using CRT panel glass as fluxing body additive.

There is currently approximately 105,000 tonnes of CRT glass available annually, though this is likely to decline in future years as conventional CRT televisions and monitors are replaced by flat screen technology. Therefore the CRT glass problem could be seen as a declining market, though the ICER 2003 indicated that by 2012 this is only likely to have declined to 100,000 tonnes due to the conversion of conventional television screens to widescreens. In order to counter the likely reduction in long-term availability with advancing television screen technology it is proposed to also undertake a small sub programme of testing to assess the blending potential for CRT panel glass with mixed colour container glass. This will give confidence to the end users with regards to longevity of supply.

Laboratory testing of heavy clay construction products (bricks, roofing tiles and pipes) has identified significant benefits in physical properties by the addition of 3%, 5% and 7% of mixed source crushed and powdered CRT panel glass.

In summary the results indicate:

• For all the products tested 24 hour cold water absorption values are reduced in relationship to the glass content added. This indicates the porosity of the body has been reduced.
• For all the products 5 hour boiling water absorption values are reduced in relationship to the glass content added. This indicates that the porosity of the body has been reduced.
• On the pipe body the Modulus of Rupture (MOR) for the pipes increases with increasing glass content in the body – indicating it is stronger.