Difficulties With Recycling Glass
Glass can be hard for collectors and recyclers to handle. It is breakable -- which can potentially cause worker harm. It comes in different colours and generally needs to be sorted if it is going to recyclers. Different recyclers prefer different colours. Most bottle-to-bottle recyclers prefer clear glass because they can add colour to glass but can't easily remove it. Coloured glass recyclers generally make a product in which colour is less important, like fibreglass insulation.
Contamination is a crucial issue in glass recycling. Not only do different colours of glass contaminate the process, but different types of glass can be an issue. Window glass and ceramics have different melting points than glass and can cause serious damage to glass-making equipment, as well as creating imperfections in the final product.
Glass is heavy, so it is costly to get it to market, especially if markets are far away, as they are here.
It is also very hard on crushing equipment (SARCAN replaces their glass crushers every year). It, like sand, is an abrasive and wreaks havoc with blades and hammer mills.