Glass recycling takes waste glass and transforms it into a usable product. Depending on the end use of the glass it may be sorted at material recycling facility into various colours, mainly;
Flint (clear glass)
Brown / Amber glass
Some facilities do not sort the glass and market the material as mixed broken glass. Municipally recycled glass is then sold to glass processors to be cleaned and crushed. Mixed broken glass is usually sold at a negative price by municipalities, known as a tipping fee. The reason for this is the difficulty in processing the mixed broken glass due to high organic content and its limited end-market uses. The glass that has been processed is now known as cullet and is ready to be used in producing new glass or in secondary low value applications.
The reuse of glass containers is preferable in terms of energy savings. However, using recycled glass in the production of new glass or other products significantly decreases energy use. Some secondary applications include use as a construction aggregate, in fiber-glass, highway construction, etc.