Glass recycling is the collection and recycling of used glass and is considered as the archetype of the modern recycling economy. The collection, processing and recycling of waste glass has been prevalent since the seventies in Germany.
Collection in used glass recycling containers
Initially, used glass is collected in the so-called used glass recycling containers in the bring-it-yourself system. As a rule of thumb in Germany, it is separated according to colours: white, green and brown. Special colourations such as blue or red glass are allocated to the green glass section. A strict colour separation is important for the subsequent recycling process. Small quantities of coloured glass cause an unwanted coloration in the white glass melting process and can vice versa lead to a lot of white glass with regards to the decolourization of coloured glass. Such products may then no longer be used, which is why particular attention to the correct separation is paid.
The used glass recycling containers are emptied regularly by waste disposal specialists and/or recycling companies and transported to different glass producing plants. It is then processed there accordingly. This can be done by purification or even by melting of the glasses.
The first essential element of the overall process is the sorting on a conveyor belt. A so-called magnetic separator removes ferruginous contaminants and immediately separates them. In addition, all the major impurities are separated. These include materials made of plastic, wood, ceramics and porcelain. Thus, the used glass is carefully prepared for the recycling process.
The glass shards are then run through a cusher. During this process, two important things are achieved. Firstly the used glass is freed from screw tops, stoppers and aluminium foil. Secondly, the glass shards are reduced to 15 mm pieces. This is the required size for the melting process.
The crushed used glass is filtered out on a processing belt and lighter parts of the glass are sucked out. It is subsequently examined in more detail with a KSP separator with photographic technique and a laser separator. Opaque foreign substances are optically identified and removed. Re-sorting by hand is carried out. Finally, the final testing is carried out and poss. also a partial quantity tested in the laboratory
Our next blog article will explain more about the recycling of glass.
Our second part demonstrates the new re-production of old glass and the recycling of glass at Schäfer Glas.