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Concept
Décyclage
Résumé
Downcycling, or cascading, is the recycling of waste where the recycled material is of lower quality and functionality than the original material. Often, this is due to the accumulation of tramp elements in secondary metals, which may exclude the latter from high-quality applications. For example, steel scrap from end-of-life vehicles is often contaminated with copper from wires and tin from coating. This contaminated scrap yields a secondary steel that does not meet the specifications for automotive steel and therefore, it is mostly applied in the construction sector.
Downcycling can help to keep materials in use, reduce consumption of raw materials, and avoid the energy usage, greenhouse gas emissions, air pollution, and water pollution of primary production and resource extraction.
The term downcycling was first used by Reiner Pilz in an interview by Thornton Kay in SalvoNEWS in 1994. We talked about the impending EU Demolition Waste Streams directive. "Recycling, he said, "I call it downcycling. They smash bricks, they smash everything. What we need is upcycling where old products are given more value not less." He despairs of the German situation and recalls the supply of a large quantity of reclaimed woodblock from an English supplier for a contract in Nuremberg while just down the road a load of similar blocks was scrapped. It was a pinky looking aggregate with pieces of handmade brick, old tiles and discernible parts of useful old items mixed with crushed concrete. Is this the future for Europe?
The term downcycling was also used by William McDonough and Michael Braungart in their 2002 book Cradle to Cradle: Remaking the Way We Make Things.
As we have noted, most recycling is actually downcycling; it reduces the quality of a material over time. When plastics other than those found in soda and water bottles are recycled, they are mixed with different plastics to produce a hybrid of lower quality, which is then molded into something amorphous and cheap, such as a park bench or a speed bump...
Source officielle
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