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Gypsum recycling is the process of turning gypsum waste into recycled gypsum hereby generating a raw material that can replace virgin gypsum raw materials in the Gypsum Industry. == Gypsum waste definition and types == Gypsum waste primarily consists of waste from gypsum boards. A gypsum board is a wall or ceiling panel made of a gypsum core with paper lining around it. Such boards are also referred to as plasterboards, drywall, wallboards and gyprock. Gypsum waste main also in some countries consist of gypsum blocks and plaster, among others. Three main types of gypsum waste based on their origin can be distinguished:〔European Commission. http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id=4191 Retrieved 3 October 2013〕 * Gypsum waste from the manufacturing of gypsum products. :This waste, which arises at the industrial gypsum production sites, consists of rejects and non-spec materials generated during the manufacturing of gypsum products. The recycling of this waste stream is usually part of the waste avoidance activity of the gypsum plants. The waste is referred to as gypsum manufacturing or production waste and the recycled gypsum obtained from the recycling of this is known as “production waste derived recycled gypsum”.〔WRAP, Technical Report. Life Cycle Assessment of Plasterboard. 2008. http://www2.wrap.org.uk/downloads/Life_Cycle_Assessment_of_Plasterboard.2a99ccc6.5313.pdf Retrieved 26 September 2013.〕 : * Gypsum waste from new construction. :Gypsum waste from new construction activities is typically a clean waste, and primarily consists of off-cuts of plasterboard (drywall, wallboard or gyprock) when the boards have been cut to fit the dimensions of the wall or ceiling. The waste may constitute 15% of the gypsum materials used on the site. Such waste is generally referred to as new construction gypsum waste, and can be reduced by ordering boards “made-to-measure”, but in most markets less than 10% of all orders are “made-to-measure”. * Gypsum waste from demolition and reconstruction :This waste arises when already installed plasterboards (drywalls, wallboards or gyprock boards), that usually have been installed many years ago, are taken out in connection with that the building is demolished or renovated. For this reason some refer to this waste as “old gypsum waste”, whereas the trade usually refer to this waste as “demolition waste”. Different from the two other types of gypsum waste described above, this type of gypsum waste from renovation, refurbishment and demolition works is more likely to present a certain degree of contamination, which can be in the form of nails, screws, wood, insulation, wall coverings etc. For this waste to be recyclable it is required that the equipment processing the waste is capable of separating such contamination from the gypsum to arrive at a pure recycled gypsum. New construction and demolition gypsum waste is both arising after the gypsum products have left the manufacturing sites, and together these two waste types are referred to as post consumer gypsum waste. The recycled gypsum obtained from this is known as post-consumer recycled gypsum.〔WRAP, Technical Report. Life Cycle Assessment of Plasterboard. 2008. http://www2.wrap.org.uk/downloads/Life_Cycle_Assessment_of_Plasterboard.2a99ccc6.5313.pdf Retrieved 26 September 2013.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「gypsum recycling」の詳細全文を読む スポンサード リンク
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