Background Recycled glass is produced from cullet, the technical name for crushed waste glass that is ready to be remelted. The glass container industry requires cullet to be ‘oven-ready’ (i.e. guaranteed free of substances such as ceramics, chinaware, stones, plastics or organic matter from food and beverages). This is because the presence of such material in the cullet produces heavy foam on the melt surface, which reduces heat transfer from the flame, creates glass fining problems and increases energy consumption. However, existing techniques for producing 'clean' cullet are somewhat wasteful, as a significant proportion of glass is lost in the process. Some 23-25% of the glass recovered through separated waste collection is currently disposed of in landfills, and this portion is expected to rise to 35% in coming years as the glass container industry’s requirements become more stringent. Objectives The MEIGLASS project’s objective was to demonstrate a method that adapts sophisticated treatment processes for natural minerals to the treatment of cullet. A second objective was to be able to supply the glass container industry with a greater amount of high-quality recycled glass, enabling a further reduction of primary material and energy use. This would reduce the depletion of natural resources and damage done to landscapes, as well as increasing the ecological benefits of glass containers. Energy consumption for the treatment process was to be reduced by recovering the post-consumer plastics present in the glass rejects and transforming them into electric and thermal energy. Specific project actions would include: 1. The design and implementation of a pilot plant for wastewater treatment and biomass separation, followed by a small-scale industrial purification plant. 2. The design, implementation and validation of pilot and industrial-scale plants for producing energy from the post-consumer plastics present in the glass rejects. 3. The testing and evaluation of product performance in destination industries (i.e. glass, ceramics and bricks). Expected results include the recovery of 99% of the fed dirty cullet; a reduction of primary material use in the glass container industry from 50% to 30% (when substituted by glassy sand); a reduction in the number of containers rejected due to impurities; and the partial substitution of traditional thermal energy supply in the beneficiary's treatment plants with gas and fuel oil derived from plastics separated from the cullet. Results The MEIGLASS project successfully demonstrated the technical feasibility, cost efficiency, and environmental benefits of the new process for treating fed dirty cullet rejected by the primary cullet treatment plants, and, as a result, is offering a greater amount of high quality recycled glass to the glass container industry. The project also achieved its targets related to the use of its treated cullet in the ceramics and bricks industries. By the end of the LIFE project, the beneficiary was treating a total of 200 000 tonnes/yr of dirty cullet, derived from some 1 million tonnes/yr of differentiated urban waste collected in central and northern Italy. Some 70% of the 200 000 tonnes/yr went to the glass container industry ('glassy sand'), 20% to the ceramic industry ('ceramic sand'), and 5% to the bricks industry. Only 1% of material is required to go to landfill. The increased availability of clean cullet was shown to reduce average primary material use in the glass container industry from 50% to 30% (when substituted by glassy sand), and in some cases to as little as 10%. In addition, the number of glass containers rejected and recycled to furnace because of impurities was reduced by 1.5-2%. The environmental benefits of this innovative secondary treatment process will be notably higher in the near future because, with the glass container industry requiring higher standards of treated cullet, primary treatment plants' rate of rejected cullet is expected to increase from 23-25% at present up to some 35%. If the glass container industries were to replace 20% of primary material with “glassy sand”, it would produce an energy saving of some 5%. In the ceramic industry, the substitution of alkali-feldspar used in the mixtures of ceramics (some 40%) with ceramic sand, leads to an equivalent reduction of the use of such raw material, which is presently imported from Turkey. This also reduces costs. Moreover, the use of ceramic sand enables a reduction in the use of natrium metasilicate, which implies further energy and costs saving. The new process, if implemented on a national basis in Italy, would allow for an increase in consumption of recycled glass of 350 000-400 000 tonnes/yr (if all landfilled rejects were recovered and recycled), implying a reduction of at least 5% in energy consumption in glass container production. The beneficiary is also considering the application of the wastewater treatment system developed by this LIFE project to normal furnace ready cullet, in order to improve its characteristics, which may reduce the need of primary material in glass container production close to zero. Regarding the goal of energy production: despite delays at the pilot stage, the project found a workable solution for converting plastics into gas and fuel oil. The beneficiary intends to start up the industrial-scale power plant using this technology by the end of 2011. The beneficiary believes that the technology it has developed for cleaning the waste cullet could be of interest to companies in the mining sector, as a way of differentiating their activity using existing know-how and equipment. Further information on the project can be found in the project's layman report (see "Read more" section).