ENVIRONMENTAL PROTECTION THROUGH UTILIZATION OF RECYCLED GLASS AS FLUXING AGENT IN THE STRUCTURAL CERAMICS INDUSTRY Laboratory of Heat Transfer and Environmental Engineering Department of Mechanical Engineering Aristotle University Thessaloniki
Laboratory of Heat Transfer and Environmental Engineering (LHTEE) http://aix.meng.auth.g r/lhtee/index.html
Introduction to the LIFE Clayglass project, EU glass sector overview, Waste avoidance, separate collection of recyclables, sorting of recyclables (paper, glass, metal, plastic, etc.), Principles of waste management (e.g. EU approach), Polluter and producer pays principle, Precautionary principle, Waste hierarchy, Concept from cradle to grave
EU glass sector overview The EU is the world's biggest producer of glass with a market share of around one third of total world production. In 2012, the sector employed 100 thousand people. The glass sector covers container glass (60% of output in tonnage, but about 54% in terms of value); flat glass (about 30% in both tonnage and value); domestic glass, special glass, and reinforcement glass fibres.
Why the ceramic industry is important Employment in 2012, the sector employed 100 thousand people; Link to other sectors the industry is interlinked with other sectors such as construction,automotive, domestic, and leisure. Challenges faced by the glass industry Crisis glass production in the EU was severely impacted by the economic crisis. Germany is the EU s biggest producer (one fifth of the volume produced), followed by France, Spain, Italy, and the United Kingdom. Trade the main challenges include competition, downstream bargaining power, energy prices and a lack of security of supply, substitution by other products, non EU country trade barriers, and the counterfeiting of European designs.
Competitiveness and innovation in the EU glass industry Competitiveness the EU glass industry is represented by large EU based companies. The production process is energy intensive and the manufacturers have to face high start up costs and tied distribution channels. Innovation process research and development has resulted in improvements to energy savings and environmental protection, a switch from fossil to non fossil energy, and glass fibre substituting metals and wood through composites. Export and import about 80% of the glass produced is traded within the EU. Trade barriers non EU countries with strong glass production have been introducing non tariff trade barriers such as compulsory testing and certification schemes.
Sustainability of the EU glass industry Energy efficiency glass production processes are energy intensive and the industry aims to decrease its energy consumption. Waste process waste is usually recycled back to the furnace, but for quality reasons, there is a limit on the amount that can be recycled in sectors such as flat glass and glass fibre. Recycling one of the principal issues for the container glass industry is recycling. Glass packaging is infinitely recyclable and this can positively affect its popularity. Emissions are covered by the Industrial Emissions Directive (IED) and in the best available techniques reference document BREF (4 MB) adopted by the Commission in December 2001. It is now under revision. Legislation the industry falls under the Directives on emissions trading, IED, REACH, packaging and packaging waste, end of life vehicles, and restrictions on hazardous substances.
From a linear economy
to a circular economy
Circular, Zero Waste, Economy Natural Resources & Resource Industries Air Water Land & Minerals Energy Biological Industrial Processes, Distribution & Product Use Waste & Pollution Environmental Industry
Raw materials for the ceramics industry The most important raw material for the ceramics industry, clay, is a sedimentary mineral. There are usually three types of clay used in ceramics: illites, kaolinites (mainly) and at a less extent smectites. Like any mineral, this is also a non renewable natural resource therefore deposits at some point will run out. On the other hand, glass is a material that is being used in several industrial processes and products, which has a very complex problem when it comes to its recovery, recycling or reuse.
(new) Technology and characteristics Basic manufacturing steps are the same. The ceramic mix is differentiated since shredded glass is added The final product characteristics (mainly water absorption and mechanics resistance) are achieved at lower temperatures. The European standards are met by the new product
(new) Technology and characteristics The results obtained from the introduction of glass are satisfactory both aesthetically and technologically. For obtaining good results you need to work with fractions of less than 63 microns. The higher the amount of added glass, the greater is the possible decrease of firing temperature For temperatures below 950 C, the impact of glass is very limited and probably not profitable.
Characteristics of the materials used for testing Sources of recovered glass that were used are: Waste of Electric and Electronic Equipment (WEEE): Cathode Ray Tubes (CRT) and screen glass. Glass originating from end of life vehicles. Glass mixed in the municipal solid waste (MSW) and/or Packaging glass and packaging waste
METHODOLOGY To characterize clays the following analysis has been done: Mineralogical analysis by x ray diffraction (RXD) Chemical analysis by x ray fluorescence (RXF) Dilatometry Heating microscopy. X ray diffraction was used to analyze the mineralogy of clays, and x ray fluorescence was used to analyze the chemical composition clays and glasses in solid samples. The dilatometry and heating microscopy was done in a optic dilatometer MISURA 3.
Diffractograms
Dilatometric curve and heating microscopy
Environmental benefits Depending on the sources used for the estimation of the consumption the natural gas saving in consumption by ton of products manufactured, when the firing temperature is reduced by 150 o C (from 1250 o Cto 1100 o C) is between 10 to 30%. For a medium size plant this means a carbon hydroxide emission reduction between 1800 and 4500 tons of CO 2 /year.
Conclusions The use of reclaimed glass, especially from diverse sources, is a priority for achieving the recycling goals set by the European Commission. Adding reclaimed glass as flux in the structural ceramics industrial process had as result a reduction in energy consumption CO 2 emissions were reduced Production cost was reduced due to the replacement of clay used as raw material with reclaimed glass
AKNOWLEDGEMENTS The presentation was developed in the frame of the project titled Adaptation of the structural ceramics industry to climate change by applying recycled glass as flux (LIFE CLAYGLASS LIFE12/ENV/ES/000156) which is funded by the LIFE financial instrument of the European Community.
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