Disposal of PC and TV sets is a growing problem, involving for over 40 wt. % waste glasses with high Pb (funnel) or Ba-Sr concentration (panel) which cannot be recycled in the glass manufacture. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles, that was appraised by laboratory simulation of the brickmaking processing and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a behaviour substantially plasticity-reducing during shaping-drying (implying a reduction of mechanical strength) and promoting sintering during firing. No significant release of Pb, Ba and Sr was found during firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt. % appear to be practicable, while 5 wt. % glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt. %, depending on the characteristics of clay bodies. The main constraint is that glass must have a particle size below the limit of pan mills used in brickmaking (1 mm).
Recycling PC-TV waste glass in clay bricks and roof tiles
Michele Dondi;Guia Guarini;Mariarosa Raimondo;Chiara Zanelli
2009
Abstract
Disposal of PC and TV sets is a growing problem, involving for over 40 wt. % waste glasses with high Pb (funnel) or Ba-Sr concentration (panel) which cannot be recycled in the glass manufacture. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles, that was appraised by laboratory simulation of the brickmaking processing and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a behaviour substantially plasticity-reducing during shaping-drying (implying a reduction of mechanical strength) and promoting sintering during firing. No significant release of Pb, Ba and Sr was found during firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt. % appear to be practicable, while 5 wt. % glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt. %, depending on the characteristics of clay bodies. The main constraint is that glass must have a particle size below the limit of pan mills used in brickmaking (1 mm).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
