Reutilization of ultimate glassy wastes as high value structural composite materials
Résumé
This work presents a feasibility study for the revalorization of ultimate glassy wastes. A new process was used to convert these wastes into high value structural composite materials that can be used as brake friction materials. As significant amounts of vitrified domestic waste residues (20 to 60 wt%) were used to manufacture these composite materials, this revalorization process is particularly promising in the context of clean technologies and sustainable development as an alternative to the storage of wastes. Thus the aim of this study was to determine the feasibility of using glassy wastes as friction material in automotive brakes and, moreover, to assess whether this revalorization technique of ultimate wastes is both economical viable and environmentally friendly. Specific mechanical properties (friction, wear rate etc) were measured and appeared to be better than those of conventional commercial brake pads. To assess the environmental impact of these composite materials, risk assessment studies were conducted to evaluate the remobilization of hazardous species such as heavy metals that are concentrated in the wastes. Leaching tests were conducted to simulate the effects of weathering. The alteration solutions were analyzed by ICP-MS to evaluate the dissolution rate of the wastes matrix and the amount of heavy metals released. Thermal shock experiments were conducted with laser ablation and ICP-MS to monitor the secondary products rejected at high temperature. Reutilization of wastes for friction applications appeared to be an economically viable opportunity to converse and valorize ultimate glassy wastes respecting environmental regulations.