resumo
The physical, chemical and mineralogical characterisation of the ash resulting from a pulp mill boiler was performed in order to investigate the valorisation of this waste material through the production of added-value glassy materials. The ash had a particle size distribution in the range 0.06-53 mu m, and a high amount of SiO(2) (similar to 82 wt%), which was present as quartz. To favour the vitrification of the ash and to obtain a melt with an adequate viscosity to cast into a mould, different amounts of Na(2)O were added to act as fluxing agent. A batch with 80 wt% waste load melted at 1350 degrees C resulting in a homogeneous transparent green-coloured glass with good workability. The characterisation of the produced glass by differential thermal analysis and dilatometry showed that this glass presents a stable thermal behaviour. Standard leaching tests revealed that the concentration of heavy metals in the leaching solution was lower than those allowed by the Normative. As a conclusion, by vitrification of batch compositions with adequate waste load and additive content it is possible to produce an ash-based glass that may be used in similar applications as a conventional silicate glass inclusively as a building ecomaterial. (c) 2010 Elsevier B.V. All rights reserved.
palavras-chave
SOLID-WASTE INCINERATOR; FLY-ASH; GLASS-CERAMICS; BOTTOM ASH; PAPER; CRYSTALLIZATION; RESIDUES; BEHAVIOR; SLUDGE; REUSE
categoria
Engineering; Environmental Sciences & Ecology
autores
Ribeiro, ASM; Monteiro, RCC; Davim, EJR; Fernandes, MHV
nossos autores
