Estudo da sinterização em reator vertical de leito fixo: desenvolvimento de processo para produção de agregado sintético a partir de cinza volante e biomassa

Abstract

The synthetic aggregates have been employed in civil construction as a measure for the reduction of mineral extraction. Within this context, the recycling of industrial waste configured today as the basis of the majority of processes to reduce the exploitation of mineral resources. This paper presents the formulation of a process of environmental character and self-sustaining from an energy point of view parameters to develop a process for the production of synthetic aggregate from fly ash and biomass fixed bed reactor. Thus, for the production of aggregate pellets were made from a mixture of clay, fly ash and charcoal in fixed proportions. The reactor is filled with 20% pellets (6.35 mm > pellet ≥ 4 mm) and 80% charcoal (3.36 mm > carbon ≥ 1.70 mm) rated for promoting the efficiency of combustion reactions and subsequent sintering process at different air velocities (Darcy at 20 °C) of 0.0059 m.s-1 (1º Experiment), 0.0098 m.s-1 (2º Experiment) and 0.017 m.s-1 (3º Experiment). By means of X-ray diffraction and scanning electron microscopy was identified the presence of mullite in synthetic aggregate. This material is characterized as lightweight aggregate, in accordance with current standards. With synthetic aggregates manufactured to lightweight concrete, according to the established standard, without structural function in civil construction, but with applications of moderate resistance and may be used in the counterfloor. The process if showed interesting for the sintering of aggregates with good adhesion to the matrix of cement, and can easily be controlled by composition, granulometry, temperature gradient and gaseous flow, reducing environmental impacts, to the extent that the material produced implies in not extraction of natural aggregates.