Incorporation of river silt in ceramic tiles and bricks

Abstract

The aim of this work is to evaluate the effects of incorporating river silt originated from washing silica sands extracted in “Ria de Aveiro” as a raw material in the manufacturing process of traditional ceramic building products such as bricks and tiles and on their final properties. The solid river silt waste was physicochemically characterized for particle size distribution, morphology and XRF. The thermal behaviour was investigated by DTA and TGA analysis, and the mineralogical phases were identified by XRD. Testing bars made of several compositions incorporating amounts in the range of 0 to 10-wt% of river silt and of an industrial standard paste were produced in a pilot-plant extruder, and fired at different temperatures in the range of 950-1100 °C. The characterisation results of sintered specimens (water absorption, linear shrinkage and mechanical bending strength) have shown that products with final properties similar to those obtained from the standard industrial body could be achieved from a composition incorporating up to 5 wt.% of river silt waste.