Recycling of steel sludge into red ceramic

The present paper has for objective to evaluate the effect of fine steel sludge waste incorporation on the properties and microstructure of a kaolinitic clayey body used to the fabrication of bricks and roofing tiles. Compositions were prepared with additions of waste of 0, 5 and 10 wt.% in a kaolinitic clay from the county of Campos dos Goytacazes, State of Rio de Janeiro, Brazil. To determine the technological properties such as bulk density, linear shrinkage, water absorption and flexural strength, specimens were prepared by uniaxial pressure at 20 MPa and then fired in a laboratory furnace at 700 degrees C, 900 degrees C and 1100 degrees C. The microstructure of the fired specimen was evaluated by SEM. The results showed that the incorporation up to 10 wt. % of fine steel sludge does not change the ceramic properties, specially, at low temperatures. Hence, the recycling of steel sludge into red ceramic fabrication can be considered as an environmentally correct solution for the final disposal of this type of waste.