Cerâmica vermelha a partir de lodo galvânico, lodo de anodização do alumínio e areia de fundição

Abstract

The main objective of this study is to develop a ceramic composite and laboratory technology for the production of building materials with higher percentage of galvanic sludge, aluminium anodizing sludge, foundry sand and clay Taguá. The bodies of proof (CPs) were made with 20 g and 16 g in 20 x 60 mm mould and with uniaxial press of 10 MPa. The CPs were sintered at temperatures of 900, 950, 1000, 1050, 1100, 1150, 1200 and 1250° C for 6 hours. Density analyses were performed, fire loss, FRX, DRX, SEM/EDS, TGA/DSC, linear firing shrinkage, water absorption, flexural strength and leaching in order to characterize raw materials and developed ceramic material. The concentration of these residues, that were used as raw materials, varied in the following boundaries: galvanic sludge 0-10%, aluminium anodizing sludge 0- 75%, 0-20% foundry sand and clay Taguá of 0-80%. The values of flexural strength in composition 1 were 900 °C reached 5.87 MPa and 1250 °C reached 12.99 MPa, and composition 7 to 900 °C – 1.40 MPa, and 1250 °C – 26.82 MPa. SEM to the temperature of 900 °C showed the interaction of particles is mechanical and to the one of 1250 °C exhibited the cohesive interaction and clay fusion produced a material similar to glass. The results of the leaching indicated that the ceramic materials after sintering showed traces of Pb, Cu, Al and Fe, having immobilised just part of heavy metals present in the composition, which classifies it as hazardous waste. In comparison with the Brazilian standards, resistance aspect met the requirement for use in ceramic blocks for structural masonry in categories A, B and C, and solid bricks for masonry, respectively, however, the immobilization of heavy metals requires adjustments to achieve an environmentally friendly ceramic material.