Produção e caracterização da cerâmica vermelha com a adição de resíduos oriundos da lavagem da lã de ovinos

Abstract

The use of solid ash residue for the manufacture of ceramic products has been evidence to improve the chemical, physical and mechanical properties, minimizing environmental problems and reduce the volume of extraction clayey raw materials. In view of this, the present study aims to evaluate the possibility to make ceramics by the clay added by sheep wool waste ash, in different percentages. The purpose of this application is the construction bricks. The residue is derived from the beneficiation process of the sheep wool into a textile, and this was burnt at the air and sieved in a set of sieves 20, 30, 40, 60 and 80 mesh, only formulations were made containing clay and wool gray additions (CL) in percentages of 5, 10, 20 and 30 % in a red ceramic, being subjected to chemical characterization by X-Ray Fluorescence (XRF) and Fourier Transform in the Infrared Spectroscopy (FT-IR); Mineralogical with X-Ray Diffraction (XRD); Thermal by Thermogravimetric Analysis (TG) and Differential Scanning Calorimetry (DSC); through of physical and particle size distribution and physical indexes. The conformation of the samples was accomplished by pressing and vacuum extrusion. And the linear shrinkage by drying and heating, were also evaluated. The sintering of the ceramic products is performed at temperatures of 600, 700 and 800 °C with a the rate of 100 °Cmin -1 and three hours burning level. The structural properties of the products were performed by FT-IR and XRD, and the mechanical strength of the flexural breaking strain. Other physical analysis such as linear shrinkage drying, porosity, bulk density and water absorption were also evaluated. For mechanical strength average values obtained ranged from 0.38 ± 0.15 MPa to 6.70 ± 0.76 MPa and water absorption, the average value was 14.72 ± 0.39 % and 27.60 ± 1.05 % for the ceramics pressed. The evaluation of these same parameters for extruded ceramics, changed from 2.38 ± 1.47 MPa to 7.38 ± 3.00 MPa and 8.57 ± 0.68 % to 24.80 ± 1.08 %. The mechanical strength and water absorption values obtained in the best heating temperature to 800 °C. However, the values were lower than expected due to the extruded ceramic products present conditions as the “black core”.