Utilização de planejamento experimental no estudo para imobilização de lodo galvânico em cerâmica vermelha para minimização de impactos ambientais

Abstract

The proposed study aims to evaluate by means of statistical design, the incorporation of galvanic sludge (with highly polluting metals, such as chromium) in red ceramic, in order to reduce its storage and contamination to the environment and the mankind. The galvanic sludge and clay used were characterized by density measurement, visual characteristics, pH, moisture, total organic matter, amount of chromium, infrared spectroscopy and thermal analysis (TG/DTA). For evaluation of the ceramic production process it was performed a 23 factorial design (two levels and central points) where the independent variables were sludge concentration in the mass, drying temperature and fring temperature. The dependent variables were water absorption, chromium leaching, waste solubility and linear shrinkage, according to the established limits. Analyzing the obtained results in the characterization of the samples, it was possible to identify after checking with the current regulations, that there were two sludge concentrations in the mix which ft most of the compliances (5 and 15%), except for the solution test, in which all samples showed results above the allowed limit. The achieved results showed the possibility of developing ceramic products added with galvanic sludge, but in the ranges of independent variables studied, it was not possible the chromium inertization.