Operation in an integrated steel making plant, such as the processing of iron ore by blast furnace result in several wastes that need to be conveniently disposed to avoid environmental pollution. In the case of sludge wastes, a feasible solution is their addition to clayey ceramics. The objective of this work was then to characterize a steel making plant waste was subjected to mineralogical, chemical and physical tests. The combustion gases: CO, CO2, NO and SO2from thermal emission were analyzed. It was found that the blast furnace sludge has a high content of both iron and carbon. Its combustion generates enough heat to sensibly contribute to the firing of the ceramic, which is an energetical advantage associated with the sludge waste addition. The gas emission was monitored and, for relatively small addition of waste, no harm is apparently caused to the environment.