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The present research work involved cleaning contaminated acid resistance refractory brick waste, i.e. that which was in direct contact with the furnace contents. The waste acid resistance brick was obtained from the sixth furnace of Misrata Iron and Steel Complex. The waste brick was crushed to 30mm size granules, and further ground by hammer milling to 1mm. The 1mm sized powder was sieved to give over-sized (+0.355mm) waste powder via (karl kolb Shaker). The over-sized powder (+0.355mm) was subjected to high-energy ball milling to produce nano-powder with particles sizes ranging from 45 to 51nm. Three powder batches were prepared. Each powder batch was made up of three components; brick waste nano-powder, coarse over-sized (+0.355mm) waste brick powder, and 75micron-sized local Sebha Kaolin clay. The weight % fractions of the nano-powder component were designated as N1 = 10, N2 = 20, and N3 = 30. The first powder batch was composed of 45% coarse waste brick powder, N1 waste nano-powder and 45% kaolin clay. The second and third powder batches had nano-powder fractions of N2 and N3 respectively; while each of the fractions of coarse waste powder and kaolin clay were 40and 35%.A11 powder batches had equal fractions of coarse waste powder and kaolin clay. That is the three powder batches had the compositions; 45:N1:45;40: N2: 40;and 35: N3:35. These powder batches were pressed, in a semidry state, at a pressure of 100 Pa. The powder batches were then dried at a temperature of 110°C before being fired at 1000, 1300, and 1500°C to produce rectangular, cylindrical, and disc shaped final products. Characterization of starting refractory waste bricks, waste coarse powder, Sebha kaolin clay, and waste nano-powder using the techniques of Energy Dispersive Spectroscopy "EDS", X-Ray Diffraction "XRD" and Scanning Electron Microscope "SEM" analysis was earned out. The work also involved the measurement of physical properties; bulk density, porosity, and volume shrinkage of waste bricks and sintered final products. The mechanical properties including cold crushing strength, and flexure strength, and thermal conductivity were also measured as a physical property. Melting of a glassy phase was observed at the firing temperature of 1500˚C for which the heating schedule involved increasing the temperature from room temperature to 600˚C in one hour. The specimen was held at 600˚C for 25 minutes and then its temperature increased to 1500˚C in 90 minutes. The sample was then held at 1500˚C for one hour and left in the furnace to cool to room temperature until the following day. The presence of this phase had a negative effect on physical and mechanical properties. Hence, based on the obtained results of the present research work, this limited the recommended maximum working temperature of the produced bricks to 1300˚C. The inclusion of 30% of nano¬sized powder particles as a component in the refractory powder batches had the most enhancing effect on the mechanical properties of cold crushing strength and flexure strength of the final shaped products fired at 1300˚C. A similar positive effect has also been observed for reducing thermal conductivity and the physical properties of bulk density, volume shrinkage, and porosity. This would mean that the most suitable refractory brick powder batch is 35: N3: 35 with the local Sebha kaolin clay playing the role as a good binding material.
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