The observed results has been correlated the aggregates type, morphology, (size, shape and distribution). Although the alumina aggregate substitution showed a negligible variation in the physical properties of the Al2O3-C refractory it shows a substantial effect on the mechanical and thermo-chemical properties. Physical properties like apparent porosity (AP) and bulk density (BD), mechanical properties like cold modulus of rupture (CMOR), cold crushing strength (CCS), and modulus of elasticity (MOE), thermal expansion coefficient (TEC) and thermo-chemical properties like oxidation resistance and erosion resistance were studied as a function of alumina aggregate (amount and type) of the fired (10500C for 3 hr) Al2O3-C refractory samples. Different Al2O3-C refractory formulation were prepared by varying the alumina aggregates (types) and amount keeping total alumina aggregate, fused silica aggregate, graphite and binder unaltered. Phenolic resins were used as binder to bind the different aggregates of the Al2O3-C refractory formulation. Fused silica has been incorporated into the Al2O3-C composition in order to provide low thermal expansion coefficient of the Al2O3-C refractories. Flakey graphite has been used as a source of carbon. White fused alumina (WFA), brown fused alumina (BFA) and tabular alumina (TA) have been used as a source of alumina. The effect of alumina aggregates on the physical, mechanical, thermal and thermo-chemical properties of Al2O3-C has been systematically studied in this present investigation. In addition, the characterization was completed by evaluating the mechanical properties at room temperature, such as the mechanical strength and Young׳s modulus.Īlumina-carbon (Al2O3-C) refractories are extensively used for steel making application particularly for continuous casting of steel owing to its high modulus of rupture and high cold crushing strength, low thermal expansion coefficient, high thermal conductivity, high thermal shock resistance and resistance to molten slag and metal. The results of these different techniques were analyzed separately and together in order to obtain a detailed description of each refractory in relation to its physical and chemical characteristics and thermal evolution. In the present work, several complementary techniques were used in combination: X-ray fluorescence, plasma emission spectroscopy, gravimetry, X-ray diffraction, differential thermal and thermogrametric analyses, reflection optical microscopy and scanning electron microscopy, density and porosity measurements, dilatometric analysis and permanent linear change measurements. The variety of components, be they oxidic, metallic or polymeric in nature, and the complexity of the final microstructure and texture make characterizing these refractories a difficult task. AMC bricks comprise different amounts of alumina, sintered or electrofused magnesia, graphite and antioxidant additives bonded together with a phenolic resin. These results are essential for the study of the chemical and mechanical behavior of these materials, which the present work frames. In this paper, the methodology implemented for the physical, chemical and thermal characterization of AMC refractories is presented along with the obtained results.
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