LAUSR

Abstract In this research, the impact of trivalent oxide nanoparticles on the microstructure and performance of the magnesite-dolomite refractory bricks was examined. Up to 4 wt% Fe 2 O 3 , Al 2 O 3 , and Cr 2 O 3 nanoparticles were added to the specimens as additives. Physical and mechanical properties such as bulk density (BD), apparent porosity (AP), hydration resistance (HR), and cold crushing strength (CCS) were examined. XRD and SEM analysis were used to detect the ceramic phase's formation and microstructure analysis, respectively. Results show that the use of Fe 2 O 3 , Al 2 O 3 , and Cr 2 O 3 nanoparticles improve the physical and mechanical properties of the MgO-CaO materials. Also, it revealed that specimens contain Fe 2 O 3 and Al 2 O 3 nanoparticles improve hydration resistance through the liquid phase sintering mechanism by formation some low melting phases such as C 2 F(2CaO·Fe 2 O3), C 3 A(3CaO·Al 2 O 3 ), and C 12 .A 7 (12CaO·7Al 2 O 3 ). However the specimens contain Cr 2 O 3 nanoparticles improve the hydration resistance through the solid state sintering mechanism by formation phases such as CaCr 2 O 4 and MgCr 2 O 4 . In general, hydration resistance improvement trend of the MgO-CaO specimens includes trivalent nanoparticles is Al 2 O 3 2 O 3 2 O 3 .