The impact of ZrSiO4 nanoparticles addition on the microstructure and properties of dolomite based refractories

Abstract Dolomite base refractories have advantages such as high refractoriness, potential to produce pure steel molten, high alkaline corrosion resistance, and economical for consumers. However, application of these refractories has been limited due to their high potential to hydration with atmosphere humidity. In this research work, the impact of ZrSiO 4 nanoparticles addition on the physical, thermo-mechanical, mechanical, and microstructure of the dolomite base refractories is investigated. Also, XRD and SEM/EDX analyses were used for determining generated ceramic phases and microstructure evaluation, respectively. Up to 3 wt% ZrSiO 4 nanoparticles were added to the compositions. Compositions fired at 1650 °C for 4 h in an electrical furnace. The results showed that the bulk density (from 2.95 to 3.33 g/cm 3 ), cold crushing strength (from 352 to 393 kg/cm 2 ), and hydration resistance (from1.95 to1.16%) of the compositions were increased while apparent porosity was decreased (from 9.33% to 4.84%) by the addition of ZrSiO 4 nanoparticles. As well as, for compositions containing 2.5 and 3 wt% ZrSiO 4 nanoparticles flexural strength at 1200 °C is decreased due to the generation of high content low melting phases such as Belite (2CaO.SiO 2 ), Diopside (CaO.MgO.2SiO 2 ),Akermanite (2CaO.MgO.2SiO 2 ), and Monticellite (CaO.MgO.SiO 2 ) at the firing process temperature. Finally, based on the obtained results and its relationship with the microstructure and properties the amount of2 wt% ZrSiO 4 nanoparticle was determined as the optimum content.