Study on the properties of periclase-forsterite lightweight heat-insulating refractories for ladle permanent layer

The heat dissipation of the ladle permanent layer is urgent to be tackled. Periclase has good compressive strength, high fire resistance, and high chemical stability. The thermal conductivity of forsterite is only 1/3–1/4 of periclase, which is low. Thus, the periclase-forsterite lightweight heat-insulating refractories for a permanent layer of steel ladle prepared from low-grade talc powder and light burned magnesia powder made by low-grade magnesite can well satisfy the requirements of the permanent layer. In this study, the effect of raw material ratio on as-prepared refractories was systematically investigated. The results demonstrated that with the increase in talc, the bulk densities of the samples decreased from 1.73 g/cm³ to 1.46 g/cm³, the porosities increased from 42% to 58%, and the compressive strengths decreased from 49 MPa to 28 MPa; besides, the thermal conductivities decreased from 1.062 to 1.22 W m^?1 K^?1 to 0.496–0.61 W m^?1 K^?1 with the increase in forsterite. Additionally, talc promoted the formation of intercrystalline pores, and the synthesis of forsterite in the experiment was dominated by the “Template growth” mechanism.