Wetting behavior between fayalite-type slags and solid magnesia

The wetting behavior of single-crystalline magnesia (MgO) by fayalite-type slag melts has been studied by the sessile-drop technique, which incorporates high-temperature X-ray radiography. The experiments have been performed under oxygen partial pressures of 106 and 104 Pa at a temperature of 1473 K. The mass ratios of iron to silica, Fe/SiO2, in the slag that has been used are 1.44 and 2.05. Infiltration behavior of a fayalite-type slag into MgO are discussed, based on the experimental results that involve wettability and surface tension. Two phases—magnesio-wustite and olivine—are observed at the interface. Interdiffusivity in the magnesiowustite solid solution has been determined as a function of the iron oxide content. To investigate the interfacial reaction, experiments that use high-density MgO crucibles also have been conducted. Phase relations between the magnesiowustite and the olivine, and the rate of growth of the phases, are discussed.