Effect of isothermal and cooling rate on crystallization and viscosity of silicomanganese waste slag

In order to explore the manufacturing process of mineral wool, the effects of isothermal temperature and cooling rate on the crystallization properties of silicomanganese slag were in-situ observed by using a confocal laser scanning microscopy (CLSM). In addition, the relationship between different cooling rates and the viscosity of silicomanganese slag was studied by a viscometer. The results show that the crystallinity of silicomanganese slag increases with the decrease of temperature in the range of 1325?1225 ?C. At the same time, with the decrease of temperature, the crystallization mechanism of silicomanganese slag changes from two-dimensional to onedimensional. Once the cooling rate is greater than 5 ?C/s, the silicomanganese slag is glassy and will not precipitate crystals. The SEM images of the precipitated phase morphology of silicomanganese slag are consistent with the in-situ observation results of CLSM experiment, and the isothermal crystalline phase is anorthite. Moreover, the viscosity test shows that with the increase of cooling rate, the viscosity of silicomanganese slag decreases obviously at 1400 ?C.