This study describes the characteristics of mineral wool and its applications, and also introduces the traditional process of mineral wool made from molten blast furnace (BF) slag. Compared with high energy consumption of the traditional process, the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag, and also reduce production costs. However, there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous. Based on the physical and chemical properties of the molten BF slag, the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted. Combined with the crystallization and phase diagram of slag wool, its heat resistance, water resistance, durability and corrosion resistance were analyzed. Finally, trends of the technology development are proposed.