EXPERIMENTAL STUDY ON PREPARATION OF SLAG FIBER FROM BLAST FURNACE SLAG AND FLY ASH

In this paper, On the basis of calculating the liquidus temperatures and viscosities of the slag system CaO-SiO₂-Al₂O₃-MgO-FeO-Na₂O-K₂O, slag fiber was successfully prepared from blast furnace slag and coal ash by the high-speed air-injection method. The effect of factors such as mass ratio of blast furnace slag to coal ash (slag/coal), air-injection temperature and pressure was investigated in detail. While the air-injection experiment was carried out at 1450 ℃, the slag/coal was increased from 20% to 60%, the diameter of the slag fibers was subsequently decreased from 18.08 μm to 6.03 μm. the slag/coal was increased from 60% to 80%, the average fiber diameter was between 5 and 7 μm and the single fiber average tensile strength was about 1085 MPa. However, the glass beads, otherwise fibers, have been prepared if further increased the slag/coal. Hence, high quality mineral wool fibers could be obtained by controlling the addition ratio of the blast furnace slag between 60% and 80%, and the air-injection temperature between 1400 and 1500 ℃.