Determination of Al ₂2 O ₃3 Activity by Reference Slag Method in CaO–SiO ₂2 –Al ₂2 O ₃3 –MgO Melts for Blast Furnace Slag with High Al ₂2 O ₃3 at 1873?K

摘要

> With the increase in using high Al ₂ O ₃ iron ore, the content of Al ₂ O ₃ in blast furnace slag has increased sharply in recent years. Thus, the activity of high Al ₂ O ₃ slag in the blast furnace slag system needs further study. Herein, the activity of Al ₂ O ₃ ( a ( Al 2 O 3 ) ) in CaO–SiO ₂ –Al ₂ O ₃ –MgO slag equilibrated with molten Cu at 1873?K is determined by applying the reference slag method. Isoactivity contours for Al ₂ O ₃ in the (CaO?+?MgO)–SiO ₂ –Al ₂ O ₃ pseudoternary system are achieved for blast furnace slag, and the effects of R (mass% CaO/mass% SiO ₂ ) and MgO/Al ₂ O ₃ on the activity of Al ₂ O ₃ are discussed. When Al ₂ O ₃ ?=?20?wt% and MgO/Al ₂ O ₃ ?=?0.4, with R increasing from 1.10 to 1.30, the activity of Al ₂ O ₃ decreases from 0.0423 to 0.0244. When Al ₂ O ₃ ?=?20?wt% and R ?=?1.25, with MgO/Al ₂ O ₃ increasing from 0.35 to 0.55, the activity of Al ₂ O ₃ decreases from 0.0470 to 0.0366. The reference slag method, herein, is feasible based on the experimental results and the reference slag method is simple, reasonable, and of high accuracy.