AN INVESTIGATION OF THE SLAG-FORMING PROCESSES IN AN 11M~3 BLAST-FURNACE SMELTING PANG-CHIA-PAO IRON ORE

From the results of thermodynamic calculations and petrographic examination, it has been found that in an 11 m~3 blast furnace smelting Pang-Chia-Pao iron ore, rankinite always forms as the primary crystalline phase, or in parallel with dicalcium silicate. Rankinite subsequently reacts with calcium oxide to form dicalcium silicate and reacts with fayalite to form wollastonite. These reactions can be represented as follows:2(2FeO. SiO_2)+3CaO=3CaO·2SiO_2+4FeO,3CaO·2SiO_2+CaO=2(2CaO·SiO_2),3CaO·2SiO_2+2FeO·SiO_2=3(CaO·SiO_2)+2FeO.The reduction of fayalite is also discussed.