<Original Papers>The Reduction of SiO_2 from Molten Slag to Molten Pig Iron

The condition and mechanism of the reduction of SiO_2 from molten slag to molten pig iron were investigated by melting the slags of the ternary system, CaO-SiO_2-Al_2O_3,and pig or pure iron in the stream of CO or CO-N_2 gas in a graphite or magnesia crncible. The results were as follows : (1) The silicon content of iron increased with temperature at the same slag composition. (2) The silicon content of iron incresed with the lowering of basicity, (CaO)/(SiO_2), at the same temperature. (3) The reduction of SiO_2 increased with time. (4) The silicon content of iron increased with the dilution of CO gas with N_2 gas. (5) For the reduction of SiO_2,the following three reactions were considered. [chemical formula] It was found that [C] played the most important role among reducing agents, [C], C_ and CO_, that is the reaction (1) predominated