Reduction of Silicon in Hot Metal by Iron Ore and Flux Injection through Blast Furnace Tuyere

Abstract

A Multi-Purpose Injection (MPI) System was installed at Chiba No. 5 blast furnace and a test operation on the injection of iron ores and fluxes was conducted twenty one days for the purpose of lowering silicon content in hot metal. The results obtained from the trial are summarized as follows:
1. Reduction of silicon content of 0.08% in hot metal was obtained by the mixed powder injection of iron ore and flux powder of 5.0 kg-CaO/t. It was suggested that the major factor inducing the silicon reduction was the absorption of SiO(g) by the injected powder. That was made on the basis of sampling examination by a sideways tuyere probe.
2. Significant reduction of silicon content was not observed during the iron ore powder injection up to 50.4 kg/t with constant coke rate. On the other hand, increases of (FeO) and [S] indicated that the oxygen potential in a hearth became higher by the iron ore powder injection.