Continuous sponge iron prodn. in shaft furnace - using scrubbed recycle gas, part of which is passed through a gas generator

摘要

In a continuous sponge iron prodn. process, CO2 and H2O are removed from the furnace exhaust gas which is then split into at least two streams. One stream is passed into a gas generator where it is heated by a plasma burner and injected with an oxidant and a solid reductant to form a gas mixt. comprising mainly CO and H2. This gas mixt. is held at a temp. such that the ash content of the solid reductant forms a slag, is mixed with at least one of the other gas streams to adjust its temp. to that required for iron oxide redn. in the furnace, and is then injected at the bottom of the furnace. The oxidant is pref. water and the reductant is pref. coal. The ash content of the coal forms a slag which is easily removed so that problems of ash deposition in the installation are avoided. The hydrogen content and the temp. of the final reducing gas are controlled to the required values.