A method for the direct reduction of iron oxides in a shaft furnace

摘要

A method for the direct reduction of iron oxides by passing the burden downwardly through pre-reduction 10 and metallisation 14 zones of a shaft furnace 1 while passing fuel gas produced by external partial combustion upwardly in a counter current manner in the pre-reduction zone 10 and passing reducing gas downwardly in a co-current manner through the metallisation zone 14. The flow of reducing gas is an independent flow that has not been subjected to external combustion. An intermediate zone 12 and 13 forms a narrowed throat 13 between the pre-reduction and metallisation zones 10 and 14 with the reducing gas being introduced such that passage of fuel gas from the pre-reduction 10 to the metallisation zone 14 is inhibited. Preferably about 5-10 volume % of the reducing gas passes upwardly from the intermediate 12 and 13 to the pre-reduction zone 10.