IRON ORE REDUCTION METHOD AND INSTALLATION THEREFOR

The invention concerns a method for iron reduction to make sponge iron which consists in: depositing a feed of iron ore on a grate and moving the grate so as to cause the feed to pass in at least three different zones; inputting gases, called input gases into one or several zones, including a hot gaseous carbonaceous reducing agent, and forcing said input gases through the ore located on the grate; and capturing the gases resulting from said forced passage, called output gases. The passage of the input gases brings the ore to a temperature ranging between 850° C. and 1300° C.; maintaining said feed at said temperature until an iron ore metallizing rate ranging between 60% and 100% is obtained. The feed deposited on the grate consists of either iron ore calibrated between 5 mm and 40 mm, or iron ore pellets having a diameter ranging between 5 mm and 20 mm, or iron ore granules of size between 2 mm and 10 mm, and the thickness of the deposited layer ranges between 150 mm and 600 mm. The flux of input gases, through the feed deposited on the grate, is directed from up downwards and generally obtained by generating beneath the grate an under-pressure ranging between 500 and 200 of water column. The forced flow of input gases through the feed in at least one processing zone consists at least partly of the output gas captured under the grate, said output gas captured under the grate having been at least subjected to a treatment such as scrubbing, desulphurization, drying, dust extraction, reheating and carbonate removal.