The Countercurrent Reduction of Sinter and Carbon Deposition

Abstract

The reduction tube which had a slit-typetuyere was used for the countercurrent reduction. The data of countercurrent reduction were plotted on the graph of the degree of reduction v. s. the gas utilization coefficient. This graph was advantageous to explain the countercurrent phenomena.
On the countercurrent reduction of sinter, the gas utilization coefficient was depended on two factors; the first was a ratio of ore descending speed to gas flow rate and the second was a contact time. When the contact time was 8.5 sec, the H₂ utilization coefficient was similar to that of CO, but when the contact time was shorter, the former was larger than the latter.
With the countercurrent reduction by CO, carbon deposited fast when a ratio of are descending speed to gas flow rate was low and a contact time was long. And with that by N₂+34% CO, carbon deposited little.
The reduction velocity with N₂+34% CO was mainly determined, between 600°C and 900°C.