Sintered Iron-Ore Manufacturing Capabilities when Using Combined Fuel

Abstract

In order to create thermal conditions that form the same time-temperature conditions throughout the height of the sinter-feed mixture after (1) blending, (2) source material pelletizing, (3) laying on the fire grate, (4) initial layer heating under the ignition hood, and (5) ignition of the solid charge fuel, a natural gas-air mixture with an air flow coefficient > 3.5 is supplied to the sinter-feed layer through a gas-air distribution device (GAD), and is then heated while passing through a hot upper sinter layer to the ignition temperature (450–600°C) with the gaseous fuel formation at 1100–1150°C in the 40–60 mm active burning-zone layer. The heat released in this process provides additional heating of the upper layer horizons to the required sintering charge material temperature. GAD design tests using an AK–50 sintering machine showed equalization of the redox conditions and a decrease in the yield of small sinter fractions in the drum sample, which improves the sintering machine productivity by 30–35% with an efficient fine coke consumption of 2.5–2.9%. When switching to sinter by using combined fuel, the blast furnace productivity increases by 10–14%, and the specific fuel consumption in coke per unit of iron made decreases by 8%.