Improvement of Iron Ore Sintering Productivity by Redistributing Air Volume during Sintering Process

The air volume distribution is one of the important factors of iron ore sintering speed and sinter strength, which plays an important part in achieving a high sintering productivity. The sintering process can be divided into two stages at the time of over-wetting layer disappearance. Increasing the air volume before the over-wetting layer disappears (1st stage) can improve the iron ore sintering speed. Decreasing the air volume after the over-wetting layer disappears (2nd stage) is beneficial to increase the sinter strength. When the air volume is redistributed to the air volume of 1st stage accounting for 74.59% and the air volume of 2nd stage accounting for 25.41%, the productivity coefficient increases from 1.34 t/(m(2).h) to 1.46 t/(m(2).h) with an increase of 8.96%, and the tumbler index of sinter reaches 59.96%. The sintering combustion layer thickness of 1st stage increases and the sintering combustion layer thickness of 2nd stage decreases in variable air volume sintering process. The moving speed of sintering combustion layer in variable air volume sintering process is significantly greater than that of the benchmark sintering combustion layer.