2001 Volume 87 Issue 5 Pages 290-297
For increase of sinter productivity, it is important to design sinter mixture granulation methods of moisture content, moisture distribution, and mixing method.
In order to design them, especially moisture distribution and its transformation with mixing, laboratory granulation tests were carried out. These tests were moisture absorption rate for a coarse iron ore (4-6 mm), adhesion of low moisture content fine iron ore (-0.25 mm) and one pseudo-particle coated with high moisture content fine ore, and granulation of coarse and fine ores with varying initial and adding moisture distribution and mixing method with a drum mixer and a high speed agitating mixer.
The main results obtained are as follows:
( 1 ) It took over 5 h to absorb moisture to coarse ore surrounded by raw sinter materials with 6 mass% moisture.
( 2 ) When adhering low moisture content fine to pseudo-particles coated with high moisture content adherent fine ores, final moisture content of total adherent fine converged to a constant value.
( 3 ) With mixing by a drum mixer, high moisture content fine adhered first to coarse. Next, low moisture content fine adhered to the coarse coated with high moisture content adherent fine. Then, pseudo-particle size distribution depended on moisture distribution of fine as well as ratio of coarse and fine. Pseudo-particle size distribution was sharper, when moisture distribution of fine was sharper and ratio of fine was lower.
On the other hand, with mixing by a high speed agitating mixer, moisture distribution of fine went homogeneous before adhering. This result suggests that adhering and collapse occurred at a same time. With mixing by a drum mixer after mixing by a high speed agitating mixer, pseudo-particle size distribution was sharpest.