Abstract
In order to develop a direct reduction process by fluidized bed, experimental operations of a pilot plant were carried out. The plant comprised multiple fluidized beds with both counter current and cross current contacting of ore and gas in a reactor of 25 cm inner diameter.
The results are summarized as follows.
1) Stable and sintering-free continuous operation at a maximum temperature of 900°C was carried out, using coarse particles of Hamersley iron ore (16-115 mesh) under pressure of 7 kg/ cm2G; the product of a reduction of above 95% was obtained, the utilization of hydrogen gas was 17%, and productivity was 55 t/m2d.
2) The distribution of fractional reduction in a fluidized bed was surveyed by magnetic separation of samples obtained from the bed. Reduction rate of particles in the bed was obtained directly from the distribution curve. An operation analysis was made on this information of particle reduction.
3) Operations using a partition plate designed by the authors were successful and effective to increase reduction of products and productivity.
