Influence Of Reduction Temperature On Prereduction Of Iron Oxide With Coal Carbonisation Gas Without Tar

The fundamental study on prereduction of iron oxide was carried out in order to investigate the conditions for efficient use of the volatile matter in coal in an iron bath smelting reduction total process. At a rate of 200 K h(-1) under rising temperature conditions up to 1273 K, 1 kg of non-coking coal having 37 mass-% volatile matter was carbonised. Subsequently, this gas without tar reduced 2 kg of iron oxide pellets packed in a separate reactor at various temperatures between 673 and 1273 K. The fractional reduction F increased linearly from 0.07 to 0.25 at the reduction temperatures up to 1073 K, beyond which F increased more than the linear relation, such as F=0.35 at 1173 K and 0.43 at 1273 K. This may be due to the contribution of hydrocarbons to the reduction reaction at high temperatures. The hydrogen reduction accounts for about half of the fractional reduction. The mass of filtered tar occupied a mass of about half of the volatile matter released during coal carbonisation. This implies that more fractional reduction can be obtained when the tar is used in the process.