Iron Making
The basic raw materials for iron making, i.e. iron ore, coal and fluxes, are sized to meet process requirements before being delivered to the iron plants.
These are blended in the correct proportions and fed to each of the pre-reduction kilns. Each kiln is fired with pulverized coal, the burner being located at the charge end of the kiln. Air fans, installed at intervals along the length of the kiln, inject air through pipes to burn the coal volatiles. The waste gases emitted from the kilns are cooled by water sprays in a conditioning tower and then cleaned in electrostatic precipitators.
The hot pre-reduced charge leaving the kilns is hoisted in refractory - lined containers to the charging floor, which is above the closed-top electric smelting furnaces. The smelter furnaces each have three self-baking electrodes whose movements are hydraulically controlled , two separate tap holes and tap hole guns. Wet gas scrubbers installed on each furnace clean the gas generated during the smelting operation. It is then collected in a gas holder and used as fuel for heating purposes in the works.
| Number of Pre-reduction Kilns | 13 |
|---|---|
| Length | 61m |
| Diameter (inside shell) | 4m |
| Rotating Speed (variable) | 0.40rpm to 1.25rpm |
| Nominal Furnace Rating | 6 x 350t and 1 x 600t per day |
| Transformer Rating | 4 x 45MVA, 1 x 63MVA, 2 x 33MVA |
| Furnace Diameter (inside shell) | 6 x 14m and 3 x 15.6m |
| Normal Power Input per Furnace | 6 x 24MW and 1 x 36MW |
| Tap to Tap Time | 3.5 to 4hrs |
| Tap Weight | 70t |