| 摘要 |
<p>Iron ore is reduced directly to pure molten iron in a continuous process. The crushed and magnetically separated material is preheated in a fluidised bed at 850-900 degrees C, where sulphur is removed. Two further fluidised beds at 700 degrees C reduce the remaining Fe2O3 to Fe and FeO. This mixture passes into the main cyclone furnace where it reacts with a mixture of H2 and CO at 1000 degrees C, granulated limestone being fed in as a flux. The remainder of the FeO is reduced to Fe and the liquid iron collects on the hearth of the electric furnace underneath, which is integral with the cyclone. P and Si are removed in the slag and the pure iron is topped off, either intermittently or continuously. The cyclone waste gases, containing H2, H2O, CO and CO2, pass through a heat exchanger and are then cleaned and reconstituted with methane to form H2 and CO for reuse in the cyclone. Removal of sulphur prevent sticking in the cyclone furnace, where the reduction is relatively rapid.</p> |
