| 摘要 |
A method and apparatus for the production of sponge iron, and preferably for the direct melting of the sponge iron in an electric arc furnace by the reduction of oxide containing iron ore, includes a preheating apparatus with a grate which is adapted to receive a charge of the iron-oxide containing ore. The ore is heated in the preheating furnace, in a neutral to oxidizing atmosphere, to the necessary reduction temperature and the hot gases for heating are advantageously admitted in a non-cocurrent flow, preferably in a counterflow manner. The preheated ore is subsequently reduced by directing it into a rotating tubular furnace which is advantageously tilted downwardly from its entrance end to provide for the discharge of the sponge material after treatment. While the ore is in the revolving furnace, it is reduced by blowing in a solid carbonaceous reducing agent at temperatures below the softening temperature of the furnace charge. The reduction temperature is maintained by blowing in fresh air at points distributed over the length of the reduction zone defined by the tubular furnace. The entire amount of the solid carbonaceous reducing agent or at least that required for the reduction of the ore is blown into the revolving tubular furnace from the same end at which the furnace is charged with the preheated ore. The furnace gases are conducted in the same direction as the ore and the reducing agent, and after use in the tubular furnace they are advantageously directed to a waste heat boiler for generation of steam for supplying power to the electric melting furnace. High volatile coal is preferably used as the reducing agent.
|
