| 摘要 |
<p>In a fluidized bed process for reducing iron oxide at a temperature of 1600-2000 DEG F. the reducing gas (CO + H2) is passed upwards at a rate sufficient to maintain the bed as a dense phase above the temperature of softening of a portion of partially reduced solid particles contained therein, fine particles of iron oxide being supplied to the bed at a rate such that said portion is only a minor amount of the total solid present therein at any time and as the partially reduced particles soften they agglomerate and are withdrawn as a product containing at least 80% of the original iron oxide in the metallic state. The reducing gas may be produced in the reducer by blowing in an oxygen containing gas and a hydrocarbon fuel both of which may be preheated and in the examples the gas is recycled. The preferred fluidizing gas velocity is 0.15-3 metres per second. The recycling of the smaller product particles to act as nuclei for further agglomeration in the bed is also referred to. Powdered flux (e.g. limestone or CaO) may also be included in the bed.</p> |
