| 摘要 |
<p>1,129,994. Producing iron. G.K.N. STEEL CO. Ltd. Jan. 25, 1966 [oct. 28, 1964], No. 44009/64. Heading C7D. Iron e.g. sponge iron concentrate is produced from low grade ore containing clay by heating the ore under reducing conditions, e.g. at 1300- 1400‹C in a rotary kiln containing a CO atmosphere, to yield metallic iron, followed by cooling with or without wet ball-milling and then separation of the iron from the remaining residue e.g. using magnetic separators. Sufficient lime is added to the ore prior to the reduction heating to transform the SiO 2 and Al 2 O 3 of the clay on heating to dicalcium silicate and calcium aluminates, which fall to powder on subsequent cooling thereby facilitating the separation of the iron concentrate. The lime may be added by blending the crushed ore with powdered limestone, carbon e.g. coke breeze being also added in excess of that required for complete reduction. The separated iron concentrate, fabricated into, briquettes, may be used in a blast furnace (as scrap), an open hearth furnace or a converter.</p> |
