| 摘要 |
<p>1288442 Extracting and refining iron SVENSKA KULLARGERFABRIKEN AB 14 April 1970 [16 April 1969] 17775/70 Heading C7D Scrap iron is pre-heated and then melted, or iron ore is pre-heated reduced and melted, in a twin hearth furnace, each hearth alternately operating as a pre-heating and then as a melting furnace. The bath is then transferred to a converter for refining, and subsequently to a ladle having an austenitic steel shell, or may be transferred directly to the ladle. After slag removal either a vacuum cover or a cover carrying electrodes is placed on the ladle, and the bath inductively stirred while being refined, alloyed and/or heated. The twin-hearth furnace may have cover-mounted burners for pre-heating and cover mounted electrodes for melting, while when ore is to be reduced hot reducing gases from the hearth operating in the smelting mode are passed through the ore in the other hearth.</p> |
