| 摘要 |
<p>The invention relates to a method for the thermal treatment of raw materials in which a furnace ( 2 ) is charged with the raw material and at least two gas phases are introduced into the furnace in which the raw material is subjected to the thermal treatment. The gas phases have different oxygen contents and are introduced into the furnace sequentially. During the introduction of a first gas phase with a relatively high oxygen content (for example, O<SUB>2</SUB>), a temperature and pressure rise occurs; the reaction gases are forced towards the center of the furnace by the subsequent introduction of a second gas phase with a relatively low or no oxygen content (for example, air, CH<SUB>4</SUB>), whereupon an equalization of temperature and concentration occurs in the melting zone. Said method permits a good penetration of the furnace charge and avoids localized overheating within the charge. The invention further relates to a furnace ( 2 ) for carrying out said method.</p> |
