| 摘要 |
<p>1. Use of a muffle furnace for zinc removal from oxide-containing zinciferous iron sources such as, for example, iron ores, mill waste, in particular mill dust, comprising introducing the iron source in lumpy form having a minimum grain size of 5 mm together with lumpy reducing agents into the muffle furnace being heated exteriorly, the charge travelling, between the supply end and the discharge end of the muffle furnace, through a pre-heating and a pre-reduction zone as well as a reaction zone, the muffle furnace being adapted to be closed in a gas-tight manner at its supply and discharge ends, the wall of the muffle furnace being provided with gas outlet openings in a zone located between said ends of the muffle furnace, said gas outlet openings bypassing or passing through heating means externally mounted on the muffle furnace, said heating means being formed by at least two combustion chambers externally surrounding the muffle furnace and arranged one above the other in the axial direction thereof, conduits arranged between adjacent combustion chambers being connected to the gas outlet openings of the muffle furnace, and the cross-sectional plane of the gas outlet openings lying at a zone of the muffle furnace having a temperature of more than 650 degrees C, preferably 700 to 900 degrees C.</p> |
