| 摘要 |
<p>PURPOSE:To evaporate and remove easily harmful components and to recover efficiently and inexpensively valuable metals by adding a carbonaceous solid fuel to special steel dust and sludge, lumping the mixture, subjecting the lumps to self combustion in a reduction roasting furnace and roasting the same to a red hot state. CONSTITUTION:The reducing agent contg. the carbonaceous solid fuel and if necessary a binder are added to the special steel dust and sludge and the mixture is kneaded and molded to lumps 1 having a prescribed size. The lumps are charged from a charging hopper 2 into the reduction roasting furnace 4. The above-mentioned carbonaceous fuel is ignited to burn of itself in a lower roasting zone 7 to roast the lumps 1 to the red hot state. The harmful components such as Zn, Pd and Cd contained therein are thereby reduced and evaporated away and the valuable metals such as Ni, Cr and Fe are converted to a reduced metal without melting. The reduced metal is recovered into a hermetic container 17 through an opened lower fire grate 9. Said metal is charged in the non-reoxidizing state into a metallurgical furnace (not shown), by which the above-mentioned valuable metals are recovered. On the other hand, the evaporated components are sucked and recovered by a dust collector (not shown).</p> |
