| 摘要 |
<p>PURPOSE:To suppress the amt. of the by-product sulfuric acid and the waste slag to be produced and to perform selective sulfatization by adding solid fuel to zinc-leached slag, blowing the same into a fluidized roasting furnace, and introducing the gaseous mixture composed of the smelting waste gas contg. an adjusted amt. of SO2 and oxygen into the furnace. CONSTITUTION:Granular fuel and pyrite of 5-20wt% of zinc-leached slag are added to hydrous filter cake consisting of the zinc leached slag under agitation. The slurry thereof is ejected with high-pressure gas or the like into the fluidized bed of a fluidized roasting furnace. A gaseous mixture of smelting waste gas contg. SO2 and oxygen is introduced in the furnace to maintain the fluidized bed. The amt. of the solid fuel in this case is adjusted to the amt. enough to maintain 650-700 deg.C suitable for selective sulfation of Zn, Cu and Cd in the zinc-leached slag. The total amt. of oxygen in the gaseous mixture is so adjusted that the concn. of O2 in the waste gas from the fluidized furnace is made >=1 times of the concn. of the SO2 after oxygen is consumed for sulfation reaction and combustion. The valuable metal in the leached slag is converted efficiently to a water-soluble sulfate by the above-mentioned treatment.</p> |
