To reduce and recover metals from metallic sludge and the like with good thermal efficiency with a simple device by cooling the metal vapor-contg. gases from a smelting reduction furnace with the metallic sludge and the like as a refrigerant to deposit metals.
High-temp. air is blown into the vertical type smelting reduction furnace 1 packed with carbonaceous materials, such as coke, from its tuyeres 4, 5 of upper and lower stages to burn the coke and to form the reducing gases. The dried metallic sludges 50 blown from the tuyere 4 of the upper stage are reduced and are discharged as metal vapors from the furnace top. These vapors enter a cooling and dust removing vessel 9. The metallic sludges 50 enter the cooling piping 10 in the cooling and dust removing vessel 9 and are heated and dried by the hightemp. metal vapors from the vertical type smelting reduction furnace 1 and thereafter, the metallic sludge and the like are supplied as the high-temp. dry metallic sludge and the like into the vertical type smelting reduction furnace 1 where the metallic sludge and the like are reduced to the metal vapors. On the other hand, the metal vapors are cooled by the cooling piping 10 using the metallic sludge and the like 50 as the refrigerant and are deposited as the solid metals. These metals are recovered into a hopper 16.
ISHIWATARI NATSUO
HARA YOSHIAKI
ITAYA HIROSHI
Next Patent: METHOD FOR RECOVERING VALUABLE MATERIAL FROM SECONDARY FLY ASH