PURPOSE: To conduct the fractional recovery of high purity zinc, cadmium, and mercury from exhaust gas by simple equipment by setting the temperature of exhaust gas after the removal of dust with a difference given, lowering saturated vapor pressure, and condensing on the surface of a carrier.
CONSTITUTION: Dust in exhaust gas 1 containing iron oxide and lead oxide 13 as main components is removed by a dust collector such as a hot cyclone 2. Next, the exhaust gas 1 is sent to a contact zinc condensation apparatus 3, gas temperature at an outlet is controlled so that the saturated vapor pressure of zinc is lowered adequately, but the saturated vapor pressures of cadmium and mercury are not reduced, and a carrier 7 cooled in advance is allowed to fall to be contacted with the exhaust gas 1 so that condensation on the surface of the carrier 7 takes place. Next, a similar operation is conducted in a contact cadmium condensation apparatus 4 and a contact mercury apparatus 5. Thus, heavy metals are recovered from exhaust gas highly and in a high temperature and dry way.
FURUKAWA TAKESHI
SHIKADA TSUTOMU
UENO ICHIRO
ASANUMA MINORU
