Process and plant for purifying waste gases from aluminium melting processes

摘要

Exhaust gases from aluminum smelting processes having a melt phase and a chlorination, is blown into the chlorine gas into the melt, are cleaned by the hot exhaust gases cooled, then in a Hauptab gas circuit in a reactor with hydrated lime dust neutrali Siert and then through filters are directed to the separation of the solid components. To reduce the lime hydrate requirement and the attack of non landfillable solids is provided, that the hot exhaust gases are passed from the chlorination directly in a bypass circuit and at least one washing stage, are in which chlorine and chloride residues washed out of the exhaust gas, and that the purified exhaust gas is fed back into the main exhaust circuit, while the acidic drain water of the washing stage chemically neutralized and the neutralized water is vaporized by introducing into the main exhaust circuit upstream of the reactor, wherein the resulting solids were separated off on the filter from the exhaust gas.