摘要 |
<p>A method of processing flue dust that contains one or more compounds from a first group of zinc, lead and cadmium compounds, and contains iron compounds, involves heating the flue dust to cause a substantial portion of one or more of the compounds of the first group to become gas-borne. A carbonaceous material is introduced to the remaining flue dust, and the flue dust/carbonaceous material mixture is heated to cause a substantial portion of the remaining compounds from the first group to become gas-borne while retaining a substantial portion of the iron in a non-gas-borne condition. The gas-borne compounds are separated from the non-gas-borne compounds. The heating vessel is preferably a rotating cylindrical retort.</p> |