METHOD OF TREATING LEACHING RESIDUES FROM THE HYDROMETALLURGICAL PRODUCTION OF ZINC

摘要

1485911 Recovery of metal values from leach residues DET NORSKE ZINKKOMPANI A/S 19 March 1975 [21 March 1974] 11458/75 Heading C1A [Also in Division C7] Lead and zinc are recoverable from leaching residues (as defined) and optionally iron rich precipitates (as defined) which contain zinc as one or more compounds selected from its sulphides, sulphates, oxides and ferrites and lead as one or more of its compounds selected from its sulphides, sulphates or ferrites, by a method comprising (a) heating the material in the presence of slag within the temperature range 900‹ to 1350‹ C. under an oxygen partial pressure exceeding the oxygen partial pressure defined by the equation whereby lead oxide is formed and (b) thereafter treating the material with a reducing agent to reduce lead oxide to molten lead at an oxygen partial pressure not exceeding the value defined by the equation and not exceeding the value defined by the equation and not less than the value defined by the equation a pbo in Equation (II) representing the activity of lead oxide in the slag and T in Equations (I) to (IV) representing the temperature in degrees Kelvin, whereby said one or more zinc compounds are reduced to elemental zinc which is vaporized.