Practical Implications of the Physical Chemistry of Zinc-Lead Blast Furnace Slags

AbstractThe solubilities of zinc, lead, copper and sulphur in slag in the commercial operation of the zinc-lead blast furnace are considered in the light of the known thermodynamics of the relevant systems and the possible control of metal losses is assessed. Recent years have seen a gradual change from the use of high basicity slags to those with much lower lime-silica ratios where theory predicts a higher equilibrium zinc content. In practice, due to a lower slag volume and improved gas-slag contact a higher overall recovery of zinc is obtained. Future operations are likely to emphasize the role of the furnace as a combined zinc-lead-copper producer and consideration is given to the influence of the copper content of lead bullion on the copper solubility in slag. The twenty years of commercial operation of the zinc-lead blast furnace has proved it to be extremely flexible in terms of slag composition. Resume A la lumiere des proprietes thermodynamiques connues des systemes pertinents, nous avons analyse...