Extraction of iron from copper-plant slag

In the production of copper from sulfide ore, slag accumulates at the processing plant. In the present work, the phase transformations that occur in such slag during its reduction by the gasification products of carbon at 1100 and 1200°C are investigated. Experiments show that most of the iron present in such slag may be converted to metallic form by the gasification products of carbon in cupola furnaces at 1100°C. Subsequent increase in temperature to 1200°C improves the extraction of iron. In the indirect reduction of slag at temperatures above its melting point, metallic iron is mainly concentrated at the outer surface of the product, forming large inclusions that are easily extracted by magnetic separation. An expedient approach is to reduce laminar batch consisting of slag layers no thicker than 5 mm and interlayers of ground coal. © 2016, Allerton Press, Inc.