Metal ores are complex mixtures of compounds and several steps are used to obtain the respective metals from them. Pyrometallurgical, hydrometallurgical, or electrolytic methods are used to extract the metals from the ore and to refine them depending on the end-use requirements. These steps involve generation of wastes in large quantities whose properties and hazardous nature vary considerably. With increasing environmental awareness and rising disposal costs, these wastes are being seen as raw materials for other applications. In this chapter, the status of use of wastes generated from different metal industries is discussed and the trends in research in this area are presented. In case of wastes such as slag where utilization levels are high, the current common applications are covered. However, for wastes like red mud, the focus is more on literature studies since the utilization levels are still low and many exploratory studies on their use are underway.