Mineral wastes are generated by the minerals, mining, and metal industries. These are generally inorganic waste streams of mainly waste rock or residues from refining during extraction of metals or minerals from the ore. There are many plants where minerals are recovered in secondany circuits, treating tailings, where the feed grades are much lower than would be economic on a mined ore. The world is now becoming aware of the finite nature of its resources at a price, and of the ever-increasing development costs of large new mines. Reprocessing of old tailings on a large scale must be worth examining very seriously by those with access to sufficient material of this type. In the present paper, mineral separation techniques to recover valuable metals and resources from the old tailings are reviewed, and new trends for future developments are also discussed.