Rhenium metallurgy and recycling

Rhenium is a metal whose consumption depends on demand from the aerospace industry and its use in petroleum catalysis. It makes superalloys highly resistant to high temperatures and corrosion.

Its status as a strategic metal means that all economic data concerning it are estimates only. However, producers' estimated capacities are unlikely to keep pace with rising consumption, and supply crises are likely, since rhenium is a by-product of the extractive metallurgy of molybdenites from copper-bearing porphyries and kupferschiefers. It can therefore only be recovered from the washing solutions of roasting gases from molybdenite concentrates, or, secondarily, from copper concentrates.

Rhenium recovery processes are pyro-hydrometallurgical, and the end product is ammonium perrhenate. The metal is obtained by reduction of the perrhenate.

Although data on the fate of rhenium contained in spent reforming catalysts, alloy scraps and other rhenium-containing compounds is incomplete and very partial, recycling from these secondary sources can be considered almost total, given its high cost and scarcity.