Recovery of rhenium from molybdenum and copper concentrates during the Looping Sulfide Oxidation process

Rhenium is recovered during pyrometallurgical processing of molybdenum sulfide and copper sulfide ores; the traditional technology involves removing rhenium(VII) oxide, Re₂O₇, from the sulfurous gas phase generated during multiple hearth roasting (in molybdenum processing) and smelting (in copper processing). A new technology platform called Looping Sulfide Oxidation (LSO) has been proposed to produce molybdenum and copper using alternative process chemistries. A detailed thermodynamic study of the reaction conditions used in LSO process indicates that rhenium recovery is possible at higher rates than currently realized in the industry. Conditions at which Re₂O₇ is reduced to rhenium metal by S₂ have been identified and key process conditions are outlined to maximize performance of the LSO scheme and rhenium recovery.