Most rhenium is a by-product of the copper industry.
Rhenium is found in copper ore that is contaminated with molybdenum, in a form of sludge that is sulfurous. Step are taken to roast this sulfurous mixture at extremely high temperature, to form molybdenum oxide, releasing the rhenium and it can be collected and then concentrated in units. High purity forms may be in powders, chemicals, or fabricated materials. This process is completed in the U.S., in such states as Florida, Arizona, and else where in the Arizona region as well as Utah. Rhenium is widely used for filaments foe mass spectrographs and ion gages.