Molybdenum roaster off-gas is scrubbed and precipitated as ammonium perrhenate (NH4ReO4), which is reduced with hydrogen at ~500 °C to Re metal powder.
Research Elements Re · atomic number 75 Transition metal · period 6, group 7 [Xe] 4f14 5d5 6s2 Shells: 2, 8, 18, 32, 13, 2 Valence electrons: 2 in the outer shell (6s2), and 5 in 5d5 Green dots are the outer shell's s and p electrons. Softer green dots are the d electrons of transition metals, and the d and f electrons of lanthanides and actinides: they often take part in bonding, but not always. Grey dots are the core. Ground-state configuration from the NIST Atomic Spectra Database (A. Kramida, Yu. Ralchenko, J. Reader and the NIST ASD Team). Abundance is the mole fraction of the element found as that isotope on Earth; digits in parentheses are the uncertainty in the last digits. Masses and abundances from NIST, Atomic Weights and Isotopic Compositions (J. S. Coursey, D. J. Schwab, J. J. Tsai and R. A. Dragoset, National Institute of Standards and Technology).Rhenium
Electrons
How it's obtained
Natural isotopes
Isotope Relative atomic mass Abundance 185Re 184.9529545(13) 0.3740(2) 187Re 186.9557501(16) 0.6260(2)