Cyanide-leach ore is concentrated by carbon-in-pulp adsorption, then eluted and electrowon. Doré bullion is parted in nitric acid to remove Ag, redissolved in aqua regia, and reduced back to Au with SO2 or oxalic acid.
Research Elements Au · atomic number 79 Transition metal · period 6, group 11 [Xe] 4f14 5d10 6s1 Shells: 2, 8, 18, 32, 18, 1 Valence electrons: 1 in the outer shell (6s1), and 10 in 5d10 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).Gold
Electrons
How it's obtained
Natural isotopes
Isotope Relative atomic mass Abundance 197Au 196.96656879(71) 1