Gold that is Au can be isolated from gangue by panning, utilizing water in a shallow container to conduit away the lighter gangue from the substantial gold. This technique, likewise called washing, gives exceptionally poor recuperation, particularly of the littler particles, notwithstanding when motorized. Squander piles from this gravity recuperation can be beneficially abused by utilizing more proficient strategies for recuperation. The better gold can be isolated by amalgamation with mercury. At 100°C, mercury can break up 15.7% gold. An amalgamation table comprises of a copper trough which is completely amalgamated. The finely ground blend ("ooze") of gold and gangue is then treated with overabundance mercury and fomented, so that the amalgamated gold particles stick to the table. At interims, this amalgam is scratched off and refined to recoup the gold. Amalgamation gives much better recuperation, yet there is as yet a significant loss of gold. Gold is recuperated as sodium aurocyanide, NaAu(CN)2 on draining of the think with NaCN, sodium cyanide. The measure of gold recoverable by cyanidation of tailings is likely tantamount that initially recuperated by amalgamation, and amalgamation presumably recouped more gold than the underlying washing.
