Liquation

Liquation, a metallurgical process in which a metal is separated from a mixture by so regulating the heat in a liquation furnace that one of the metals, if necessary alloyed with another metal added for the purpose, melts and is drawn off from the furnace, leaving the other still solid. Thus from an impure form of copper, obtained in the smelting of the metal, and known as black-copper, the silver present is extracted by first adding a quantity of lead, and then subjecting to moderate heat, whereby the lead and silver form an alloy which melts, and is run off from the copper. The silver is afterwards separated by one of the numerous processes available, e.g. Pattinson's or Parke's.