Polling (metallurgy)
Encyclopedia
Polling is a method employed in the purification of copper
which contains cuprous oxide as an impurity. The impure metal is melted and green wooden poles are used to agitate the molten impure copper. The heat of the copper makes the pole emit a gas which reduces the cuprous oxide to copper.
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
which contains cuprous oxide as an impurity. The impure metal is melted and green wooden poles are used to agitate the molten impure copper. The heat of the copper makes the pole emit a gas which reduces the cuprous oxide to copper.