At the refinery the anodes undergo an electrolysis process to remove and refine pure copper from off the anode (small amounts of gold and silver are also recovered from each anode). When done the spent anodes (shown here) still contain a lot of copper, consequently they are reprocessed in a small shaft furnace and returned into the product stream. This constant recycling of material ensures that 99.96% of the copper originally found in the mined ore is recovered.