|MadSci Network: Chemistry|
Cu is more"Noble" than is Sn, so that Cu metal would "plate out" and the Sn metal would disasolve. BUT!- "Tin" cans are not made of Sn anymore, they are steel [Fe] with only a very thin [about 20 millionths inch] plating of Sn on the steel. This process is in common use for the recovery of Cu from mine water. the precipitated Cu is called "Cement Copper". It is also used to recover the small amnount of Cu remaining in mine tailings. Essentially, the acidic Cu-containing solution is alllowed to percolate slowly through a bed of scrap iron.The Fe is oxidized and the Cu salt is reduced. Depending on the efficiency of the operation, about 1 - 2 pounds of Fe metal is required for 1 pound of Cu metal.
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